Histamine is a developmentally highly conserved autacoid found in most vertebrate tissues. Its physiological functions are mediated by four 7-transmembrane G protein-coupled receptors (H1R, H2R, H3R, H4R) that are all targets of pharmacological intervention. The receptors display molecular heterogeneity and constitutive activity. H1R antagonists are long known antiallergic and sedating drugs, w...

Hypothalamic histaminergic tuberomammillary (TM) neurons express nicotinic acetylcholine receptors (nAChRs) with kinetic and pharmacological properties resembling those of highly Ca permeable a7 nAChRs. However, the Ca permeability of TM nAChR channels has not been determined. To directly evaluate the Ca permeability of TM nAChRs, patch-clamp recordings were conducted using non-cultured acutely...

Physiol. Soc.. ESSN: 1548-9221. Visit our website at http://www.the-aps.org/. American Physiological Society, 9650 Rockville Pike, Bethesda MD 20814-3991. ©2011 Int. Union Physiol. Sci./Am. the physiological developments. It is published bimonthly in February, April, June, August, October, and December by (formerly published as News in Physiological Science) publishes brief review articles on m...

Histamine receptors are densely expressed in the mesencephalic trigeminal nucleus (MesV) and trigeminal motor nucleus. However, little is known about the functional roles of neuronal histamine in controlling oral-motor activity. Thus, using the whole-cell recording technique in brainstem slice preparations from Wistar rats aged between postnatal days 7 and 13, we investigated the effects of his...

Hypothalamic histaminergic tuberomammillary (TM) neurons express nicotinic acetylcholine receptors (nAChRs) with kinetic and pharmacological properties resembling those of highly Ca(2+) permeable alpha7 nAChRs. However, the Ca(2+) permeability of TM nAChR channels has not been determined. To directly evaluate the Ca(2+) permeability of TM nAChRs, patch-clamp recordings were conducted using non-...

1. Intracellular recordings were obtained from histaminergic tuberomammillary (TM) neurons of rat hypothalamus in an in vitro slice preparation. The properties of a time- and voltage-dependent inward current activated on hyperpolarization, Ih, were studied by use of the single-electrode voltage-clamp technique. 2. The activation curve of Ih was well fit by a sigmoidal function, with half-maxima...

BACKGROUND The hypothalamic nuclei constitute that part of the corticodiencephalic mechanism that activates, controls and integrates the peripheral, autonomic mechanisms, endocrine activity and many somatic functions. Their full integration into behavior requires the neocortex, in particular the limbic system. PURPOSE An antiserum against histamine was used to reveal the location and time of ...