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

In vitro differentiation between oxytocin- and vasopressin-secreting magnocellular neurons requires more than one experimental criterion

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da Silva, M. P. [1] ; Merino, R. M. [1] ; Mecawi, A. S. [2] ; Moraes, D. J. [1] ; Varanda, W. A. [1]
Total Authors: 5
[1] Univ Sao Paulo, Ribeirao Preto Med Sch, Dept Physiol, BR-14049900 Ribeirao Preto - Brazil
[2] Univ Malaysia, Dept Physiol, Fac Med, Bandar - Malaysia
Total Affiliations: 2
Document type: Journal article
Source: Molecular and Cellular Endocrinology; v. 400, n. C, p. 102-111, JAN 15 2015.
Web of Science Citations: 8

The phenotypic differentiation between oxytocin (OT)- and vasopressin (VP)-secreting magnocellular neurosecretory cells (MNCs) from the supraoptic nucleus is relevant to understanding how several physiological and pharmacological challenges affect their electrical activity. Although the firing patterns of OT and VP neurons, both in vivo and in vitro, may appear different from each other, much is assumed about their characteristics. These assumptions make it practically impossible to obtain a confident phenotypic differentiation based exclusively on the firing patterns. The presence of a sustained outward rectifying potassium current (SOR) and/or an inward rectifying hyperpolarization-activated current (IR), which are presumably present in OT neurons and absent in VP neurons, has been used to distinguish between the two types of MNCs in the past. In this study, we aimed to analyze the accuracy of the phenotypic discrimination of MNCs based on the presence of rectifying currents using comparisons with the molecular phenotype of the cells, as determined by single-cell RT-qPCR and immunohistochemistry. Our results demonstrated that the phenotypes classified according to the electrophysiological protocol in brain slices do not match their molecular counterparts because vasopressinergic and intermediate neurons also exhibit both outward and inward rectifying currents. In addition, we also show that MNCs can change the relative proportion of each cell phenotype when the system is challenged by chronic hypertonicity (70% water restriction for 7 days). We conclude that for in vitro preparations, the combination of mRNA detection and immunohistochemistry seems to be preferable when trying to characterize a single MNC phenotype. (C) 2014 Elsevier Ireland Ltd. All rights reserved. (AU)

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 type: Regular Research Grants