Inositol 1,4,5-trisphosphate receptors: immunohistochemical localization to discrete areas of rat central nervous system.
The second messenger inositol 1,4,5-trisphosphate triggers the release of intracellular Ca2+ stores upon binding to the inositol 1,4,5-trisphosphate receptor protein, a calcium channel that has been purified and molecularly cloned. To clarify the roles of inositol 1,4,5-trisphosphate receptor in the central nervous system, we have examined in detail the distribution of inositol 1,4,5-trisphosphate receptors in the rat brain and spinal cord using immunohistochemical methods. Inositol 1,4,5-trisphosphate receptors are present in neuronal cells, fibers and terminals in a wide distribution of areas throughout the central nervous system. These include a number of areas not previously reported, such as the olfactory bulb, thalamic nuclei and dorsal horn of the spinal cord. In addition, we have noted a strikingly high density of inositol 1,4,5-trisphosphate receptors in circumventricular organs and neuroendocrine structures such as the area postrema, choroid plexus, subcommisural organ, pineal gland and pituitary. The distribution of inositol 1,4,5-trisphosphate receptors in discrete structures throughout the central nervous system, including interconnected neuronal systems and neuroendocrine and circumventricular organ structures, presumably reflects the importance of Ca2+ release mediated by the phosphoinositide second messenger system in control of diverse physiological processes.
Johns Hopkins University School of Medicine, Department of Neuroscience, Baltimore, MD 21205.
A H
AH
Sharp
T M
TM
Dawson
C A
CA
Ross
M
M
Fotuhi
R J
RJ
Mourey
S H
SH
Snyder
D000818:Animals; D015153:Blotting, Western; D001923:Brain Chemistry / Q000502:physiology*; D001931:Brain Mapping; D015220:Calcium Channels; D002531:Cerebellum / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D002552:Cerebral Ventricles / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D003051:Cochlea / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D007150:Immunohistochemistry; D053496:Inositol 1,4,5-Trisphosphate Receptors; D008297:Male; D009411:Nerve Endings / Q000378:metabolism; D009412:Nerve Fibers / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D016548:Prosencephalon / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D011817:Rabbits; D051381:Rats; D017207:Rats, Sprague-Dawley; D011956:Receptors, Cell Surface / Q000378:metabolism*; D018160:Receptors, Cytoplasmic and Nuclear; D015290:Second Messenger Systems / Q000502:physiology; D013788:Thalamus / Q000166:cytology / Q000378:metabolism / Q000502:physiology
D015220:Calcium Channels; D053496:Inositol 1,4,5-Trisphosphate Receptors; D011956:Receptors, Cell Surface; D018160:Receptors, Cytoplasmic and Nuclear