Ukukhuluphala nokulutha komzimba: I-Overurops ye-Neurobiological. (2012) uNora Volkow

• Umlutha;
• dopamine;
• ukukhuluphala;
• i-prefrontal cortex

Isifinyezo

Ukulutha izidakamizwa nokukhuluphala kubonakala kwabelana ngezindawo eziningana. Kokubili kungachazwa njengokuphazamiseka lapho ubuthakathaka bohlobo oluthile lomvuzo (ukudla noma isidakamizwa) buba nehaba ngokuhlobene, futhi kulimaze abanye umvuzo. Kokubili izidakamizwa nokudla kunemithelela enamandla yokuqinisa, okuyingxenye eqondiswe ukwenyuka okungazelelwe kwe-dopamine ezikhungweni zemiklomelo yobuchopho. Ukwanda okungazelelwe kwe-dopamine, kubantu abasengozini, kungadlula izindlela zokulawula ubuchopho be-homeostatic. Lokhu kufana kudale intshisekelo ekuqondeni ukuba sengozini okwabiwe phakathi kokulutha nokukhuluphala.

Ngokucashile, baphinde bafaka impikiswano evuthayo. Ngokukhethekile, izifundo zokucabanga kobuchopho seziqala ukudalula izici ezijwayelekile phakathi kwalezi zimo ezimbili futhi zenza ezinye iziyingi zobuchopho ezigcwele okwedlulele ezingasebenzi ngaphansi kwezici ezibucayi.

Imiphumela ehlanganisiwe iphakamisa ukuthi bobabili abagqila nabanomlutha wezidakamizwa bahlupheka ngenxa yokulimala ezindleleni ze-dopaminergic ezilawula amasistimu we-neuronal angahlobene kuphela nokuzwela umvuzo kanye nesisusa sokukhuthaza, kodwa futhi nesimo, ukuzithiba, ukuphindaphinda ukucabanga kanye nokuqwashisa okuqondayo.

Ngokufana, izifundo zibuye ziveze umehluko phakathi kwazo ezigxila endimeni ebalulekile izibonakaliso zephutha ezibandakanya ukulawulwa kokudla kwasekhaya kokudla kokudla. Lapha, sigxila ezingxenyeni ezingaphansi ezabiwe ze-neurobiological of obesity kanye nomlutha.

Background

Izidakamizwa zokuhlukumeza zithinta izindlela ze-neuronal ezilingisa isisusa sokudla ukudla, ngakho-ke, akumangazi ukuthi kunokweqiwa kwezinqubo ze-neuronal ezifakwe ekulahlekelweni kokulawula kanye nokusetshenziswa ngokweqile kokudla okubonwa ukukhuluphala nasekudleni okuphoqayo wezidakamizwa ezibonwe umlutha.

Okusemaphakathi kwalezi zindlela ezimbili ukuphazamiseka kwezindlela zomqondo dopamine (DA), ezilungisa izimpendulo zokuziphatha ekuvuseleleni imveloi. Ama-dopamine neurons ahlala endaweni ye-midbrain nuclei (indawo ye-ventral tegmental noma i-VTA, kanye ne-substantia nigra pars compacta noma i-SN) leyo projekthi eya ku-striatal (nucleus accumbens noma NAc kanye ne-dorsal striatum), i-limbic (amygdala ne-hippocampus) kanye nezifunda zecortical (preortalal cortex, i-cingulate gyrus, isigxobo sesikhashana) futhi silingise isisusa nokuqina kwemizamo edingekayo ukufeza izimilo ezidingekayo ekusindeni. To ukufezekisa imisebenzi yayo, ama-neurons we-DA athola ukuqagela okuvela ezifundeni zobuchopho ezibandakanya izimpendulo ze-autonomic (ie i-hypothalamus, ubuchopho), inkumbulo (i-hippocampus), ukubuyiswa kwemizwa (i-amygdala), i-arousal (thalamus) nokulawulwa kokuqonda (i-cortex yangaphambili kanye ne-cingate) ngokusebenzisa indawo enkulu uhlu lwama-neurotransmitters nama-peptides.

Ngakho-ke, akumangazi ukuthi ama-neurotransmitters afakwe ekuziphatheni okufuna izidakamizwa nawo ayafakwa ekudleni kokudla futhi, ngakolunye uhlangothi, ukuthi ama-peptides alawula ukudliwa kokudla nawo anethonya kwimiphumela yokuqinisa izidakamizwa (Amathebula 1 futhi 2). Kodwa-ke, ngokungafani kakhulu nezidakamizwa ezenzo zazo zidalwa yimiphumela yazo eqondile ekhemisi ebuchosheni ivuza indlela ye-DA (NAc kanye ne-ventral pallidum), umthethonqubo wokuziphatha kokudla yingakho izimpendulo ekudleni, zilungiswa izindlela eziningi zomngcele neziphakathi ukudlulisela ngqo noma ngokungaqondile imininingwane ebuchosheni bomvuzo womqondo we-DA ngendima ethile evelele ye-hypothalamus (I-Fig. 1).

Izimpawu ezigoqukayo zihlanganisa ama-peptides nama-hormone (isib. I-leptin, i-insulin, i-cholecystokinin noma i-CCK, i-tumor necrosis factor-α) kodwa futhi nezakhi zomzimba (isib. Ushukela kanye ne-lipids), ezihanjiswa nge Ukuxhumana kwe-vagus nerve kuthambo le-nusus lodwa futhi ngqo ngokusebenzisa ama-receptors akhiwe kwi-hypothalamus nakwezinye izindawo zobuchopho ze-autonomic kanye ne-limbic. Lezi zindlela zokusayina eziningi ziqinisekisa ukuthi ukudla kuyadliwa lapho kudingeka, noma ngabe iyiphi yalezi zindlela ezingasebenzi ihluleka. Kodwa-ke, ngokufinyelela okuphindaphindiwe kokudla okuthandekayo, abanye abantu (bobabili abantu kanye nezilwane zaselabhorathri) bangagcina sebecashile izinqubo zokuvimbela izinkomba zibonisa ukugcwala futhi baqale ukudla ngenkani ukudla okuningi naphezu kokudla ngokweqile kanye nokuxwaya lokhu kuziphatha kule icala labantu. Lokhu kwehla kokulawula kanye nephethini yokuphoqelela yokudla okucindezelayo kukhumbuza amaphethini wokudla izidakamizwa akubonwa kumlutha futhi kuholele encazelweni yokukhuluphala njengendlela 'yokuluthwa kokudla' [1].

Ubuchopho be-DA buvuza ama-circry, alungisa izimpendulo endaweni ezungezile, andisa amathuba okuziphatha okukusebenzisa (ukusetshenziswa kokudla noma ukudla izidakamizwa) kuzophindwa lapho behlangabezana nokuqiniswa okufanayo (ukudla okuthile noma izidakamizwa). Ukuphazanyiswa kwesekethe yemivuzo ye-DA kuye kwaba nomthelela ekulahlekelweni kokulawula okubonakalayo kuwo umlutha nokukhuluphala ngokweqile [2], yize izindlela zomzimba eziphazamisa ukusebenza kwamasekethe we-DA, kufaka phakathi lezo ezithintekayo emvuzweni (i-ventral striatum) nasekwakheni umkhuba (dorsal striatum), zibonisa ukwehluka okucacile [3]. Ngaphezu kwalokho, ukuzithiba nokuthatha amandla okuphoqayo (noma ngabe ukudla noma izidakamizwa) kwenzeka ngokuqhubekayo okubonakalayo, kuthonywa kakhulu umongo, ongahamba usuka kolawulo luphelele ungabi nakulawula nhlobo. Iqiniso lokuthi umuntu ofanayo angakwazi ukulawula kangcono kwezinye izimo kunakwezinye libonisa ukuthi lezi zinqubo ezinamandla neziguquguqukayo ebuchosheni. Kulapho la maphethini (ukulahleka kokulawula nokusebenzisa okuphoqayo) eba khona eqinile futhi elawula indlela yokuziphatha nokukhetha komuntu lowo, yize kunemiphumela emibi, lapho isimo se-pathological esifana nomqondo wokulutha singabhenelwa. Kodwa-ke, njengoba iningi labantu abadla izidakamizwa lingamlutha, iningi labantu elidla ngokweqile lilawula amandla alo okudla kwezinye izikhathi kodwa hhayi kwabanye.

Kodwa-ke, impikiswano yokuthi ngabe ukukhuluphala kukhombisa 'umlutha wokudla' kwehlulekile ukucabanga ngobukhulu baleziziphazamiso ezimbili.

Iziphakamiso zenziwe futhi zokubonisa umlutha wezidakamizwa njengesifo esithathelwanayo [4, 5], ewusizo ekuhlaziyeni izinhlaka zayo zenhlalo, zezifo zezomnotho kanye nezomnotho [4, 6] kepha kuholele emcabangweni wokuthi izidakamizwa zifana ne-ejenti ethelelekile nokuthi umlutha ungaxazululwa ngokuqeda izidakamizwa. Okukhohlakele yinkolelo yokuthi ukuqeda ukudla okunempilo kungaxazulula 'umlutha wokudla'. Kepha lolu hlaka lwenkambiso olugxiliwe yi-ejenti luyandiza ebusweni bokuqonda kwethu kwamanje kwezidakamizwa (namanye amaphethini wokuziphatha, kufaka phakathi ukudla okudumile) njengengxenye yomndeni omkhulu futhi onamandla we-'igigger ', onekhono lokuveza, ngaphansi kwesimo esifanele ( kwezemvelo) izimo, ubungozi obukhona (beological).

Ekugcineni, le mpikiswano ibuye ivinjelwe igama elithi 'umlutha', elihlanganisa isihlamba esixhumene nesici somlingiswa, okwenza kube nzima ukwedlulisa ukuqonda kwalo okungekuhle. Lapha, siphakamisa isikhundla esibona iqiniso lokuthi lezi zifo ezimbili zabelana ngezinqubo ze-neurobiological okuthi, uma ziphazanyiswa, zingaholela ekusetshenzisweni okuphoqelekile nasekulahlekelweni kolawulo ekuqhubekeni kobukhulu, ngenkathi futhi kufaka nezinqubo ezihlukile ze-neurobiological (I-Fig. 2). Sethula ubufakazi obukhulu, emazingeni ahlukahlukene we-phenomenological, wezingxenye ezihlanganyelwe ze-neurobiological.  

Isifiso esikhulu sokufuna nokudla isidakamizwa kungenye yezimpawu zokulutha. Ucwaningo lwe-Multidisciplinary luxhumanise isifiso esinamandla kangaka sokuzivumelanisa nokujikeleza kwengqondo ophethe okulindelwe nokuhlola izinhlangano zemivuzo nokufunda ezinemikhuba yokuziphatha nezindlela zokuziphatha ezizenzakalelayo [7]. Ngokubambisana, kukhona ukuphazamiseka emibuthanweni ebandakanyeka ekuzithibeni nasekwenzeni izinqumo, ekuqondeni nasekwenzeni isimo somqondo nokucindezelwa [8]. Le modeli esebenzayo yokulutha nayo ingasetshenziswa ukuqonda ukuthi kungani abanye abantu abakhuluphele bakuthola kunzima kangaka ukulawula kahle ukubamba kwabo kwe-caloric futhi balondoloze amandla e-homeostasis. Kubalulekile ukusho ukuthi sisebenzisa 'ukukhuluphala' ngenhloso yokulula, ngoba lokhu kuhlaziya okubonakalayo kuhlanganisa nabantu abangawona abakhuluphele abanenkinga yokudla okuthile (isib. Ukulimala kokudla okungahambi kahle [BED] kanye ne-anorexia nervosa) [9, 10], futhi okungenzeka ukuthi zibandakanye ukungalingani emibuthanweni yomvuzo nokuzithiba.

Ukuvela kokuziphatha kokudla kwaqhutshwa yisidingo sokuthola amandla e-homeostasis adingekayo ekusindeni futhi kwakhiwa izindlela eziyinkimbinkimbi zokulawula ezibandakanya i-central (isib. Hypothalamus) kanye ne-peripheral (isib. Isisu, ipheshana lesisu, izicubu zamafutha). Iningi lomehluko phakathi kokuluthwa umlutha nokukhuluphala kwama-pathophysiologies avela kokungasebenzi kuleli zinga lomthethonqubo, okungukuthi, i-homeostasis yamandla. Kepha izimilo zokuziphatha ziphinde zithonywe ngolunye uhlangothi lomthethonqubo olufaka ukucubungula imivuzo ngokusayinda kwe-DA kanye nekhono lakhona lokufaka isikimu esihlobene nokudla okuzobe sekuvusa isifiso sokudla okuhlobene. Ucwaningo luveza izinga eliphakeme lokuxhumana phakathi kwalezi zinqubo ezimbili zokulawula, okuthi umugqa phakathi kokulawulwa kwe-homeostatic kanye ne-hedonic yezindlela zokuziphatha zokudla usuqala ukufiphala. (Amathebula 1 futhi 2). Isibonelo esihle ubufakazi obusha bozalo, i-chemacological ne-neuroimaging entsha ekhombisa amathonya aqondile ama-peptide mahormone (isib. I-peptide YY [PYY], ghrelin ne-leptin) ezifundeni ezenziwe yi-DA kufaka phakathi lezo ezibandakanya umvuzo (i-VTA, NAc ne-porral pallidum), Ukuzithiba (i-cortices yokuqala), ukuqonda (i-cingulate, insula), imizwa (amygdala), imikhuba (i-dorsal striatum) nememori yokufunda (hippocampus) [11].

Dopamine esikhungweni samanethiwekhi obuchopho ukubuyela ekuvuseleleni kokuvuselela imvelo

Cishe lonke uhlelo oluyinkimbinkimbi luthembeka kwinethiwekhi ehleleke kahle ekhulumisana ngokuhwebelana okusebenzayo phakathi kokusebenza kahle, amandla kanye nokuvela. Kuye kwaphawulwa ukuthi ukutadisha kancane kwezinsizakusebenza zamanethiwekhi anjalo kunikeza ezinye zezindlela ezinhle zokuqonda i-pathogenesis yezifo [12]. Ezimweni eziningi, lawa amanethiwekhi ahlelwe ngendlela yokwakha esetshenziselwa ukubizwa ngokuthi 'i-bow tie' [12], lapho umugqa onqenqemezela okokufaka okuningi okungahle uguqulele kwinani elincane lezinqubo ngaphambi kokuthandela futhi ekungafani kwemiphumela. Ukuziphatha kokudla kuveza isibonelo esihle salokhu kwakhiwa lapho i-hypothalamus igcina khona 'ifindo' le-mettii bowtie (I-Fig. 3a) futhi izindlela ze-DA zigcina 'ifindo' lokuphinda lisebenze kwizisusa zangaphandle ezibalulekile (kufaka phakathi izidakamizwa nokudla) kanye nezimpawu zangaphakathi (kufaka phakathi ukusayinwa kwe-hypothalamic namahomoni afana ne-leptin ne-insulin; I-Fig. 3b). Njengoba i-midbrain DA neurons (zombili i-VTA kanye ne-SN) ihlanganisa izimpendulo ezifanele zokuziphatha esimweni esinamandla sangaphandle nangaphakathi, zibonisa 'ifindo' elibucayi elinezibophelelo zalo ezibhekene nokufakwa okungatheni kokufaka okuningi okubanzi, kufaka phakathi izidakamizwa kanye nezidakamizwa umvuzo wokudla.

Indima ye-dopamine emvuzweni omkhulu wezidakamizwa nokudla

Izidakamizwa zokuhlukumeza zisebenza emvuzweni nasemibuthanweni eyengeziwe ngezindlela ezahlukene; kodwa-ke, konke kuholele ekunyukeni okuqinile kwe-DA kwi-NAc. Kuyamangaza ukuthi ubufakazi buqongelela ukuthi izimpendulo ezifanayo zedopaminergic zixhunyaniswa nomvuzo wokudla nokuthi lezi zinqubo kungenzeka zibambe iqhaza ekusetshenzisweni kokudla ngokweqile kanye nokukhuluphala. Kuyaziwa ukuthi ukudla okuthile, ikakhulukazi lezo ezinoshukela namafutha, kunomvuzo onamandla [13] and kungadala ukuziphatha okuluthayo-okufana nemfuyo yezilwane zaselebhu [14, 15]. Kodwa-ke, impendulo yokudla kubantu, iyinkimbinkimbi kakhulu, futhi ayithonyelwanga nje ngokwaziwa kwayo kepha futhi nokutholakala kwayoty (amaphethini wokuvinjelwa kanye nokudla ngokweqile, okubizwa ngokuthi yi-topography yokudla [16]), ukukhanga kwayo okubukwayo, ezomnotho nezikhuthazi (ie, 'super sizing' Izipesheli, amasosha we-soda), izindlela zokuxhumana nabantu zokudla, ukuqinisa okunye nokukhangiswa [17].

Ukudla okunama-kilojoule aphezulu kungakhuthaza ukudla ngokweqile (okusho ukuthi ukudla okungafakwanga kusuka ezidingweni ezinamandla) futhi kubangele ukuzihlanganisa okufundile phakathi kovuseleli nomvuzo (isimo). In amagama okuvela kwemvelo, le mpahla yokudla okungathandeki yayisetshenziselwa ukusizakala lapho imithombo yokudla yayingatholakali futhi / noma ingathembekile ngoba yayiqinisekisa ukuthi ukudla kudliwa lapho kutholakala, okwenza amandla agcinwe emzimbeni (njengamafutha) ukuze asetshenziswe esikhathini esizayo. Kodwa-ke, emiphakathini efana neyethu, lapho ukudla kuningi khona futhi kukhulu, lokhu kuguqulwa sekuphenduke isikweletu esiyingozi.

Ama-neurotransmitters amaningana, afaka i-DA, ama-cannabinoids, ama-opioid, i-gamma-aminobutyric acid (i-GABA) ne-serotonin, kanye nama-hormone kanye nama-neuropeptides abandakanyeka ekulawulweni kwe-homeostatic kokudla, njenge-insulin, i-orexin, i-leptin, i-ghrelin, i-PYY, i-peptide efana ne-glucagon -1 (GLP-1) zifakiwe kumiphumela enomvuzo yokudla nezidakamizwa (Amathebula 1 futhi 2) [18-21]. Kulezi, i-DA iphenywe kabanzi futhi yiyona ebonakala kakhulu. Ucwaningo kuma-rodents luveze ukuthi, lapho kuvezwa okokuqala emhlanganweni wokudla, ukudubula kwama-neurons e-DA eVTA kukhuphuka ngokwenyuka okuholela kokukhishwa kwe-DA e-NAc [22]. Tnabu futhi ubufakazi obukhulu bokuthi izibonakaliso eziphelela ezilinganisa ukudla zidla ngokwezenzo zazo ngokwazisa nge-hypothalamic signation ku-VTA kodwa nangemiphumela yazo eqondile ku-VTA DA ngaphezulu-accumbens kanye ne-tseleng-limbicways. Ama-peptides / ama-Orexigenic peptides / ama-hormone akhulisa umsebenzi wamaseli we-VTA DA futhi andise ukukhishwa kwe-DA e-NAc (okuhlosiwe okuyinhloko kwe-VTA DA neurons) lapho kuvezwa isisusa sokudla, kanti ama-anorexigenic avimba ukudubula kwe-DA futhi kunciphe ukuphuma kwe-DA [23]. Ngaphezu kwalokho, ama-neurons aku-VTA kanye / noma i-NAc aveza i-GLP-1 [24, 25], ghrelin [26, 27], leptin [28, 29], insulin [30], i-orexin [31] nama-melanocortin receptors [32]. Ngakho-ke, akumangazi ukuthi inani elandayo lezifundo libika ukuthi la mahomoni / ama-peptide angalinganisa imiphumela emihle yezidakamizwa zokuhlukumeza (Ithebula 1), okubuye kuhambisane nokutholakele kwezimpendulo ezifakiwe kwimivuzo yezidakamizwa kumamodeli ezilwane okukhuluphala [33, 34]. In bantu, kuye kwaba nemibiko yobudlelwano obubi phakathi kwe-body mass index (BMI) nokusetshenziswa kwezidakamizwa okungekho emthethweni kwakamuva [35] nobudlelwano phakathi kokukhuluphala nengozi ephansi yokuphazamiseka kokusebenzisa izidakamizwa [36]. Ngempela, abantu abakhuluphele babonisa amazinga aphansi e-nicotine [37] kanye nokuhlukunyezwa kwensangu [38] kunabantu abangawona omningi ngokweqile. Ngaphezu kwalokho, ukungenelela kwe-juxtaposed okwehlisa i-BMI futhi kunciphise amazinga e-insulin ne-leptin kuthuthukisa ukuzwela kwezidakamizwa ze-psychostimulant [39]. Lokhu kuyahambisana nokuqagela [40] futhi kwezokwelapha [41] ucwaningo olukhombisa ubudlelwane obunamandla phakathi kwezinguquko kuma-neuroendocrine amahomoni (isib. insulin, leptin, ghrelin) okubangelwa ukuvinjelwa kokudla kanye nokusayinda kobuchopho be-DA kanye naleyo mibiko yakamuva yobudlelwano phakathi kobuntu bumlutha nokuziphatha okungalungile kokulandela ukuhlinzwa kwe-bariatric [42, 43]. Yenziwe ndawonye, ​​le miphumela iphakamisa ngokuqinile ukuthi kungenzeka ukuthi ukudla nezidakamizwa kungaqhudelana izindlela zokuthola umvuzo.

Izifundo zokucabanga ngobuchopho seziqala ukuhlinzeka ngemikhondo ebalulekile maqondana nokujikeleza okusebenzayo kokusebenza. Isibonelo, ezifundweni ezinempilo, ezijwayelekile ezinesisindo somuntu, ukumunca kokudla okudumisayo kukhipha i-DA ku-striatum ngokulingana nezilinganiso zokudla okumnandi [44], ngenkathi ukudla kushukumisela ukusebenza kwezifunda zobuchopho eziyingxenye yokujikeleza kwengqondo kwengqondo [45]. Kubikwe futhi muva nje, ukuthi amavolontiya angabantu abaphilile akhombisa ukusebenza okuqinile ngemuva kokuthola i-milkshake, nokuthi ukusetshenziswa kweqhwa okwenziwa njalo kukhombisa izimpendulo zestriatal [46]. Olunye ucwaningo lokuqagela lukhombisile nokuthi, kuyahambisana nokutholakele ezilwaneni zaselebhu, i-anorexigenic peptides (isib. Insulin, leptin, PYY) kwehlisa ukuzwela kohlelo lomvuzo wobuchopho emvuzweni wokudla, kanti okuyilapho i-orexigenic (isib. Ghrelin) ikukhulisa (bona ukubuyekezwa [47]).

Nokho, njengoba kunjalo ngezidakamizwa kanye nokuluthwa umlutha, ukunyuka okufakwa kukudla ku-DA yesimangaliso kuphela akuchazi umehluko phakathi kokudla okujwayelekile nokudla okuphoqelela okweqile ngoba lezi zimpendulo zikhona kubantu abanempilo abangadli ngokweqile. Ngakho-ke, ukuzivumelanisa nokwehla komgwaqo kungenzeka kubandakanyeke ekulahlekelweni kokulawula ukusetshenziswa kokudla njengoba nje kunjalo ngokudla izidakamizwa.

Ukushintshela ekusebenziseni okuphoqelelayo

Indima kaDopamine ekuqiniseni inzima kakhulu kunokufaka amakhodi kuphela ngenjabulo ye-hedonic. Ngokuqondile, izikhuthazi ezibangela ukwanda okusheshayo nokukhulu kwi-DA zenza izimpendulo ezinesimo futhi zikhuthaze ukuzikhuthaza ukuzithenga [48]. Lokhu kubalulekile ngoba, ngokubonga isimo, isisusa sokungathathi hlangothi esixhunyaniswe kokuqiniswa (noma ngabe isemvelo noma isidakamizwa sokuqinisa izidakamizwa) sithola ikhono ngokwaso lokukhulisa i-DA ku-striatum (kufaka i-NAc) ngokulindela umvuzo, ngaleyo ndlela kunikeze isisusa esinamandla sokwenza futhi sisekele nokuziphatha okufanelekile ukuze ufune umuthi noma ufune ukudla [48]. Ngakho-ke, lapho isimo sesivele senzekile, amasiginali we-DA asebenza njengombikezeli womvuzo [49], ukukhuthaza isilwane ukwenza ukuziphatha okuzoholela ekutheni kudliwe umvuzo olindelekile (isidakamizwa noma ukudla). Ukusuka ezifundweni zokuqala, kunobufakazi bokushintsha kancane kancane kokukhuphuka kwe-DA kusuka ku-NAc kuya ku-dorsal striatum, okwenzeka kukho konke, ukudla nezidakamizwa. Ngokukhethekile, kanti inoveli ezuzisayo evumayo ibamba izifunda zangaphakathi ze-striatum (NAc), ngokuvezwa okuphindaphindiwe, izinkomba ezihambisana nomvuzo bese zibangela ukwanda kwe-DA ezindaweni ezi-dorsal striatum [50]. Lolu shintsho luhambisana nokubandakanyeka kokuqala kwe-VTA kanye nokubandakanyeka okwandayo kwe-SN kanye nenethiwekhi yayo ehambisana ne-dorso-striatal-cortical, enezimpendulo ezihlanganisiwe nezindlela ezihlanganisiwe.

Ukuhlangana okuningana kwe-glutamatergic kuma-neurons e-DA kusuka ezifundeni ezibandakanyeka ekusebenzeni kwezinzwa (i-insula noma i-cortex yangempela gustatory), i-homeostatic (hypothalamus), umvuzo (NAc kanye ne-ventral pallidum), ngokomzwelo (amygdala ne-hippocampus) ne-multimodal (orbitof Pambal cortex [OFC] yolwazi lwe-salience) imininingwane, shintsha umsebenzi wabo ukuphendula imivuzo kanye nezimpawu ezinesimo [51]. Ngokufanayo, ukuqagela kwe-glutamatergic ku-hypothalamus kubandakanyeka ezinguquko ze-neuroplastic ezilandela ukuzila okulandelayo futhi ezilungiselela ukondla [52]. Ngenethiwekhi yomvuzo, ukuqagela okuvela kuma-amygdala kanye ne-OFC kuya kuma-neurons e-DA naku-NAc kuyabandakanyeka ekuphenduleni okunesimo ekudleni [53] kanye nezidakamizwa [54, 55]. IUcwaningo olungelona olwangempela, ucwaningo olukhombisa ukuthi lapho abafundisi besilisa abangawona omningi ebuzwa ukuthi bafuna ukunqanda ukudla ngenkathi bechayelwa izinkomba zokudla, bakhombisa ukunciphisa umsebenzi we-metabolic e-amygdala nase-OFC (kanye ne-hippocampus), i-insula ne-striatum, nokuthi Ukwehla kwe-OFC kuhlotshaniswa nokunciphisa ekulangazelweni kokudla [56]. Ukuvinjwa okufanayo komsebenzi we-metabolic e-OFC (naku-NAc) kuye kwaqapheleka kubahlukumezi be-cocaine lapho bacelwa ukuthi bavimbele ukunxanela kwabo izidakamizwa lapho bechayeka ezinkingeni ze-cocaine [57].

Kufanele kushiwo kulo mongo ukuthi, uma kuqhathaniswa nezinto zokudla, izintambo zezidakamizwa ziyizisulu ezinamandla zokuziphatha okuqinisa amandla okulandela inkathi yokungavunyelwa, okungenani esimeni sezilwane ezingakudliwanga ukudla [I-58]. Futhi, uma sekucinyiwe, izimilo eziqinisa izidakamizwa zitholakala kalula ekubuyiselweni okugcizelelwa kunokuziphatha okuqinisiwe kokudla [58].

Noma kunjalo, umehluko ubonakala njengenye ye-degree kune-mfundo. Impela, ukucindezelwa akuhlobene kuphela nokudla okwandayo kokudla okunempilo kanye nokukhuluphala kwesisindo, kepha ukucindezela okukhulu futhi kuthola ukuxhumana okuqinile phakathi kwe-BMI nokusebenza okungenamandla okuphendula ukusetshenziswa kwe-milkshake ku-OFC [59], indawo yobuchopho enomthelela ekufakweni kwe-salience kanye nogqozi. Ukuncika kwezimpendulo ekunikezelweni kokudla kwesimo sokudla [60, 61] igcizelela indima yenethiwekhi ye-homeostatic ekuphathweni kwenethiwekhi yemivuzo, nayo ethonyeliswa yimigudu ye-neuronal esebenza ukucindezela.

Umthelela wokungasebenzi kahle ekuzithibeni

Ukuvela kwezifiso ezinesimo se-cue bekungeke kube kubi kakhulu uma bekungahlanganiswa nokushoda okukhulayo ebuchosheni bokuvimbela isimilo esingalungile. Ngempela, amandla okuvimbela izimpendulo zangaphambilini kanye nokuzithiba kuzobamba iqhaza ekhonweni lomuntu lokugwema ukuzibandakanya ekuziphatheni ngokweqile, njengokusebenzisa izidakamizwa noma ukudla kudlule iphuzu lokusutha, futhi ngaleyo ndlela kwandise ukuba sengozini kwakhe ekubeni umlutha ( noma ukukhuluphala) [62, 63].

Izifundo ze-Positron emission tomography (PET) zithole ukwehla okubalulekile ekutholakaleni kwe-dopamine 2 receptor (D2R) ekutholakaleni kwezihloko eziluthayo eziqhubeka izinyanga ngemuva kokudukiswa okwenziwe njalo. (kubuyekezwe ku [64]). Ngokufanayo, izifundo zangaphambi kokufunda kuma-prentatent nama-primates angewona awomuntu zikhombisile ukuthi ukudalulwa kwezidakamizwa okuphindaphindiwe kuhlotshaniswa nokuncipha kwamazinga e-striatal D2R kanye naku-D2R ukusayina [65-67]. Ku-striatum, ama-D2Rs aqondisa ukungena ngemvume emzileni ongakhondli we-striatal oqondile ohlela izindawo zangaphambili zecortical; nemithetho yabo ephansi ithuthukisa ukuzwela emiphumeleni yezidakamizwa kumamodeli ezilwane [68], kanti ukwenyusa kwabo kuphazamisa ukusetshenziswa kwezidakamizwa [69, 70]. Ngaphezu kwalokho, ukuvimbela i-striatal D2R noma kusebenze kwe-D1R-expression i-striatal neurons (okuyi-mediate signaling in the ngqo indlela ye-striatal) kuthuthukisa ukuzwela emiphumeleni ezuzisayo yezidakamizwa. [71-73]. Kodwa-ke, isilinganiso lapho kunezinqubo ezifanayo zokulawula eziphikisanayo zemigwaqo eqondile nengaqondile ekuziphatheni kokudla kokudla isalungiswa.

In abantu abayimilutha yezidakamizwa, ukuncishiswa kwe-striatal D2R kuhlotshaniswa nomsebenzi owanciphile wezifunda zangaphambili, i-OFC, i-anterior cingulate gyrus (ACC) ne-dorsolateral prefrontal cortex (DLPFC) [67, 74, 75]. Okwenzeka njenge-OFC, ACC ne-DLPFC kubandakanyeke ekuthambekeni kokuqina, ukulawula inhibitory / umthethonqubo womzwelo nokwenza izinqumo, ngokulandelana, kubhalwe ukuthi ukulawulwa kwabo okungafanele kwe-D2R -ediumedi ye-DA ukusayina ezifundweni eziyimilutha kungathobela inani elikhulisiwe lesisusa sezidakamizwa ekuziphatheni kwabo nasekulahlekelweni kokulawulwa kokudla izidakamizwa [62]. Ngaphezu kwalokho, ngoba ukukhubazeka ku-OFC naku-ACC kuhlotshaniswa nokuziphatha okuphoqelelayo nokungafisi, ukungaguquguquki kokungalungi kwe-DA kwalezi zifunda kungenzeka kube nomthelela ekudleni kwezidakamizwa okuphoqelekile nokungacabangi okubonakala ekuluthweni [76].

Isimo esibuyela emuva sincike ebungozini obukhona obukhona bokuthi kusetshenziswe izidakamizwa ezifundeni zokuqala, okungenzeka ukuthi kwandiswe wukuncipha okuthe xaxa kwe-DriNalXXUMXR okubangelwa ukusetshenziswa kwezidakamizwa okuphindaphindekile. Ngempela, ucwaningo olwenziwe ezifundweni okwakunguye, nakuba zazinobungozi obukhulu bokungadakwa (umlando omuhle womndeni wotshwala), lwalungeyona into edakayo, lwembula ukutholakala kwe-D2R ephakeme kune-ejwayelekile ehambisana nokulimala okuvamile e-OFC, ACC naseDLPFC [77]. Lokhu kuphakamisa ukuthi, kulezi zifundo ezisengozini yokuphuza utshwala, umsebenzi ojwayelekile wangaphambi kokuxhunyaniswa waxhunyaniswa nokuqiniswa kokuqiniswa kwe-striatal D2R, okungenzeka ukuthi bekubavikela ekulweni notshwala. Kuyathakazelisa ukuthi ucwaningo lwakamuva lwezingane zandawonye eziluthayo ngokulutha kwazo ezidakamizweni ezivuselelayo [78] kukhombise umehluko wobuchopho ku-morphology ye-OFC, eyayincane kakhulu kubantwana bezelamani abayimilutha kunakulawulo, kanti ezihlotsheni ezingazifakwanga, i-OFC yayingafani neyokulawula [79].

Ubufakazi bokuqina kwezimpawu ze-D2R yesiginali buye batholakala nakubantu abakhuluphele. Zombili lezi zifundo ezenziwa ngaphambi kokubelethisa nezokwelapha zinikeze ubufakazi bokwehla kwe-striatal D2R, okuthi, nge-NAc, kuxhunyaniswe nomvuzo nange-dorsal striatum ngokusungulwa kwemikhuba kanye nohlelo lokukhuluphala [80-82]. Kuze kube manje, ucwaningo olulodwa oluhlulekile ukuthola ukuncishiswa okubalulekile kwe-DriNUMXR yezibalo phakathi kwabantu abakhuluphele nabalawuli abangalungile kakhulu [83], kungenzeka ukuthi livinjelwe amandla alo aphansi wezibalo (n  = 5 / iqembu). Kubalulekile ukugcizelela ukuthi, yize lezi zifundo zingakwazi ukubhekana nombuzo wokuthi ngabe inhlangano evelayo phakathi kwe-D2R ephansi namaphoyinti aphezulu e-BMI ayimbangela, ukwehla kokutholakala kwe-D2R kuye kwaxhunyaniswa nokudla okuphoqelelwe kumagundane akhuluphele [84] nangomsebenzi we-metabolic onciphile ku-OFC ne-ACC kubantu abakhuluphele [63]. Njengoba kunikezwe ukuthi ukungasebenzi kahle ku-OFC ne-ACC kuholela ekuphoqekeni (bona isibuyekezo [85]), lokhu kungahle kube yingxenye yomshini lapho isibonakaliso se-D2R esisezingeni eliphansi sisiza i-hyperphagia [86, 87]. Ngaphezu kwalokho, njengoba ukuncipha okuhlobene ne-striatal D2R kuhlobene nakho kunganciphisa ukuzwela kweminye imivuzo engokwemvelo, lokhu kusilela kubantu abakhuluphele kungasiza futhi ekunciphiseni ukudla ngokweqile [88]. Kuyafaneleka ukusho ukuthi ukungalingani okukhona phakathi komvuzo wobuchopho nokujikeleza kokuvinjithana kuyehluka phakathi kweziguli ezine-Prader-Willi syndrome (ebonakaliswa yi-hyperphagia ne-hyperghrelinemia) kanye neziguli ezikhuluphele nje [87], okuqokomisa ubukhulu benkimbinkimbi yalokhu kuphazamiseka nokuhlukahluka kwabo.

I-hypothesis yokudla ukudla ngokweqile ihlangene nobufakazi bezinsuku zonke bukhombisa ukuthi ukuncipha komsebenzi we-DA eVTA kuholela ekwandeni okumangazayo ekusetshenzisweni kokudla okunamafutha aphezulu [89]. Ngokufanayo, uma kuqhathaniswa nabantu abanesisindo esijwayelekile, abantu abakhuluphele abethulwe nezithombe zokudla okunekhalori ephezulu (okuyisisekelo abakuso) bakhombisa ukwanda kokusebenza kwe-neural ezifundeni eziyingxenye yomjikelezo wokukhuthaza nowokugqugquzela (i-NAc, dorsal striatum, OFC , ACC, amygdala, hippocampus kanye ne-insula) [90]. Ngokuphambene, ngokulawulwa kwesisindo ejwayelekile, ukusebenza kwe-ACC ne-OFC (izifunda ezibandakanyeka ekubambeni uphawu lwe-NAc) ngesikhathi sokulethwa kokudla okunamakhalori aphezulu kutholakele kungahambisani kahle ne-BMI yabo [91]. Lokhu kuphakamisa ukusebenzisana okunamandla phakathi kwenani lokudla okudliwayo (okubonakaliswe engxenyeni ye-BMI) kanye nokuhlelwa kabusha kwezindawo zemivuzo ekudleni okunama-khalori amaningi (kuboniswa kusebenze kwe-OFC ne-ACC) kubantu abanesisindo esijwayelekile kepha okungabonwa kubantu abakhuluphele.

Ngokumangazayo, abantu abakhuluphele bakhombise ukwenziwa okuncane kokujikeleza komvuzo kokusetshenziswa kwangempela kokudla (kokuqeda amandla umvuzo wokudla) kunabantu abazonda, kanti bakhombise ukwenziwa okuningana kwezifunda ze-somatosensory cortical process that processable paratability when walindela ukusetshenziswa [91]. Ukuqashelwa kokugcina kuhambelana nezifunda lapho ucwaningo lwangaphambilini luveze khona umsebenzi othuthukisiwe ezifundweni ezikhuluphele ezihloliwe ngaphandle kokuvuselelwa okuthile [92]. Umsebenzi othuthukisiwe ezifundeni zobuchopho ocubungula amandla wokuphamba ungenza izifundo ezikhuluphele zivumele ukudla ngaphezu kwezinye iziqiniseko zemvelo, kanti ukuncipha kokuqalisa kwamatshe okuphokophelwe yi-dopaminergic ngokusetshenziswa kwangempela kokudla kungaholela ekunciphiseni ukusetshenziswa ngokweqile njengendlela yokunciphisela ukusayina okubuthakathaka kwe-D2R [93]. Le mpendulo engenangqondo yokusetshenziswa kokudla ekudleni komvuzo kwabantu abakhuluphele kukhumbuza ukuthi i-DA incishisiwe ikhuphuka ngokusetshenziswa kwezidakamizwa kubantu abayimilutha uma kuqhathaniswa nezihloko ezingekho umlutha. [94]. Njengoba kubonwa kumlutha, kungenzeka futhi ukuthi ezinye izinkinga zokudla zingahle zivele kusuka ku-hypersensitivity to cows chakula cows. Impela, kubantu abangawona omkhulu ngokweqile abane-BED, sabhala ngaphezulu kokukhishwa okujwayelekile kwe-DA ngokudonswa kwendabuko (i-caudate) lapho kuvezwa izindlela zokudla futhi lokhu kukhuphuka kwabikezela ubunzima bezindlela zokudla kokuzidla. [95].

I-preortal cortex (PFC) idlala indima ebaluleke kakhulu ekusebenzeni kwesigungu, kubandakanya nokuzithiba. Lezi zinqubo zilungiswa yi-D1R ne-D2R (mhlawumbe futhi i-D4R) futhi ngenxa yalokho, umsebenzi wehlisiwe ku-PFC, womlutha kanye nokukhuluphala ngokweqile, kungenzeka ukuthi ube nomthelela ekuzithibeni okungafanele, ekuphoqeleni nasekukhuthazeni okukhulu. Ukutholakala okuphansi kunokwejwayelekile kwe-D2R esimweni sabantu abakhuluphele, esihlotshaniswe nomsebenzi wehlisiwe ku-PFC kanye ne-ACC [63] ngakho-ke kungenzeka ukuthi ufake isandla ekuphepheni kwabo kokuntuleka kokudla. Ngempela, ukuhlangana okungalungile phakathi kwe-BMI ne-striatal D2R kubikwe ku-feta [81] futhi ngokweqile [96] abantu ngabanye, kanye nokuhlangana phakathi kwe-BMI futhi kwehlise ukuphuma kwegazi ezindaweni ezisekuqaleni kubantu abaphilile [97, 98] futhi kwehlise imetabolism yokuqala yangaphambili ezifundweni ezikhuluphele [63] ukusekela lokhu. Ukuqonda okungcono izindlela eziholela ekusebenzeni kwe-PFC okhubazekile (noma umlutha) kungasiza ukuthuthukiswa kwamasu wokuqamba, noma mhlawumbe ukubuyisa emuva, ukulimaza okuthile kwizizinda ezibalulekile zokuqonda. Isibonelo, ukwehliswa kokubambezeleka, okuwukuthambekela kokudonsela umvuzo njengomsebenzi wokubambezeleka okwesikhashana kokulethwa kwawo, kungenye yezinto ezenziwa kakhulu ezihlolisisa ubuciko bokukhubazeka maqondana nokuphazamiseka okuhambisana nokuxakwa kanye nokuphoqelelwa. Ukubambezeleka kokubambezeleka kuphenyisiswe ngokuphelele kubahlukumezi bezidakamizwa abakhombisa ukuthandwa ngokweqile kwemivuzo emincane kodwa esheshayo ngokubambezeleka [99]. Kodwa-ke, ucwaningo olwenziwe nabantu abakhuluphele sebeqalile ukuthola ubufakazi bokuthanda kwabo imivuzo ephezulu, esheshayo, yize kunamathuba andayo wokuthola ukulahleka okukhulu okuzayo [100, 101]. Ucwaningo lwakamuva olusebenza ngokusebenza kwengqondo (i-fMRI) olusebenzayo kubantu besifazane abakhuluphele, ngokwesibonelo, luveze umehluko wesifunda ekusetshenzisweni kobuchopho ngesikhathi sokulibaziseka kwemisebenzi yesaphulelo ebekade ibikezela ukuzuza kwesisindo esizayo [102]. Kodwa-ke, olunye ucwaningo lwathola ukuxhumana okuhle phakathi kwe-BMI ne hyperbolic Isaphulelo, lapho esizayo kubi ukukhokha kuncishiswa okungaphansi kokukhokha okuzayo okuzayo [103]. Ngokuthakazelisayo, ukuncishiswa okubambezelayo kubonakala kuncike emsebenzini we-ventral striatum [104] kanye ne-PFC, kufaka phakathi i-OFC [105] nokuxhumeka kwayo kwi-NAc [106], futhi iyazwela okwenziwa yi-DA [107].

Ukungasebenzi okwenziwe ngaphezulu kumasekethe wokukhuthaza

I-Dopaminergic signaling ibuye iguqule isisusa. Izici zokuziphatha ezinjengokuqina, ukuphikelela kanye nokutshala imali okuqhubekayo ukufeza inhloso, konke kuncike ekuguqulweni kwe-DA esebenza ezifundeni ezithile ezihlosiwe, kubandakanya i-NAc, ACC, OFC, DLPFC, amygdala, drial striatum kanye ne-ventral pallidum [108]. Ukusayinwa kwe-DA okuhlanganisiwe kuhlotshaniswa nesisusa esithuthukisiwe sokuthengwa kwezidakamizwa, uphawu lokulutha, yingakho abantu abayimilutha yezidakamizwa bavame ukuzibandakanya ekuziphatheni okwedlulele ukuthola izidakamizwa, noma ngabe kunemiphumela emibi nengathandeki eyaziwayo futhi kungadinga ukuziphatha okuzinze nobunzima zithole [109]. Ngoba ukuthatha izidakamizwa kuba yisiqoqo esiyisisekelo sokuluthwa yizidakamizwa [110], izihloko eziwumlutha zivuswa futhi zigqugquzelwa inqubo yokuthola umuthi kepha zivame ukuhoxa futhi zinganaki lapho zivezwa imisebenzi engahlobene nezidakamizwa. Lolu shintsho lufundwe ngokuqhathanisa amaphethini wokusebenza kobuchopho okwenzeka lapho kuchayeka ezinkombeni ezinesimo nalezo ezenzeka kungabikho zalolu hlobo. Ngokungafani nokwehla komsebenzi wokuqala owabikwa kubahlukumezi be-cocaine abangakhushulwa izidakamizwa noma izidakamizwa (bheka ukubuyekezwa [64]), lezi zifunda zangaphambi kokuqala ziqala ukusebenza lapho abahlukumezi be-cocaine bevezwa ekuvuseleleni okukhanukelayo (kungaba izidakamizwa noma izindlebe) [111-113]. Ngaphezu kwalokho, lapho izimpendulo ze-iv methylphenidate ziqhathaniswa phakathi kwabantu abayimilutha ye-cocaine nabangewona umlutha, owokuqala waphendula ngokunyuka kokudla emzimbeni ku-Aralral ye-ACC ne-medial OFC (umphumela ohambisana nokufisa), ngenkathi owokugcina wakhombisa ukwehla kwe-metabolism kulezi zifunda. [114]. Lokhu kuphakamisa ukuthi ukwenziwa kwalezi zingxenye zangaphambi kokuchayeka kwezidakamizwa kungahle kube ngokuqondile kumlutha futhi kuhlotshaniswe nesifiso esithuthukisiwe somuthi. Ngaphezu kwalokho, ucwaningo olwavusa izihloko eziluthwe yi-cocaine ukuba luvimbe ukunxanela ngenhloso lapho luvezwa ezinkingeni zezidakamizwa luveze ukuthi lezo zifundo ezaphumelela ukuvimbela inkanuko zibonisiwe zancipha imetabolism ku-medC ye-OFC (esebenza ngenani lesisusa sokuqinisa) ubikezela umvuzo) [57]. Lokhu okutholakele kuqinisa ukubandakanyeka kwe-OFC, ACC kanye ne-striatum ekugqugquzeleni okuthuthukile kokuthola umuthi obonakale umlutha.

I-OFC nayo ihilelekile ekubaluleni ukubaluleka kokudla kokudla [115, 116], isiza ukuhlola ubumnandi bayo obulindelekile nokusebenziseka kwayo njengomsebenzi wesimo sayo. Izifundo ze-PET nge-FDG ukukala i-brain glucose metabolism kubantu abajwayelekile-isisindo babike ukuthi ukuchayeka ezinkombeni zokudla kwandise umsebenzi we-metabolic e-OFC, ehambisana nesifiso sokudla [117]. Ukwenza kusebenze kwe-OFC okwenziwe ngcono ngokugqugquzela ukudla kungenzeka kukhombise imiphumela esezansi yedopaminergic futhi kubambe iqhaza ekubandakanyeni kweDA ekushayeleni ukusetshenziswa kokudla. I-OFC ibamba iqhaza ekufundeni izinhlangano eziqinisa umfutho nesimo [118, 119], Isekela yokudla ekhondishina-lokubonisa-sezempi [120] futhi mhlawumbe kunomthelela ekondleni okwedlulele ngaphandle kwezimpawu zendlala [121]. Ngempela, ukulimala kwe-OFC kungaholela ku-hyperphagia [122, 123].

Ngokusobala, eminye umehluko oqondile ekusebenzeni kokuphatha ungaba yingozi yokwehla kokukhuluphala okuthe xaxa kwabanye abantu, njengoba kuvezwa ukuhlaziya kwasekilasini okwedlule kwe-997 graders yesine ohlelweni lokuvimbela ukukhuluphala okwenziwa esikoleni [124]. Kuyathakazelisa ukuthi noma ngabe kusengaphambili, ukuphenywa okuhlukanisiwe kwekhono lezingane lokuzilawula, ukuxazulula izinkinga nokuzibandakanya ekuziphatheni okuqondiswe enhlosweni kwezempilo kuveza ubuchwepheshe bokusebenza okungahambisani kahle nokusetshenziswa kwezidakamizwa kepha nokusetshenziswa kwekhalori eliphakeme ukudla okulula, nokuziphatha kokuhlala phansi [125].

Naphezu kokungahambisani okuthile phakathi kwezifundo, idatha yokucabanga kobuchopho futhi isekela umbono wokuthi izinguquko ezihlelekile nezisebenza ezifundeni zobuchopho ezifakwe ekusebenzeni okuphezulu (kufaka phakathi ukulawulwa kokuvinjelwe) zingahlotshaniswa ne-BMI ephezulu kubantu abahlukile abaphilile. Isibonelo, ucwaningo lwe-MRI olwenziwe kubantu besifazane asebekhulile, besebenzisa i-voxel-based morphometry, lithole ukuxhumana okungekuhle phakathi kwe-BMI namavolumu e-grey ndaba (kufaka phakathi izifunda ezingaphambili), okuthi, e-OFC, kuhlotshaniswe nomsebenzi wokuphatha ophakeme [126]. Sisebenzisa i-PET ukukala imetabolism yobuchopho be-glucose ekulawuleni okunempilo, sibike ukuxhumana okungalungile phakathi kwe-BMI nomsebenzi we-metabolic ku-DLPFC, OFC ne-ACC. Kulolu cwaningo, umsebenzi we-metabolic ezifundeni ezingaphambi kokubikezela ukusebenza kwezifundo ezivivinyweni zomsebenzi wokuphatha [98]. Ngokufanayo, ucwaningo lwe-microson resonance spectroscopic ecwaninga ngeminyaka ephakathi nolawulo lwabadala lubonise ukuthi i-BMI yayihlotshaniswa kabi namazinga e-N-acetyl-aspartate (umaki wobuqotho be-neuronal) kwi-cortex yangaphambili ne-ACC. [98, 127].

Ucwaningo lokuqagela ubuchopho oluqhathanisa abantu abakhuluphele nabazonda kakhulu lubuye lubike le ndaba ephansi ye-grenus ezindaweni ezingaphambili (i-operculum yangaphambili kanye ne-gyrus ephambili yangaphambili) kanye nasesigunjini se-post-central gyrus kanye ne-putamen [128]. Olunye ucwaningo alutholanga mahluko ezindabeni ezi-grey phakathi kwezifundo ezikhuluphele nezincikene; kodwa-ke, siqophe ukuvumelana okuhle phakathi kwenthamo emhlophe yezakhi ezinobuchopho be-basal okhalweni nokulinganisa i-hip ratios, umkhuba owabuyiselwa kancane ngokudla [129]. Ngokuthabisisayo, izindawo ezi-cortical, njenge-DPFC ne-OFC ezibandakanyeka kulawulo lwe-inhibitory, nazo zitholakele ukuthi zenziwa zasebenza kuma-dieters aphumelelayo ngokuphendula isidlo [130], kuphakamisa ithagethi engaba khona yokuziphatha okubucayi ekwelapheni ukukhuluphala (futhi nasekuluthweni).

Ukuzibandakanya kokujikeleza kokuqonda

Ucwaningo lwe-Neuroimaging luveze ukuthi i-insula ephakathi ibamba iqhaza elibalulekile ekunxaneleni ukudla, i-cocaine kanye nogwayi [131-133]. Ukubaluleka kokufakelwa kugqanyiswe ngocwaningo olubike ukuthi ababhemayo ngomonakalo wale ndawo (kodwa hhayi ababhemayo abake bahlaselwa izilonda ezingekho emthethweni) bakwazile ukuyeka ukubhema kalula futhi ngaphandle kokuthola izinkanuko noma ukubuyela emuva [134]. I-insula, ikakhulukazi izifunda zayo ezingaphandle, ihlangene ngokuhlangana nezifunda ezinamandla (isib. I-ventromedial prewardal cortex, i-amygdala, ne-ventral striatum) futhi ibonakala inomsebenzi wokucabanga, ukuhlanganisa imininingwane ye-autonomic ne-visceral ngemizwa kanye nogqozi, ngaleyo ndlela ihlinzeke ngokwazi ukuqaphela kwalezi zinxephezelo [135]. Ngempela, ucwaningo olucashile ubuchopho lubonisa ukuthi i-PFC ene-ventromedial kanye ne-insula kuyizinto ezidingekayo zezijikelezo ezisatshalaliswa ezisekela izinqumo ezingokomzwelo [136]. Ngokuhambisana nalokhu okuqanjiwe, izifundo eziningi zokucabanga ngemibono zibonisa ukwenza kusebenze kwe-insula ngesikhathi sokulangazelela [135]. Ngokuvumelana nalokhu, ukuphinda kwenziwe kabusha kwesifunda ubuchopho kuye kwahlongozwa ukuthi kusebenze njenge-biomarker ukusiza ukubikezela ukubuyela emuva [137].

I-insula ibuye ibe yindawo eyisisekelo yokudlela, ebamba iqhaza ezicini eziningi zokuziphatha kokudla, okunjengokunambitha. Ngaphezu kwalokho, i-rostral insula (exhunywe ku-cortex yokunambitheka okuyisisekelo) inikezela imininingwane ku-OFC ethonya ukumelwa kwayo okubanzi kobumnandi noma inani lomvuzo lokudla okungenayo [138]. Ngenxa yokubandakanyeka kwe-insula kumqondo ongaphakathi womzimba, ekuqwashiseni ngokomzwelo [139] nasogqozi nasemizweni [138], umnikelo wokulimazeka okufakelwe emzimbeni wokukhuluphala kufanele ungamangali. Futhi ngokweqiniso, ukuphazamiseka kwesisu kuphumela ekusetshenzisweni kwe-insula yangemuva, ehambisana nendima yayo ekuqwashisweni kwezindawo zomzimba (kulokhu kugcwala) [140]. Ngaphezu kwalokho, ngokusondelana, kodwa hhayi ngezifundo ezinamafutha, ukuhlukaniswa kwesisu kuholele kusebenze kwe-amygdala kanye nokusebenza ugesi kwangaphakathi kwangaphakathi [141]. Ukuntuleka kokuphendula kwe-amygdalar ezifundweni ezikhuluphele kungakhombisa ukuqwashisa okungenangqondo kwezimo zomzimba ezihlangene ne-satiety (isisu esigcwele). Yize ukucubungula okwenziwe yi-DA kungaphenyiswanga kahle, kuyaziwa ukuthi i-DA iyabandakanyeka ekuphenduleni ukunambitheka kokudla okuphathekayo okuqondiswa ngaphakathi kufakwa [142]. Ucwaningo lokucabanga kwabantu lukhombisile ukuthi ukunambitha ukudla okunambitheka kusebenze ezindaweni ze-insula nezamaphakathi [143, 144]. Ukusayina kwe-DA kungadingeka futhi ukubona okuqukethwe kokudla. Isibonelo, lapho abesifazane abanesisindo esijwayelekile benambitha i-sweetener enama-kilojoule (ama-sucrose), zombili izindawo ezisetshenziselwa ukufaka insula ne-dopaminergic, kuyilapho ukunambitha i-sweetener engenawo ama-calorie (sucralose) kusebenze kuphela ukufakwa [144]. Izifundo ze-Fetese zibonisa ukusebenza okulula kakhulu kunezivumelwano ezijwayelekile lapho unambitha isidlo soketshezi esinoshukela namafutha [143]. Ngokuphambene nalokho, lapho unambitha i-sucrose, izihloko eziye zalulama ku-anorexia amanosa zibonisa ukusebenza okuncane futhi azihlanganisi nemizwa yobumnandi njengoba zibonwa ezilawulweni [145]. Ngaphezu kwalokho, ucwaningo lwakamuva lwe-fMRI oluqhathanise izimpendulo zobuchopho ezethulweni eziphindaphindwayo zokuthokozela nezithombe zokudla ezingathandeki kubantu abangazithembi ngokweqile [146] ithole ushintsho olusebenzayo ekuphenduleni nasekuxhumaneni phakathi kwezifunda ezibalulekile zethekhnoloji yemivuzo ezingasiza ukuchaza ukweqiwa kobuningi bezindawo zokudla kubantu abakhuluphele. Ushintsho olubonisiwe libonisa okokufaka okwedlulele okuvela kuma-amygdala ne-insula; lezi, nazo zingadala ukufundwa kokuphendula kokuvuselela umdlandla kanye nokukhuthaza isisusa sokudla kokudla endaweni ye-dorsal caudate nucleus, engaba nzima ngenxa yokukhanya kokulawula okubuthaka kokuvinjezelwa yizifunda ze-fronto-cortical.

Ukujikeleza kokuphambuka nokuphindeka kwengqondo

Njengoba sekushiwo ngaphambili, ukuqeqesha (ukubeka isimo) ekhokhweni ebikezela umvuzo kuholela ekuqothulweni kwamaseli e-dopaminergic ukuphendula ukubikezela, hhayi kumvuzo uqobo. Ngakolunye uhlangothi, futhi ngokuhambisana nalokhu okunengqondo, kuye kwaqashelwa ukuthi amaseli e-dopaminergic azoshisa ngaphansi kokujwayelekile uma umvuzo olindelekile wehluleka ukwenza imizimba yenyama [147]. Ubufakazi obuqandekayo [148-151] ikhomba ku-habenula njengesinye sezifunda ezilawula ukuncipha kokuxoshwa kwamangqamuzana e-dopaminergic eVTA okungalandela ukwehluleka ukuthola umvuzo olindelekile [152]. Ngakho-ke, ukuzwela okuthuthukile kwe-habenula, ngenxa yokuchazwa kwezidakamizwa okungamahlalakhona, kungabeka ukuphindwaphindwa okukhulu kwezinkomba zezidakamizwa uma kungalandelwa ukusetshenziswa komuthi noma lapho imiphumela yezidakamizwa ingafezekisi umphumela wokulindelwa womvuzo. Ngempela, ukusebenza kwe-habenula, kumamodeli ezilwane okulutha lwe-cocaine, kuhlotshaniswa nokubuyela emuva ekuthatheni izidakamizwa lapho kuvezwa i-cue [153, 154]. Endabeni ye-nicotine, ama-cy5 receptors e-nicotinic ku-habenula avela njengokuguqula izimpendulo eziphikisayo kumithamo emikhulu ye-nicotine [155], kanye ne-α5 ne-α2 receptors ukulungisa ukuhoxiswa kwe-nicotine [156]. Ngenxa yempendulo ephambene ye-habenula kuleyo ye-DA neurons ngokuvezwa komvuzo (ukwenziwa kungasebenzi noma kusebenze) nokusebenza kwayo ngokuvezwa kwesikhuthazi esiphikisayo, sibhekisa lapha ekusayineni okuvela ku-habenula njengokuhambisa okufakwayo 'okuphambene'.

I-habenula ibukeka idlala indima efanayo maqondana nomvuzo wokudla. Ukudla okumnandi kakhulu kungadonsa ukukhuluphala kumagundane, kanti isisindo sanda sihambisana nokukhuphuka kwe-μ-opioid peptide yokubopha kuma-basolateral kanye ne-basomedial amygdala. Ngokuthokozisayo, i-medial habenula ikhombise ukubopha okungaphezulu kakhulu kwe-μ-opioid peptide (cishe i-40%) ngemuva kokuchayeka kokudla okuthandekayo kumagundane athola isisindo (lawo aqeda ukudla okuningi) kepha hhayi kulawo angazange [157]. Lokhu kusikisela ukuthi i-habenula ingahle ibandakanyeke ekudleni ngokweqile lapho ukudla okuthandekayo kutholakala. Ngaphezu kwalokho, ama-neurons ku-rostromedial tegmental nucleus, athola okokufaka okukhulu okuvela kwi-lateren habenula, iphrojekthi eya kuma-neurons we-VTA DA futhi asebenze ngemuva kokuncishwa kokudla [158]. Lokhu okutholakele kuhambisana nendima ye-habenula (kokubili ngokwe-medical neye-lateral) ekuvumelaneni nezimpendulo zokuvusa amandla noma kwizimo zokuncishwa njengasikhathi sokudla noma sokususwa kwezidakamizwa.

Ukubandakanyeka kwe-habenula njengehabhu yokuntengantenga ngaphakathi kwamanethiwekhi angokomzwelo kuyahambisana namamodeli wangaphambilini wokulutha owabeka leyo mizwa yokugcizelela kokucabanga kanye nemood engemihle (iqondwe ngokuzwela okwengeziwe kwe-amygdala kanye nokwanda kokubonisa noma i-corticotrophin-releasing factor) idonsela izidakamizwa ngokumlutha [159]. Izimpendulo ezifanayo zokuphelelwa amandla (kufaka phakathi ukukhuphuka kabusha kwengcindezi, imizwa engemihle kanye nokungajabuli) nazo zingasiza ekusetshenzisweni kokudla ngokweqile emafutheni nasezimweni eziphakeme zokuphinda ubuye lapho udla ngemuva kokuchayeka emcimbini ocindezelayo noma okhungathekisayo.

Ngokuvala

Amandla wokumelana nesifiso sokusebenzisa isidakamizwa noma udle okudlula lapho kugcwala khona ukwanelisa ukudinga ukusebenza ngokufanele kwemijikelezo ye-neuronal ebandakanyeka kulawulo lwe-top-phansi ukuphikisana nezimpendulo ezinemibandela ezivusa isifiso sokudla ukudla / isidakamizwa. Ukuthi izinhlobo noma zokukhuluphala ngokweqile kufanele zichazwe yini noma cha [160], kukhona imibuthano eminingana ebonakalayo ebuchosheni [2], okungasebenzi kahle kwembula ukufana kwangempela nokunengqondo kwezempilo phakathi kwalezi zinkinga ezimbili. Isithombe esivelelayo ukuthi ukukhuluphala, okufana nokuluthwa yizidakamizwa [226], kuvela ngenxa yokuqhutshwa okungalingani ezigabeni ezahlukahlukene ezifakwe kumvuzo / ubukhulu, isishukumiso / idrayivu, imizwa / ukucabanga kabusha kwengqondo, inkumbulo / isimo, umsebenzi omkhulu / ukuzithiba kanye nokuqonda, ngaphezu kokungalingani kulawulo lwe-homeostatic ukudla.

Imininingwane eqoqwe kuze kube manje isikisela ukuthi kungukungafani phakathi kokulindelwe kwemiphumela yezidakamizwa / yokudla (izimpendulo ezinesimo) kanye nesipiliyoni somvuzo ongashintshiwe osekela ukuziphatha kokuthatha izidakamizwa ngokweqile emzameni wokuthola umvuzo olindelekile. Futhi, noma ihlolwe ngesikhathi sokuqala noma kokudotshwa kokudinwa / kokudla, izihloko eziwumlutha / ezikhuluphele zibonisa i-D2R ephansi ku-striatum (kufaka ne-NAc), ehlotshaniswa nokuncipha komsebenzi wesisekelo ezindaweni ezithinta ubuchopho obuphakathi kufakwe ku-salience factorution (OFC) nokulawulwa kokuvinjwa kokuvinjwa (I-ACC ne-DLPFC), okuphazamiseka kwayo kubangela ukukhuthazeka kanye nokuxoshwa. Ekugcineni, ubufakazi buye babuka iqhaza elibalulekile mayelana nokujikeleza nokuqonda okuphakathi kokungalingani okuhlelekile okuholela ekungeneleleni okucindezelayo kwezidakamizwa noma kokudla. Njengomphumela wokuphazamiseka okulandelanayo kulawa masekethe, abantu bangathola (i) inani lesishukumisela lesidakamizwa / lokudla (lesibili kuya ezinhlanganweni ezifundile ngesimo nemikhuba) ngokulahlwa kwabanye abaqinisi (okuyisisekelo ukuze kunciphise ukuzwela komjikelezo womvuzo ), (ii) ikhono elingasebenzi kahle lokuvimbela izinhloso (eziqondiswe kunhloso) ezihloselwe yisifiso esinamandla sokuthatha isidakamizwa / ukudla (okwesibili kuya kokungasebenzi okuphuthumayo) okuholela ekucindezelweni kwezidakamizwa / kokudla kanye (iii) nokucindezelwa okuthuthukile kanye 'nokusebenza okuphindaphindekayo' okuholela ekuphuzeni izidakamizwa okuphoqelela ukubalekela izwe eliphikisayo.

Ukufana okuningi kwemikhuba nokuziphatha okukhonjwa phakathi komlutha nokukhuluphala kubonisa ukubaluleka kwezindlela zokwelapha ezifanayo zokuphindaphindeka zombili lezi zinkinga. Izindlela ezinjengalezi kufanele zizame ukwehlisa izakhiwo eziqinisa izidakamizwa / zokudla, zivuselele kabusha / zithuthukise izakhiwo ezinomvuzo zokuqinisa okunye, izinhlangano ezifundile ezinemikhawulo, zithuthukise inkuthazo yemisebenzi engahlobene nezidakamizwa / yokudla, yehlise ukuphinda zisebenze, ithuthukise imizwa kanye qinisa ukuzithiba okujwayelekile

Ukungqubuzana kwesitatimende senzalo

Akukho kungqubuzana kwesitatimende senzalo.