McDonald Neil A, Kuzmiski J Brent, Naderi Nima, Schwab Yannick, Pittman Quentin J
Hotchkiss Brain Institute, Department of Physiology and Biophysics, Faculty of Medicine, University of Calgary, Calgary, AB, Canada.
Prog Brain Res. 2008;170:129-36. doi: 10.1016/S0079-6123(08)00412-3.
The magnocellular neurons of the hypothalamic supraoptic nucleus (SON) are a major source of both systemic and central release of the neurohypophyseal peptides, oxytocin (OXT) and arginine-vasopressin (AVP). Both OXT and AVP are released from the somatodendritic compartment of magnocellular neurons and act within the SON to modulate the electrophysiological function of these cells. Cannabinoids (CBs) affect hormonal output and the SON may represent a neural substrate through which CBs exert specific physiological and behavioural effects. Dynamic modulation of synaptic inputs is a fundamental mechanism through which neuronal output is controlled. Dendritically released OXT acts on autoreceptors to generate endocannabinoids (eCBs) which modify both excitatory and inhibitory inputs to OXT neurons through actions on presynaptic CB receptors. As such, OXT and eCBs cooperate to shape the electrophysiological properties of magnocellular OXT neurons, regulating the physiological function of this nucleus. Further study of eCB signalling in the SON, including its interaction with AVP neurons, promises to extend our understanding of the synaptic regulation of SON physiological function.
下丘脑视上核（SON）的大细胞神经元是神经垂体肽催产素（OXT）和精氨酸加压素（AVP）在全身和中枢释放的主要来源。OXT和AVP均从大细胞神经元的体树突区释放，并在SON内发挥作用，调节这些细胞的电生理功能。大麻素（CBs）会影响激素分泌，而SON可能是CBs发挥特定生理和行为效应的神经基础。突触输入的动态调节是控制神经元输出的基本机制。树突释放的OXT作用于自身受体，产生内源性大麻素（eCBs），后者通过作用于突触前CB受体来改变OXT神经元的兴奋性和抑制性输入。因此，OXT和eCBs共同塑造大细胞OXT神经元的电生理特性，调节该核团的生理功能。对SON中eCB信号传导的进一步研究，包括其与AVP神经元的相互作用，有望扩展我们对SON生理功能突触调节的理解。
