Nagatsuka Y
Nihon Naibunpi Gakkai Zasshi. 1983 Sep 20;59(9):1286-99. doi: 10.1507/endocrine1927.59.9_1286.
It has been said that the frontal lobe neocortex regulates the secretion of pituitary hormones. In the present study, the nerve circuit including the frontal lobe neocortex which is concerned in regulating the secretion of pituitary gonadotropin was studied in the 4-day vaginal cycle of female Wistar rats. Electric stimulation (monophasic pulse wave, 1Hz, 6 approximately 9V) of the dorsal part of the anterior frontal lobe neocortex induced evoked potential in the thalamic dorsomedial nucleus (DM), the basolateral amygdaloid nucleus (basolateral-AMYG), the medial septal nucleus (m-SEPT) and the anterior border of the diagonal band of Broca (DBB). Multiple unit activity (MUA) recorded in the DM, basolateral-AMYG and m-SEPT showed a fluctuation with the estrous cycle in which the minimum level was observed on the day of proestrus and the maximum level was observed on the day of estrus. But MUA did not show a distinct fluctuation with the estrous cycle in the frontal lobe neocortex. A horizontal circular cut of the median region in the forebrain-limbic area including the m-SEPT and the anterior border of the DBB on the day of diestrus II induced vaginal cornification on the following day. Excision of the dorsal region of the anterior frontal lobe neocortex on the day of diestrus II increased the serum concentrations of luteinizing hormone (LH) in the afternoon of that day and induced vaginal cornification on the following day. Electrochemical stimulation (DC 120 microA, 30 sec) of the anterior frontal lobe neocortex just before the critical period of ovulation on the day of proestrus blocked the preovulatory surge of LH. Electrochemical stimulation of the anterior frontal lobe neocortex just after excision of the lateral amygdaloid nucleus (lateral-AMYG) including the basolateral-AMYG did not block the preovulatory surge of LH and ovulation. Electrochemical stimulation of the frontal neocortex after excision of the DM did not block the preovulatory LH surge. Excision of the m-SEPT showed a similar effect, but it had little effect on the blockade of the inhibition of LH secretion induced by electrochemical stimulation of the anterior frontal lobe neocortex. It became clear that the dorsal region of the anterior frontal lobe neocortex has an inhibitory function on the secretion of LH and ovulation through the nerve circuit including the DM, the basolateral-AMYG and the median region of the septal area. Then the anterior frontal lobe neocortex probably participates in the periodical rhythm of LH secretion with the estrous cycle.
据说额叶新皮质调节垂体激素的分泌。在本研究中，在雌性Wistar大鼠4天的阴道周期中，对参与调节垂体促性腺激素分泌的包括额叶新皮质的神经回路进行了研究。对额叶新皮质前额叶背侧部分进行电刺激（单相脉冲波，1Hz，6至9V），可在丘脑背内侧核（DM）、杏仁核基底外侧核（基底外侧-杏仁核）、内侧隔核（m-SEPT）和布洛卡斜带前界（DBB）诱发诱发电位。在DM、基底外侧-杏仁核和m-SEPT记录的多单位活动（MUA）显示出随发情周期的波动，其中在动情前期观察到最低水平，在发情期观察到最高水平。但额叶新皮质中的MUA并未随发情周期表现出明显波动。在动情后期II当天，对包括m-SEPT和DBB前界在内的前脑边缘区正中区域进行水平环形切割，导致次日阴道角化。在动情后期II当天切除前额叶新皮质背侧区域，可使当天下午血清促黄体生成素（LH）浓度升高，并在次日导致阴道角化。在动情前期排卵关键期前，对额叶新皮质进行电化学刺激（直流120微安，30秒）可阻断LH的排卵前激增。在切除包括基底外侧-杏仁核在内的外侧杏仁核（外侧-杏仁核）后，对额叶新皮质进行电化学刺激并未阻断LH的排卵前激增和排卵。切除DM后对额叶新皮质进行电化学刺激并未阻断LH的排卵前激增。切除m-SEPT显示出类似的效果，但对额叶新皮质电化学刺激诱导的LH分泌抑制的阻断作用很小。很明显，前额叶新皮质背侧区域通过包括DM、基底外侧-杏仁核和隔区正中区域的神经回路，对LH分泌和排卵具有抑制作用。因此，前额叶新皮质可能参与了LH分泌随发情周期的周期性节律。
