Young W Scott, Song June
Section on Neural Gene Expression, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, United States.
Front Mol Neurosci. 2020 Mar 18;13:40. doi: 10.3389/fnmol.2020.00040. eCollection 2020.
Oxytocin, acting through the oxytocin receptor (Oxtr) in the periphery, is best known for its roles in regulating parturition and lactation. However, it is also now known to possess a number of important social functions within the central nervous system, including social preference, memory and aggression, that vary to different degrees in different species. The Oxtr is found in both excitatory and inhibitory neurons within the brain and research is focusing on how, for example, activation of the receptor in interneurons can enhance the signal-to-noise of neuronal transmission. It is important to understand which neurons in the mouse dorsal hippocampus might be activated during memory formation. Therefore, we examined the colocalization of transcripts in over 5,000 neurons for Oxtr with those for nine different markers often found in interneurons using hairpin chain reaction hybridization on hippocampal sections. Most pyramidal cell neurons of CA2 and many in the CA3 express Oxtr. Outside of those excitatory neurons, over 90% of Oxtr-expressing neurons co-express glutamic acid decarboxylase-1 (Gad-1) with progressively decreasing numbers of co-expressing cholecystokinin, somatostatin, parvalbumin, neuronal nitric oxide synthase, the serotonin 3a receptor, the vesicular glutamate transporter 3, calbindin 2 (calretinin), and vasoactive intestinal polypeptide neurons. Distributions were analyzed within hippocampal layers and regions as well. These findings indicate that Oxtr activation will modulate the activity of ~30% of the Gad-1 interneurons and the majority of the diverse population of those, mostly, interneuron types specifically examined in the mouse hippocampus.
催产素在外周通过催产素受体（Oxtr）发挥作用，其在调节分娩和泌乳方面的作用最为人熟知。然而，现在也已知它在中枢神经系统中具有许多重要的社会功能，包括社会偏好、记忆和攻击行为，这些功能在不同物种中会有不同程度的差异。Oxtr存在于大脑中的兴奋性和抑制性神经元中，研究重点在于例如中间神经元中该受体的激活如何增强神经元传递的信噪比。了解小鼠背侧海马体中哪些神经元在记忆形成过程中可能被激活很重要。因此，我们使用海马切片上的发夹链反应杂交技术，检查了超过5000个神经元中Oxtr转录本与九种不同标记物（这些标记物常在中间神经元中发现）转录本的共定位情况。CA2区的大多数锥体细胞神经元以及CA3区的许多锥体细胞神经元都表达Oxtr。在这些兴奋性神经元之外，超过90%表达Oxtr的神经元共表达谷氨酸脱羧酶-1（Gad-1），而共表达胆囊收缩素、生长抑素、小白蛋白、神经元型一氧化氮合酶、5-羟色胺3a受体、囊泡谷氨酸转运体3、钙结合蛋白2（钙视网膜蛋白）和血管活性肠肽神经元的数量则逐渐减少。还对海马各层和各区域内的分布进行了分析。这些发现表明，Oxtr的激活将调节约30%的Gad-1中间神经元以及其中大多数在小鼠海马体中专门检查的不同类型中间神经元群体的活动。
