title: Expression of a splice variant of choline acetyltransferase in magnocellular neurons of the tuberomammillary nucleus of rat.
abstract: A splice variant of choline acetyltransferase mRNA has recently been identified in the pterygopalatine ganglion of rat. An antibody against this variant protein (designated pChAT) was demonstrated to immunolabel peripheral cholinergic neurons. In the present study, we investigated the expression of pChAT in rat brain. Amongst the brain regions examined, magnocellular neurons in the tuberomammillary nucleus of the posterior hypothalamus were immunohistochemically labelled with anti-pChAT antibody, whilst no immunolabelling was detected in cholinergic neurons in the basal forebrain or striatum. RT-PCR analysis confirmed the expression of pChAT mRNA in the posterior hypothalamus. The distribution of pChAT-positive neurons in the tuberomammillary nucleus was compared with that of neurons positive for adenosine deaminase, which is contained in all neurons of this nucleus. After colchicine treatment to inhibit axonal transport of enzyme, virtually all pChAT-positive cells contained adenosine deaminase. Conversely, about 85% of adenosine deaminase-positive cells contained pChAT in the ventral area, whilst 19% of adenosine deaminase-positive cells were pChAT-positive in the dorsal area. Long axonal projections of pChAT-positive cells in the tuberomammillary nucleus were shown by retrograde labelling of these cells after injection of cholera-toxin B subunit into the cerebral cortex. This study demonstrates that a splice variant of choline acetyltransferase is expressed in the tuberomammillary nucleus of rat. The results raise the possibility that some of the known diverse projection areas of this nucleus may have a cholinergic component.
authors.affiliation: Molecular Neuroscience Research Center, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, 520-2192, Shiga, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Kanayama
authors.forename: O
authors.initials: O
authors.lastname: Yasuhara
authors.forename: A
authors.initials: A
authors.lastname: Matsuo
authors.forename: I
authors.initials: I
authors.lastname: Tooyama
authors.forename: Y
authors.initials: Y
authors.lastname: Aimi
authors.forename: J-P
authors.initials: JP
authors.lastname: Bellier
authors.forename: J I
authors.initials: JI
authors.lastname: Nagy
authors.forename: K
authors.initials: K
authors.lastname: Fukui
authors.forename: H
authors.initials: H
authors.lastname: Kimura
mesh_terms: D000109:Acetylcholine / Q000378:metabolism*; D000243:Adenosine Deaminase / Q000378:metabolism; D017398:Alternative Splicing / Q000235:genetics; D000818:Animals; D001370:Axonal Transport / Q000187:drug effects / Q000502:physiology; D002540:Cerebral Cortex / Q000166:cytology / Q000201:enzymology; D002772:Cholera Toxin / Q000378:metabolism; D002795:Choline O-Acetyltransferase / Q000235:genetics* / Q000378:metabolism; D002799:Cholinergic Fibers / Q000201:enzymology* / Q000648:ultrastructure; D003078:Colchicine; D004525:Efferent Pathways / Q000166:cytology / Q000201:enzymology*; D005456:Fluorescent Dyes; D007026:Hypothalamic Area, Lateral / Q000166:cytology / Q000201:enzymology*; D007150:Immunohistochemistry; D008297:Male; D009474:Neurons / Q000166:cytology / Q000201:enzymology*; D020033:Protein Isoforms / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats
chemical_list: D005456:Fluorescent Dyes; D020033:Protein Isoforms; D012333:RNA, Messenger; D002772:Cholera Toxin; D002795:Choline O-Acetyltransferase; D000243:Adenosine Deaminase; D000109:Acetylcholine; D003078:Colchicine