Premium
Periodic properties of the histaminergic system of the mouse brain
Author(s) -
Rozov Stanislav V.,
Zant Janneke C.,
Karlstedt Kaj,
PorkkaHeiskanen Tarja,
Panula Pertti
Publication year - 2014
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/ejn.12397
Subject(s) - histaminergic , histidine decarboxylase , histamine , histamine n methyltransferase , endocrinology , wakefulness , medicine , hypothalamus , circadian rhythm , striatum , biology , histamine h3 receptor , chemistry , histidine , enzyme , biochemistry , neuroscience , histamine h2 receptor , dopamine , receptor , electroencephalography , antagonist
Brain histamine is involved in the regulation of the sleep–wake cycle and alertness. Despite the widespread use of the mouse as an experimental model, the periodic properties of major markers of the mouse histaminergic system have not been comprehensively characterized. We analysed the daily levels of histamine and its first metabolite, 1‐methylhistamine, in different brain structures of C 57 BL /6 J and CBA / J mouse strains, and the m RNA level and activity of histidine decarboxylase and histamine‐ N ‐methyltransferase in C 57 BL /6 J mice. In the C 57 BL /6 J strain, histamine release, assessed by in vivo microdialysis, underwent prominent periodic changes. The main period was 24 h peaking during the activity period. Additional 8 h periods were also observed. The release was highly positively correlated with active wakefulness, as shown by electroencephalography. In both mouse strains, tissue histamine levels remained steady for 24 h in all structures except for the hypothalamus of CBA / J mice, where 24‐h periodicity was observed. Brain tissue 1‐methylhistamine levels in both strains reached their maxima in the periods of activity. The m RNA level of histidine decarboxylase in the tuberomamillary nucleus and the activities of histidine decarboxylase and histamine‐ N ‐methyltransferase in the striatum and cortex did not show a 24‐h rhythm, whereas in the hypothalamus the activities of both enzymes had a 12‐h periodicity. These results show that the activities of histamine‐metabolizing enzymes are not under simple direct circadian regulation. The complex and non‐uniform temporal patterns of the histaminergic system of the mouse brain suggest that histamine is strongly involved in the maintenance of active wakefulness.