Objective:To study the function and regulation of CREB signaling in rat hypothalamic neurons by exogeneous corticotropin-releasing hormone(CRH). Methods:Perifused primary cultures of rat hypothalamic neurons. Intracelluar free Ca2+ concentr ation([Ca2+]i) was assayed at 32℃ by fluorescence analysis

the coverslip was mounted in a Delta Scan spectrofluorimeter(Photon Technology International);and phospho-CREB by western blot. Results:The basal lower intracellular Ca2+ level of perifused primary cultures of rat hypothalamic neurons cultured on coverslipy was markedly increased by CRH

and significantly attenuated by application of nifedipine(Nif) or CP-154526. CRH may cause the increase of phospho-CREB in the neuron of hypothalamus

while CP-154526

Nif can significantly inhibit the production of phospho-CREB. Conclusion: CRH may excite hypothalamic neurons directly suggest that phospho-and[Ca2+]i

suggesting a role of CRH type 1 receptor in the activation of CRH gene expression.