Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid, 28029, Madrid, Spain.
Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid, 28029, Madrid, Spain.
Neuroscience. 2019 May 15;406:626-636. doi: 10.1016/j.neuroscience.2019.01.059. Epub 2019 Feb 28.
The medial prefrontal cortex (mPFC) has been implicated in novelty detection and attention. We studied the effect of mPFC electrical stimulation on whisker responses recorded in the ventroposterior medial thalamic nucleus (VPM), the posterior thalamic nucleus (POm) and the primary somatosensory (S1) cortex in urethane anesthetized rats. Field potentials and unit recordings were performed in the VPM or POm thalamic nuclei, in S1 cortex, and in the Zona Incerta (ZI). Somatosensory evoked potentials were elicited by whisker deflections. Current pulses were delivered by bipolar stimulating electrodes aimed at the prelimbic (PL) or infralimbic (IL) areas of mPFC. PL train stimulation (50 Hz, 500 ms) induced a facilitation of whisker responses in the VPM nucleus that lasted minutes and a short inhibition in the POm nucleus. IL stimulation induced a facilitation of whisker responses in both VPM and POm nuclei. Facilitation was due to corticofugal projections because it was reduced after S1 cortical inactivation with lidocaine, and by activation of NMDA glutamatergic receptors because it was blocked by APV. Paired stimulation of mPFC and whiskers revealed an inhibitory effect at short intervals (<100 ms), which was mediated by ZI inhibitory neurons since PL stimulation induced response facilitation in the majority of ZI neurons (42%) and muscimol injection into ZI nucleus reduced inhibitory effects, suggesting that the mPFC may inhibit the POm neurons by activation of GABAergic ZI neurons. In conclusion, the mPFC may control the flow of somatosensory information through the thalamus by activation of S1 and ZI neurons.
前额叶皮质内侧区（mPFC）被认为与新奇性检测和注意力有关。我们研究了 mPFC 电刺激对在戊巴比妥钠麻醉大鼠的腹后内侧丘脑核（VPM）、丘脑后核（POm）和初级体感皮层（S1）记录的触须反应的影响。在 VPM 或 POm 丘脑核、S1 皮层和间脑（ZI）中进行了场电位和单位记录。通过触须偏转而产生体感诱发电位。电流脉冲通过双极刺激电极传递，电极靶向 mPFC 的前额叶皮质（PL）或下边缘皮质（IL）区域。PL 串刺激（50Hz，500ms）诱导 VPM 核中的触须反应增强，持续数分钟，并在 POm 核中短暂抑制。IL 刺激诱导 VPM 和 POm 核中的触须反应增强。增强是由于皮质传出投射，因为在 S1 皮层用利多卡因失活后，它减少了，并且由于 NMDA 谷氨酸能受体的激活，因为它被 APV 阻断。mPFC 和触须的成对刺激在短时间间隔（<100ms）显示出抑制作用，这是由 ZI 抑制性神经元介导的，因为 PL 刺激诱导了大多数 ZI 神经元（42%）的反应增强，并且 ZI 核内的 muscimol 注射减少了抑制作用，这表明 mPFC 可能通过激活 GABA 能 ZI 神经元来抑制 POm 神经元。总之，mPFC 可以通过激活 S1 和 ZI 神经元来控制体感信息通过丘脑的流动。
