Differential calcium dependence in basal and forskolin-potentiated spontaneous transmitter release in basolateral amygdala neurons

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• 作者：Yuki Miura ; Masamitsu Naka ; Norio Matsuki ; Hiroshi Nomura
• 关键词：Forskolin ; cAMP ; Miniature EPSCs ; Calcium-sensing receptors ; LTP
• 刊名：Neuroscience Letters
• 出版年：2012
• 出版时间：31 October, 2012
• 年：2012
• 卷：529
• 期：1
• 页码：1-6
• 全文大小：652 K

文摘

Action potential-independent transmitter release, or spontaneous release, is postulated to produce multiple postsynaptic effects (e.g., maintenance of dendritic spines and suppression of local dendritic protein synthesis). Potentiation of spontaneous release may contribute to the precise modulation of synaptic function. However, the expression mechanism underlying potentiated spontaneous release remains unclear. In this study, we investigated the involvement of extracellular and intracellular calcium in basal and potentiated spontaneous release. Miniature excitatory postsynaptic currents (mEPSCs) of the basolateral amygdala neurons in acute brain slices were recorded. Forskolin, an adenylate cyclase activator, increased mEPSC frequency, and the increase lasted at least 25 min after washout. Removal of the extracellular calcium decreased mEPSC frequency in both na?ve and forskolin-treated slices. On the other hand, chelation of intracellular calcium by BAPTA-AM decreased mEPSC frequency in na?ve, but not in forskolin-treated slices. A blockade of the calcium-sensing receptor (CaSR) resulted in an increase in mEPSC frequency in forskolin-treated, but not in na?ve slices. These findings indicate that forskolin-induced potentiation is accompanied by changes in the mechanisms underlying Ca²⁺-dependent spontaneous release.