Pavcovich L A, Ramirez O A
Departamento de Farmacología, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Argentina.
Brain Res Bull. 1991 Jan;26(1):17-21. doi: 10.1016/0361-9230(91)90186-n.
The animals exposed to inescapable shock (IS) showed a behavioral depression which was assessed by the increased number of escape failures on an avoidance escape test, either 24 or 48 hours after. The number of noradrenergic (NA) spontaneously active cells of locus coeruleus (LC) appear to be increased 24 and 48 h later (IS) compared to control animals. On the other hand the firing rate at 24 and 48 hours was continuously decreased. The dose-response curve to inhibitory effect of clonidine (CLON) on firing rate of locus coeruleus (LC) neurons showed a clear shift to the right. These results are discussed in terms of the subsensitivity of alpha-2 adrenoceptor and a calcium-activated potassium current (IK(Ca)) controlling the firing rate of LC neurons and the increased release of noradrenaline induced by IS 24 or 48 h before.
遭受不可逃避电击（IS）的动物表现出行为抑制，这通过在24小时或48小时后的回避逃避试验中逃避失败次数增加来评估。与对照动物相比，在遭受IS后24小时和48小时，蓝斑（LC）中去甲肾上腺素能（NA）自发活动细胞的数量似乎增加。另一方面，在24小时和48小时时放电率持续降低。可乐定（CLON）对蓝斑（LC）神经元放电率的抑制作用的剂量反应曲线明显右移。根据α-2肾上腺素能受体的敏感性降低以及控制LC神经元放电率的钙激活钾电流（IK(Ca)），以及在24或48小时前IS诱导的去甲肾上腺素释放增加来讨论这些结果。
