Garcia Isabella, Bhullar Paramjit K, Tepe Burak, Ortiz-Guzman Joshua, Huang Longwen, Herman Alexander M, Chaboub Lesley, Deneen Benjamin, Justice Nicholas J, Arenkiel Benjamin R
Program in Developmental Biology, Baylor College of Medicine, Houston, TX, 77030, USA.
Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, 77030, USA.
Brain Struct Funct. 2016 Jan;221(1):1-20. doi: 10.1007/s00429-014-0888-4. Epub 2014 Sep 16.
Neuropeptides play important physiological functions during distinct behaviors such as arousal, learning, memory, and reproduction. However, the role of local, extrahypothalamic neuropeptide signaling in shaping synapse formation and neuronal plasticity in the brain is not well understood. Here, we characterize the spatiotemporal expression profile of the neuropeptide corticotropin-releasing hormone (CRH) and its receptor CRHR1 in the mouse OB throughout development. We found that CRH-expressing interneurons are present in the external plexiform layer, that its cognate receptor is expressed by granule cells, and show that both CRH and CRHR1 expression enriches in the postnatal period when olfaction becomes important towards olfactory-related behaviors. Further, we provide electrophysiological evidence that CRHR1-expressing granule cells functionally respond to CRH ligand, and that the physiological circuitry of CRHR1 knockout mice is abnormal, leading to impaired olfactory behaviors. Together, these data suggest a physiologically relevant role for local CRH signaling towards shaping the neuronal circuitry within the mouse OB.
神经肽在诸如觉醒、学习、记忆和繁殖等不同行为过程中发挥着重要的生理功能。然而，局部的、下丘脑外神经肽信号在塑造大脑突触形成和神经元可塑性方面的作用尚未得到充分理解。在这里，我们描述了神经肽促肾上腺皮质激素释放激素（CRH）及其受体CRHR1在小鼠嗅球整个发育过程中的时空表达谱。我们发现表达CRH的中间神经元存在于外丛状层，其同源受体由颗粒细胞表达，并表明CRH和CRHR1的表达在出生后时期丰富，此时嗅觉对于嗅觉相关行为变得重要。此外，我们提供了电生理证据，表明表达CRHR1的颗粒细胞在功能上对CRH配体有反应，并且CRHR1基因敲除小鼠的生理回路异常，导致嗅觉行为受损。总之，这些数据表明局部CRH信号在塑造小鼠嗅球内神经元回路方面具有生理相关作用。
