电刺激大鼠内侧额叶前皮质对听皮层神经元频率感受野可塑性的调制

本文应用常规电生理学技术，研究电刺激大鼠内侧额叶前皮质（medial prefrontal cortex，mPFC）对初级听皮层神经元频率感受野（receptive field，RF）可塑性的调制。电刺激mPFC，137个听皮层神经元（72．8％）RF可塑性受到影响，其中抑制性调制71个神经元（37．7％），易化性调制66个神经元（35．1％），其余51个神经元（27．2％）不受影响。mPFC的抑制性调制效应表现为，RF的偏移时间延长，恢复时间缩短。相反，mPFC的易化性调制效应表现为，RF的偏移时间缩短，恢复时间延长。电刺激mPFC对RF可塑性的调制与声、电刺激之间的时间间隔有关，最佳时间间隔介于5-30ms之间。结果提示，大鼠mPFC可以调制听皮层神经元的功能活动，可能参与听觉学习记忆过程。

Modulation of frequency receptive field plasticity in rat auditory cortical neurons by electrical stimulation of medial prefrontal cortex

Using conventional electrophysiological technique, we investigated the effects of stimulating the medial prefrontal cortex (mPFC) on plasticity of frequency receptive field (RF) in auditory cortical (AC) neurons in rats. When the mPFC was electrically stimulated, the RF plasticity of 51 (27.2%) neurons was not affected and that of 137 neurons (72.8%) was either inhibited (71 neurons, 37.7%) or facilitated (66 neurons, 35.1%). The modulation of RF plasticity by the stimulation of mPFC was dependent upon the time interval between acoustic and electrical stimuli. The best interval time that produced optimal modulation (inhibition or facilitation) ranged from 5 to 30 ms. The inhibitory modulation of mPFC prolonged RF shifting time and shortened RF recovery time. Conversely, the facilitatory modulation of mPFC shortened RF shifting time and prolonged RF recovery time. Our results suggest that the mPFC may affect the plasticity of functional activity in AC neurons, and also may participate in the process of auditory learning and memory.