Agasti 24, 2015
Ukutya kokutya kulawulwa ziinethiwekhi ezininzi ze-neuron:- isekethe eqhuba ukutya kokutya ekuphenduleni iimfuno zamandla omzimba (blue) ibandakanya i-nucleus yeparaventricular (PVN), i-lateral hypothalamus (LH), i-nucleus tractus solitarius (NTS) kunye ne-nucleus arcuatus. (ARC). Ii-neurons ze-ARC ziyasebenza xa amanqanaba amandla ephantsi. Bakhupha iimolekyuli ezimbini (i-NPY kunye ne-AgRP) ukukhuthaza ukutya.- isekethe "yolonwabo" enxulumene nokutya (epinki) ibandakanya indawo ye-ventral tegmental (VTA), imvelaphi ye-dopaminergic neurons, i-striatum kunye ne-nucleus accumbens (Nacc ). Ukukhutshwa kwe-Dopamine kwisekethe yomvuzo kuya kukhuthaza ukutya okunamafutha aphezulu kunye ne-high-carbohydrate.Xa umsebenzi we-NPY/AgRP neuron uphazamisekile, ukuthathwa kokutya kuqhutywa kakhulu yisekethe yomvuzo. Ukuziphatha kokutyisa ke ngoko akunxulumananga kangako neemfuno zemetabolism kwaye kuxhomekeke ngakumbi kwizinto zokusingqongileyo ezifana noxinzelelo okanye iimpawu zencasa yokutya. Ikhredithi: Serge Luquet
Iqela kwi-Laboratoire biologie fonctionnelle et adaptative (CNRS/Université Paris Diderot) iphande indima ehambelana neemfuno zamandla kunye "nolonwabo" lokutya ekutyeni ukutya. Abaphandi bafunde iqela le-neurons kwiimpuku. Baye baqaphela ukuba xa umsebenzi we-neuron usemngciphekweni, indlela yokuziphatha yokondla iba nganeno kangako kwiimfuno zemetabolism yomzimba kwaye ixhomekeke ngakumbi kwincasa yokutya. Ezi ziphumo zinokuchaza ukuba ufikelelo lula kangakanani na ekutyeni okukhangayo kunokuba negalelo kukuphazamiseka kokutya okunyanzelekileyo kunye nokuthanda ukutyeba. Lo msebenzi usandula ukupapashwa kwi Cell Metabolism.
Ukuziphatha kokutyisa kulawulwa ziindlela ezahlukeneyo zemithambo-luvo, ngoko ke isidingo sokutya siqhutywa zizo zombini iimfuno zamandla omzimba kunye nolonwabo olunxulumene nokutya. Kwimeko yanamhlanje apho ukutya okutyebileyo ngamandla kuninzi ngakumbi nangakumbi kwizidlo zethu kwaye apho ii-pathologies ezifana nokutyeba, isifo seswekile kunye nesifo senhliziyo zisanda, kubalulekile ukucacisa ukuba ezi zijikelezo ze-neural zahlukeneyo zibandakanyeka kwaye zixhunyiwe. Ukuqonda amagalelo ahlukeneyo omatshini ogcinayo ukulingana kwamandla kunye nomvuzo (okanye ulonwabo) isekethi iya kwenza kube nokwenzeka ukuphuhlisa unyango olusebenzayo ngakumbi kwezi zifo.
Iqela lophando liphande iqela le neurons kwi-hypothalamus ebizwa ngokuba yi-NPY/AgRP, ezaziwa ngokudlala indima kuyo ukutya. Ezi neurons ziyinxalenye yesekethe egcina ibhalansi yamandla: ikhuthaza ukutya xa ivuliwe, kwimeko yokuzila okanye i-hypoglycemia ngokomzekelo. Ukuza kuthi ga ngoku bebejongwa njengezona njongo ziphambili zokuphuhlisa unyango lokutyeba. Ngokufunda iimpuku ezingenazo ezi neurons, abaphandi babonise ukuba ezi ziyimfuneko ekuqaliseni ukutya xa ukutya kungenalo ixabiso eliphezulu le-hedonic kwaye yimpendulo nje kwiimfuno ze-metabolic. Ngokwahlukileyo koko, banegalelo elincinane ekutyeni xa ukutya kunencasa kakhulu, kunamafutha amaninzi kunye neecarbohydrates.
Xa ezi neurons zingekho okanye zithintelwe, iigundane zisebenzisa ukutya okuncinci okusemgangathweni, nasemva kokuzila ukutya. Ngokwahlukileyo, baya kutya ngokuqhelekileyo ukuba banikwe ukutya okunamafutha aphezulu kunye ne-carbohydrate ephezulu. Uthotho lwemifuniselo lubonise ukuba xa i-NPY/AgRP umsebenzi neuron ibekwe esichengeni, ihomoni eyabakhuthazayo endaweni yoko iya kusebenzisa ii-neuron ezibandakanyekayo kwisekethe yomvuzo. Le ndlela ye-nerve elawulwa yi-dopamine ke ngoko ithatha indawo kwaye iyalathisa indlela yokutya. Isiphumo sisimo sokutyisa esiphazamisekileyo, siqhawulwe kwiimfuno zamandla omzimba kwaye ngokusisiseko sixhomekeke kulonwabo olubangelwa kukutya.
Iimpuku ezifundwe emva koko zatya ukutya okunamafutha aphezulu kunye ne-carbohydrate ephezulu kakhulu kwaye zafumana ubunzima. Ukuziphatha kwabo kokutyisa kwakukwanobuntununtunu ngakumbi kwizinto zangaphandle ezinjengoxinzelelo. Lilonke, ezi mpuku ziyimodeli elungileyo yokondla intuthuzelo.
Iimpuku kolu phononongo ziye zangenelela ngokwemfuza ukuguqula umsebenzi we-neuron we-NPY/AgRP. Ukuqhubeka nokuvezwa kokutya okutyebileyo kwamandla kunokuba neziphumo ezifanayo, ezibangela ukuba ezi neuron zingabi namvakalelo kwaye zithathwe ngumqhubi owahlukileyo endaweni yazo: isekethe yomvuzo. Iziphumo zemikhwa yokutya, enganxulumananga nemetabolism, inegalelo ekuqaliseni kokuphazamiseka okunyanzelekileyo kwaye ithande ukutyeba kakhulu. Ezi ziphumo ke ngoko zinika ukukhanya okutsha kwindima ye-NPY/AgRP neurones ekugcineni ulungelelwaniso lwamandla. Bakwabonisa ukuba ukusebenza kwinqanaba le-pharmacological kula neurons ukunyanga i-hyperphagia kunokuba nemveliso.
Hlola kwakhona: I-neurons yengqondo kunye nokutya kunempembelelo ekuqalekeni kokutyeba kunye nesifo seswekile kwiimpuku
Iinkcukacha ezithe xaxe: "Incasa inokuqhuba ukondla ngokuzimeleyo kwi-AgRP Neurons." I-Cell Metab. 2015 Aug 12. pii: S1550-4131 (15) 00340-X. I-DoI: 10.1016 / j.cmet.2015.07.011
I-Palatability inokuqhuba uKutyisa ngokuzimeleyo kwi-AgRP Neurons
DOI:
http://dx.doi.org/10.1016/j.cmet.2015.07.011
Iimbalasane
- •I-AgRP neurons ibalulekile ukuqhuba ukutya xa ukutya kungancancisi
- •I-AgRP neurons iyakhutshwa xa ukutya kunencasa kakhulu
- •Izilwanyana ezinomsebenzi we-neuron we-AgRP ngumzekelo wokutyisa okuthuthuzelayo
- • Ukuvinjwa kwee-neurons ze-AgRP kukhuthaza ukondla ngomvuzo
isishwankathelo
Ukuziphatha kokutyisa kulawulwa ngokugqibeleleyo yi-homeostatic kunye ne-hedonic neural substrates ezidibanisa imfuno yamandla kunye nokuqinisa kunye nomvuzo wokutya. Ukuqonda igalelo le-homeostatic kunye nokutya okuqhutywa ngumvuzo kuye kwabaluleka ngenxa yomthombo okhoyo okhoyo wokutya okuxineneyo kwamandla kunye nobhubhani wokutyeba. I-hypothalamic agouti-related peptide-secreting neurons (AgRP neurons) ibonelela nge-orexigenic drive engundoqo yokondla i-homeostatic. Ukusebenzisa iimodeli ze-neuronal inhibition okanye ablation, sibonisa ukuba impendulo yokondla kwi-ghrelin ekhawulezayo okanye i-serotonin receptor agonist ixhomekeke kwi-neurons ye-AgRP. Nangona kunjalo, xa kubonelelwa ngokutya okunencasa, ii-neurons ze-AgRP ziyakhutshwa ukuze kunikwe impendulo efanelekileyo yokondla. Ukongeza, iimpuku ze-AgRP-ablated zibonisa i-anorexia ebangela uxinzelelo kunye nokutya okunencasa-uphawu lokutya okuthuthuzelayo. Ezi ziphumo zibonisa ukuba, xa umsebenzi we-AgRP neuron uphazamisekile, iisekethe ze-neural ezibuthathaka kwiimvakalelo kunye noxinzelelo ziyabandakanyeka kwaye zimodareyithwe kukuthanda ukutya kunye nokubonakaliswa kwe-dopamine.
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