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Ionic channels and conductance-based models for hypothalamic neuronal thermosensitivity

Authors :
Martin Wechselberger
Chadwick Wright
Georgia A. Bishop
Jack A. Boulant
Source :
American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 291:R518-R529
Publication Year :
2006
Publisher :
American Physiological Society, 2006.

Abstract

Thermoregulatory responses are partially controlled by the preoptic area and anterior hypothalamus (PO/AH), which contains a mixed population of temperature-sensitive and insensitive neurons. Immunohistochemical procedures identified the extent of various ionic channels in rat PO/AH neurons. These included pacemaker current channels [i.e., hyperpolarization-activated cyclic nucleotide-gated channels (HCN)], background potassium leak channels (TASK-1 and TRAAK), and transient receptor potential channel (TRP) TRPV4. PO/AH neurons showed dense TASK-1 and HCN-2 immunoreactivity and moderate TRAAK and HCN-4 immunoreactivity. In contrast, the neuronal cell bodies did not label for TRPV4, but instead, punctate labeling was observed in traversing axons or their terminal endings. On the basis of these results and previous electrophysiological studies, Hodgkin–Huxley-like models were constructed. These models suggest that most PO/AH neurons have the same types of ionic channels, but different levels of channel expression can explain the inherent properties of the various types of temperature-sensitive and insensitive neurons.

Details

ISSN :
15221490 and 03636119
Volume :
291
Database :
OpenAIRE
Journal :
American Journal of Physiology-Regulatory, Integrative and Comparative Physiology
Accession number :
edsair.doi.dedup.....6da9f3be0064c951782eb86301f00ef4
Full Text :
https://doi.org/10.1152/ajpregu.00039.2006