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(Reference retrieved automatically from SciELO through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Effects of nitric oxide on magnocellular neurons of the supraoptic nucleus involve multiple mechanisms

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M.P. da Silva [1] ; P.L. Cedraz-Mercez [1] ; W.A. Varanda [1]
Total Authors: 3
[1] Univ Sao Paulo, Dept Fisiol, Fac Med Ribeirao Preto, BR-14049900 Ribeirao Preto, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Brazilian Journal of Medical and Biological Research; v. 47, n. 2, p. 90-100, 2014-02-00.

Physiological evidence indicates that the supraoptic nucleus (SON) is an important region for integrating information related to homeostasis of body fluids. Located bilaterally to the optic chiasm, this nucleus is composed of magnocellular neurosecretory cells (MNCs) responsible for the synthesis and release of vasopressin and oxytocin to the neurohypophysis. At the cellular level, the control of vasopressin and oxytocin release is directly linked to the firing frequency of MNCs. In general, we can say that the excitability of these cells can be controlled via two distinct mechanisms: 1) the intrinsic membrane properties of the MNCs themselves and 2) synaptic input from circumventricular organs that contain osmosensitive neurons. It has also been demonstrated that MNCs are sensitive to osmotic stimuli in the physiological range. Therefore, the study of their intrinsic membrane properties became imperative to explain the osmosensitivity of MNCs. In addition to this, the discovery that several neurotransmitters and neuropeptides can modulate their electrical activity greatly increased our knowledge about the role played by the MNCs in fluid homeostasis. In particular, nitric oxide (NO) may be an important player in fluid balance homeostasis, because it has been demonstrated that the enzyme responsible for its production has an increased activity following a hypertonic stimulation of the system. At the cellular level, NO has been shown to change the electrical excitability of MNCs. Therefore, in this review, we focus on some important points concerning nitrergic modulation of the neuroendocrine system, particularly the effects of NO on the SON. (AU)

FAPESP's process: 12/01859-2 - Nitric Oxide and Neurotransmission in Magnocellular Neurons of the Rat Supraoptic Nucleus
Grantee:Pedro Leonardo Cedraz Mercez
Support Opportunities: Scholarships in Brazil - Doctorate
FAPESP's process: 12/19750-7 - Nitric oxide as a modulator of electrical activity in magnocellular neurons of the rat supraoptic nucleus
Grantee:Wamberto Antonio Varanda
Support Opportunities: Regular Research Grants