Kow L M, Pfaff D W
Exp Brain Res. 1987;67(1):93-9. doi: 10.1007/BF00269457.
Electrical activity of neurons in rat hypothalamic ventromedial nucleus was recorded in tissue slices, to investigate central neural mechanisms underlying reduction of food intake caused by TRH and its metabolite, cyclo(His-Pro) [cHP]. Application of TRH had two actions: stimulation of neuronal activity, which was desensitized on closely repeated applications; and modulation of neuronal responses to neurotransmitters, even in the absence of the stimulatory action. The neuromodulatory but not the direct stimulatory action could also be achieved by cHP. The neuromodulatory action is more likely to be a neural mechanism underlying the inhibition of feeding, while other biological functions, unique to TRH, may depend on direct stimulation. In this way, TRH could achieve different biological results through different modes of action on hypothalamic neurons.
在组织切片中记录大鼠下丘脑腹内侧核神经元的电活动，以研究促甲状腺激素释放激素（TRH）及其代谢产物环（组氨酸-脯氨酸）[cHP]导致食物摄入量减少的中枢神经机制。应用TRH有两种作用：刺激神经元活动，这种刺激在频繁重复应用时会脱敏；调节神经元对神经递质的反应，即使在没有刺激作用的情况下也是如此。cHP也可以实现神经调节作用，但不能实现直接刺激作用。神经调节作用更有可能是抑制进食的神经机制，而TRH特有的其他生物学功能可能依赖于直接刺激。通过这种方式，TRH可以通过对下丘脑神经元的不同作用模式实现不同的生物学结果。
