Incongruent pattern of neurokinin B expression in rat and mouse brains.
The expression patterns of Tac2 and NK3 mRNA and of pep2, the neurokinin B (NKB) precursor protein, were compared in rats and mice. Pep2 immunoreactivity was observed in fibers, terminals, and perikarya in the brains of both species, but the number of NKB-immunoreactive cells was generally smaller in mice than in the corresponding nuclei in rats. Congruent distribution patterns of Tac2 mRNA and NKB were found in many nuclei of the thalamus and hypothalamus (habenula, anterodorsal nucleus, preoptic area, arcuate nucleus, paraventricular nucleus). However, mice expressed Tac2 mRNA neither in the hippocampus nor in the nucleus of the lateral olfactory tract, in contrast to rats. Accordingly, mice showed no NKB in the projection areas of these nuclei, such as the olfactory tubercle, whereas a clear NKB signal was present in rat tissues. Surprisingly, we found nearly identical NK3 mRNA expression patterns in both species, despite the species differences in NKB expression. Thus, although the expression patterns of Tac2 and NKB are similar in rats and mice, noteworthy differences exist. Our results have important implications for the interpretation of behavioral results concerning the NKB/NK3 system in these species.
Duarte
Célia Ribeiro
CR
Molecular Neurobiology, Department of Psychiatry, University of Bonn, Sigmund Freud Strasse 25, 53127 Bonn, Germany.
Schütz
Burkhard
B
Zimmer
Andreas
A
D000595:Amino Acid Sequence; D000679:Amygdala / Q000378:metabolism; D000818:Animals; D000918:Antibody Specificity; D001921:Brain / Q000378:metabolism*; D017403:In Situ Hybridization; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D015287:Neurokinin B / Q000276:immunology / Q000378:metabolism; D009842:Oligopeptides / Q000276:immunology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017386:Sequence Homology, Amino Acid; D015320:Tachykinins / Q000378:metabolism*
D009842:Oligopeptides; C484959:Pep2m peptide; D015320:Tachykinins; D015287:Neurokinin B