Hypothalamic mechanism

Ferguson AV, Veale WL, Cooper KE (1984) Changes in the hypothalamic mechanisms involved in the control of body temperature induced by the early thermal environment. Brain Res 290 291-306. 

Hypothalamic osmoreceptors have a threshold of 280 mOsM. Below this value, they are not stimulated and little or no ADH is secreted. Maximal ADH levels occur when plasma osmolarity is about 295 mOsM. Within this range, the regulatory system is very sensitive, with measurable increases in ADH secretion occurring in response to a 1% change in plasma osmolarity. Regulation of ADH secretion is an important mechanism by which a normal plasma osmolarity of 290 mOsM is maintained. 

Li, Y Gao, X. B., Sakurai, T. van den Pol, A. N. (2002). Hypocretin/orexin excites hypocretin neurons via a local glutamate neuron-A potential mechanism for orchestrating the hypothalamic arousal system. Neuron 36, 1169-81. 

Cowley, M. A., Smith, R. G., Diano, S. et al. (2003). The distribution and mechanism of action of ghrelin in the CNS demonstrates a novel hypothalamic circuit regulating energy homeostasis. Neuron 37, 649-61. 

Other activators of the histaminergic system may also be involved in wakefulness. The orexin (i.e. hypocretin) A and B neuropeptides were isolated from rat hypothalamic extracts. A mutation in the orexin-2 receptor gene was found to be associated with canine narcolepsy, and mice lacking the orexin peptide display increases in REM and NREM sleep and a decrease in wakefulness time during the active period of normal rodents. However, the exact role of orexin in physiological sleep and the mechanisms involved have not yet been elucidated. 

Fu L. Y., Acuna-Goycolea C., van den Pol A. N. (2004). Neuropeptide Y inhibits hypocretin/orexin neurons by multiple presynaptic and postsynaptic mechanisms tonic depression of the hypothalamic arousal system. J. Neurosci. 

Reports of the effects of Li+ upon the thyroid gland and its associated hormones are the most abundant of those concerned with the endocrine system. Li+ inhibits thyroid hormone release, leading to reduced levels of circulating hormone, in both psychiatric patients and healthy controls [178]. In consequence of this, a negative feedback mechanism increases the production of pituitary TSH. Li+ also causes an increase in hypothalamic thyroid-releasing hormone (TRH), probably by inhibiting its re-... 

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