Facial stimulation at 1 Hz induced LTD of MLI-PC synaptic transmission under control conditions, but not in the presence of CRF (100 nM). The CRF-abolished MLI-PC LTD was restored by application of a selective CRF-R1 antagonist, BMS-763,534 (200 nM), but it was not restored by application of a selective CRF-R2 antagonist, antisauvagine-30 (200 nM). Blocking cannabinoid type 1 (CB1) receptor abolished the facial stimulation-induced MLI-PC LTD, and revealed a CRF-triggered MLI-PC long-term potentiation (LTP) via CRF-R1. Notably, either inhibition of protein kinase C (PKC) with chelerythrine (5 µM) or depletion of intracellular Ca2+ with cyclopiazonic acid (100 µM), completely prevented CRF-triggered MLI-PC LTP in mouse cerebellar cortex in vivo.
The present results indicated that CRF blocked sensory stimulation-induced opioid-dependent MLI-PC LTD by triggering MLI-PC LTP through CRF-R1/PKC and intracellular Ca2+ signaling pathway in mouse cerebellar cortex. These results suggest that activation of CRF-R1 opposes opioid-mediated cerebellar MLI-PC plasticity in vivo in mice.
在控制条件下,1Hz的面部刺激诱导了MLI-PC突触传递的LTD,但不存在CRF(100nM)。通过应用选择性CRF-R1拮抗剂恢复了CRF废除的MLI-PCLTD,BMS-763,534(200nM),但它并没有通过应用选择性CRF-R2拮抗剂来恢复,antisauvagine-30(200nM)。阻断大麻素1型(CB1)受体消除了面部刺激诱导的MLI-PCLTD,并通过CRF-R1揭示了CRF触发的MLI-PC长期增强(LTP)。值得注意的是,用白屈菜红碱(5µM)抑制蛋白激酶C(PKC)或用环吡嗪酸(100µM)消耗细胞内Ca2,完全阻止CRF触发的MLI-PCLTP在小鼠小脑皮层的体内。
目前的结果表明,CRF通过CRF-R1/PKC和细胞内Ca2信号通路触发MLI-PCLTP,阻断了感觉刺激诱导的阿片依赖性MLI-PCLTD。这些结果表明,CRF-R1的激活在小鼠体内对抗阿片样物质介导的小脑MLI-PC可塑性。