The lateral septal nucleus (LSN) exerts inhibitory control over lordosis in female rats, but the influence of forebrain structures, such as prelimbic (PL) and infralimbic (IL) regions of the medial prefrontal cortex (mPFC), on LSN activity during sexual receptivity is unknown. We hypothesized that the neural responsivity of these connections may differ depending on sexual receptivity. Gonadally intact female Wistar rats received sequential priming injections of estradiol and progesterone (E2-P4). The presence of lordosis was then confirmed by exposing the female rats to a sexually experienced male rat. Intromission was not allowed. Vaginal smear analyses verified that the rats were in proestrus-estrus of the estrous cycle. The results were compared with a diestrus group, which was verified by vaginal smears and the absence of lordosis. Under ethyl-carbamate anesthesia, single-unit extracellular recordings of the LSN were performed during electrical stimulation of the PL and IL to evaluate possible changes in the responsivity of neural connections. Stimulation of the PL or IL produced a short-latency, brief-duration (paucisynaptic) excitatory response in the LSN, followed by a period of afterhyperpolarization. Responsivity of the PL-LSN pathway was unaffected by E2-P4 priming. The paucisynaptic response of the IL-LSN pathway was significantly greater in the E2-P4-primed group than in the diestrus group, and the afterhyperpolarization response decreased to nearly zero. These findings indicate that the IL exerts inhibitory control over the LSN during diestrus in rats, but this inhibitory control decreases under the action of gonadal steroids, seemingly favoring sexual receptivity.

外侧中隔核（LSN）抑制雌性大鼠的脊柱前凸，但在性接受过程中内侧前额叶皮层（mPFC）的前脑结构（如前缘（PL）和下缘（IL）区）对LSN的影响未知。我们假设这些连接的神经反应能力可能会根据性接受能力而有所不同。完好无损的雌性Wistar大鼠开始接受雌二醇和孕酮（E2-P4）的顺序初免注射。然后通过将雌性大鼠暴露于有性经验的雄性大鼠中来确认前凸的存在。不允许引入。阴道涂片分析证实大鼠处于发情周期的发情前期。将结果与二头肌组进行比较，该组经阴道涂片检查和无脊柱前凸证实。在氨基甲酸乙酯麻醉下，在PL和IL的电刺激过程中对LSN进行了单细胞外记录，以评估神经连接反应性的可能变化。在LSN中，PL或IL的刺激产生了短暂的，短暂的（突触突触）兴奋性应答，随后出现了一段超极化的现象。PL-LSN途径的反应性不受E2-P4启动的影响。E2-P4致敏组的IL-LSN通路的突触反应明显大于二头肌组，并且超极化后的应答降低至几乎为零。这些发现表明，IL在大鼠发情过程中对LSN具有抑制作用，但在性腺类固醇的作用下该抑制作用降低，似乎有利于性接受。