Histamine axons originate from a single source, the tuberomamillary nucleus (TMN) of the posterior hypothalamus, to innervate almost all central nervous system (CNS) regions. This feature, a compact cell group with widely distributed fibers, resembles that of other amine systems, such as noradrenaline or serotonin, and is consistent with a function for histamine over a host of physiological processes, including the regulation of the sleep-wake cycle, appetite, endocrine homeostasis, body temperature, pain perception, learning, memory, and emotion. An important question is whether these diverse physiological roles are served by different histamine neuronal subpopulation. While the histamine system is generally regarded as one single functional unit that provides histamine throughout the brain, evidence is beginning to accumulate in favor of heterogeneity of histamine neurons. The aim of this review is to summarize experimental evidence demonstrating that histamine neurons are heterogeneous, organized into functionally distinct circuits, impinging on different brain regions, and displaying selective control mechanisms. This could imply independent functions of subsets of histamine neurons according to their respective origin and terminal projections.
Keywords: c-fos, GABAA-R, GABA, histamine, H3-R antagonist, stress
Citation: Blandina P, Munari L, Provensi G, and Passani MB (2012) Histamine neurons in the tuberomamillary nucleus: a whole center or distinct subpopulations?. Front. Syst. Neurosci. 6:33. doi: 10.3389/fnsys.2012.00033
Received: 01 February 2012; Accepted: 16 April 2012;
Published online: 04 May 2012.
Edited by:Pertti Panula, University of Helsinki, Finland
Reviewed by:Christine E. Collins, Vanderbilt University, USA
Copyright: © 2012 Blandina, Munari, Provensi and Passani. This is an open-access article distributed under the terms of the Creative Commons Attribution Non Commercial License, which permits non-commercial use, distribution, and reproduction in other forums, provided the original authors and source are credited.
*Correspondence: Patrizio Blandina, Dipartimento di Farmacologia Preclinica e Clinica, Universitá degli Studi di Firenze, Viale G. Pieraccini 6, 50139 Firenze, Italy. e-mail: firstname.lastname@example.org