Behav Brain Res. 2013 May 16. pii: S0166-4328(13)00283-0. doi: 10.1016/j.bbr.2013.05.012. [Epub ahead of print]
Sotomayor-Zárate R, Renard GM, Araya KA, Carreño P, Fuentealba JA, Andrés ME, Gysling K.
puna
Millennium Science Nucleus in Stress and onāga i vailāʻau, Department of Cell and Molecular Biology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile; Centro de Neurobiología y Plasticidad Cerebral, Departamento de Fisiología, Facultad de Ciencias, Universidad de Valparaíso.
lē faʻatino
The lateral septum (LS) is a brain nucleus associated to stress and drug onāga i vailāʻau. Here we show that dopamine extracellular levels in the lateral septum are under the control of corticotrophin releasing factor (CRF). Reverse dialysis of 1μM stressin-1, a type 1 CRF receptor (CRF-R1) agonist, induced a significant increase of LS dopamine extracellular levels in saline-treated rats that was blocked by the co-perfusion of stressin-1 with CP-154526, a specific CRF-R1 antagonist. Repeated cocaine administration (15mg/kg; twice daily for 14 days) suppressed the increase in LS dopamine extracellular levels induced by CRF-R1 activation. This suppression was observed 24hours, as well as 21 days after withdrawal from repeated cocaine administration.
In addition, depolarization-induced dopamine release in the LS was significantly higher in cocaine- compared to saline-treated rats. Thus, our results show that the activation of CRF-R1 in the LS induces a significant increase in dopamine extracellular levels. Interestingly, repeated cocaine administration induces a long-term suppression of the CRF-R1 mediated dopamine release and a transient increase in dopamine releasability in the LS.
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