Expression of a cardiac Ca(2+)-release channel isoform in mammalian brain.
Mammalian brain possesses ryanodine-sensitive Ca2+ channels, which in muscle cells mediate rapid Ca2+ release from intracellular stores during excitation-contraction coupling. Analysis of bovine brain ryanodine receptor (RyR) channels suggests specific expression of the cardiac-muscle RyR isoform in mammalian brain. Localization using cardiac-muscle RyR-specific antibodies and antisense RNA revealed that brain RyRs were present in dendrites, cell bodies and terminals of rat forebrain, and highly enriched in the hippocampus. Activity of skeletal-muscle RyR channels is coupled to sarcolemmal voltage sensors, in contrast with cardiac-muscle RyR channels, which are known to be Ca(2+)-induced Ca(2+)-release channels. Thus Ca(2+)-induced Ca2+ release from intracellular stores mediated by brain RyR channels may be a major Ca(2+)-signalling pathway in specific regions of mammalian brain, and hence may play a fundamental role in neuronal Ca2+ homoeostasis.
Lai
F A
FA
MRC National Institute for Medical Research, Mill Hill, London, U.K.
Dent
M
M
Wickenden
C
C
Xu
L
L
Kumari
G
G
Misra
M
M
Lee
H B
HB
Sar
M
M
Meissner
G
G
D000818:Animals; D001921:Brain / Q000378:metabolism*; D015220:Calcium Channels / Q000737:chemistry / Q000378:metabolism*; D002417:Cattle; D002531:Cerebellum / Q000378:metabolism; D004285:Dogs; D015870:Gene Expression; D007158:Immunologic Techniques; D017403:In Situ Hybridization; D015544:Inositol 1,4,5-Trisphosphate / Q000494:pharmacology; D008297:Male; D008854:Microscopy, Electron; D008861:Microsomes / Q000378:metabolism; D008970:Molecular Weight; D009132:Muscles / Q000737:chemistry; D009206:Myocardium / Q000737:chemistry; D012333:RNA, Messenger / Q000235:genetics; D011817:Rabbits; D051381:Rats; D011950:Receptors, Cholinergic / Q000737:chemistry / Q000378:metabolism*; D019837:Ryanodine Receptor Calcium Release Channel
D015220:Calcium Channels; D012333:RNA, Messenger; D011950:Receptors, Cholinergic; D019837:Ryanodine Receptor Calcium Release Channel; D015544:Inositol 1,4,5-Trisphosphate