促性腺激素释放激素(GnRH)的合成和分泌调节季节性生育。在大脑中,GnRH阳性神经元的分布是弥漫性的,阻碍监测其细胞和组织水平变化的努力。这里,我们的目标是评估负责后体内季节性生育调节(SFR)的细胞核中的GnRH免疫反应性,前,母羊发情期基底下丘脑的视前区。我们在下丘脑腹内侧基底神经元中检测到反应产物,神经纤维,非神经元免疫反应体,和弥漫性间隙区域。免疫反应性与主要SFR细胞核在弓形中的分布相关,后交叉,脑室周围,内侧视前,视神经,和前视区。通过独立成分分析密度分割和干涉对比度,我们将GnRH非神经元阳性细胞鉴定为包裹在密集的反应产物光环中的小胶质细胞。这些GnRH阳性的小胶质细胞分布在整个下丘脑腹内侧基底的斑块和行,提示它们在旁分泌或近分泌信号传导中的作用。此外,如离子化钙结合衔接分子1(IBA1)免疫细胞化学所示,GnRH反应产物的分布与小胶质密集反应区重叠。因此,我们的研究结果支持以下观点:GnRH和IBA1免疫细胞化学的联合光密度分析使得活性图谱能够用于监测实验干预后的季节变化.
Gonadotropin releasing hormone (GnRH) synthesis and secretion regulates seasonal fertility. In the brain, the distribution of GnRH-positive neurons is diffuse, hindering efforts to monitor variations in its cellular and tissue levels. Here, we aim at assessing GnRH immunoreactivity in nuclei responsible for seasonal fertility regulation (SFR) within the posterior, anterior, and preoptic areas of the basal hypothalamus during estrous in ewes. We detected reaction products in the ventromedial basal hypothalamus in neurons, nerve fibers, non-neuronal immunoreactive bodies, and diffuse interstitial areas. Immunoreactivity correlated with the distribution of the main SFR nuclei in the arcuate, retrochiasmatic, periventricular, medial preoptic, supraoptic, and preoptic areas. By independent component analysis density segmentation and by interferential contrast, we identified GnRH non-neuronal positive bodies as microglial cells encapsulated within a dense halo of reaction products. These GnRH-positive microglial cells were distributed in patches and rows throughout the basal ventromedial hypothalamus, suggesting their role in paracrine or juxtacrine signaling. Moreover, as shown by ionized calcium-binding adaptor molecule 1 (IBA1) immunocytochemistry, the distribution of GnRH reaction products overlapped with the microglial dense reactive zones. Therefore, our findings support the assertion that a combined densitometric analysis of GnRH and IBA1 immunocytochemistry enables activity mapping for monitoring seasonal changes following experimental interventions.