Balleine B
Department of Experimental Psychology, University of Cambridge, U.K.
Behav Brain Res. 1991 May 15;43(2):167-74. doi: 10.1016/s0166-4328(05)80067-1.
The effect of acute stress on the acquisition of an instrumental action reinforced by electrical stimulation of the medial prefrontal cortex (MPC) was investigated by exposing rats to either escapable, inescapable or no footshock prior to daily self-stimulation training sessions. Treatment with inescapable footshock did not affect the number of sessions required for acquisition of MPC self-stimulation but did increase the rate of responding over acquisition sessions compared with the no-shock group. When the treatment footshock was escapable, however, both a facilitation in acquisition, as indexed by a reduction in the number of sessions to criterion, and an increase in the rate of MPC self-stimulation was found. These data were interpreted as offering evidence for the operation of a dopaminergic mechanism in the acquisition of MPC self-stimulation. Further, they indicate, contrary to the reported effects of footshock on self-stimulation of other brain areas, that exposure to acute stress has a facilitatory effect on the rate of self stimulation of the MPC.
通过在每日自我刺激训练前让大鼠经历可逃避电击、不可逃避电击或无电击，研究急性应激对由内侧前额叶皮质（MPC）电刺激强化的工具性动作习得的影响。与无电击组相比，不可逃避电击处理并不影响MPC自我刺激习得所需的训练次数，但确实增加了整个习得阶段的反应速率。然而，当处理电击是可逃避时，发现既出现了习得促进作用（以达到标准所需的训练次数减少为指标），又出现了MPC自我刺激速率增加的情况。这些数据被解释为为多巴胺能机制在MPC自我刺激习得中的作用提供了证据。此外，与报道的电击对其他脑区自我刺激的影响相反，这些数据表明暴露于急性应激对MPC自我刺激速率具有促进作用。
