Martin G B, Thiéry J C
I.N.R.A. Station de Physiologie de la Reproduction, Nouzilly, Monnaie, France.
Exp Brain Res. 1987;67(3):469-78. doi: 10.1007/BF00247280.
The relationship between the pulsatile secretion of luteinizing hormone (LH) and multiunit activity (MUA) in the median eminence and retrochiasmatic area (RCh-ME) of the hypothalamus was investigated within 13 conscious, ovariectomized ewes during the anoestrous season. Eight of the ewes had been treated with oestradiol to reduce their LH pulse frequency. To test whether the activity had been recorded from sites involved in the control of GnRH release, we electrically stimulated the sites studied with the recording electrode and used the LH responses to classify the animals retrospectively for analysis of the MUA data. Following stimulation, LH secretion was either stimulated (Group STIM, n = 5 ewes), inhibited (Group INHIB, n = 4) or showed no response (Group NR, n = 4). Statistical analysis of the MUA data revealed that the onset of LH pulses was associated with an increase in cell activity in STIM ewes and a decrease in activity in both Group INHIB and Group NR ewes. Histological examination revealed that the electrodes were located near the midline in Group STIM ewes, but 1.25 or 2 mm lateral of the midline in Groups NR and INHIB, respectively. We concluded that the MUA in the RCh-ME probably reflects the activity of cells with fibres or terminals involved in the control of GnRH release. Activity which increased at the onset of LH pulses was detected in medial areas of the RCh-ME and may reflect the activity of GnRH neurones. The activity which decreased at the onset of LH pulses in lateral areas of the RCh-ME suggests that both stimulatory and inhibitory inputs may be involved in the release of GnRH pulses.
在发情间期，对13只清醒的去卵巢母羊下丘脑正中隆起和视交叉后区域（RCh-ME）中促黄体生成素（LH）的脉冲式分泌与多单位活动（MUA）之间的关系进行了研究。其中8只母羊接受了雌二醇治疗以降低其LH脉冲频率。为了测试记录活动的部位是否参与了促性腺激素释放激素（GnRH）释放的控制，我们用电刺激了记录电极所在的研究部位，并利用LH反应对动物进行回顾性分类，以分析MUA数据。刺激后，LH分泌要么被刺激（刺激组，n = 5只母羊），要么被抑制（抑制组，n = 4只），要么无反应（无反应组，n = 4只）。对MUA数据的统计分析表明，LH脉冲的开始与刺激组母羊细胞活动的增加以及抑制组和无反应组母羊活动的减少有关。组织学检查显示，电极在刺激组母羊中位于中线附近，但在无反应组和抑制组中分别位于中线外侧1.25或2毫米处。我们得出结论，RCh-ME中的MUA可能反映了具有参与GnRH释放控制的纤维或终末的细胞的活动。在RCh-ME的内侧区域检测到在LH脉冲开始时增加的活动，这可能反映了GnRH神经元的活动。RCh-ME外侧区域在LH脉冲开始时减少的活动表明，刺激性和抑制性输入可能都参与了GnRH脉冲的释放。
