Effects of microgravity on brain neurotransmitter receptors.
Neurotransmitter receptor binding and Na+, K+-ATPase activity were examined in the brains of six rats exposed to 7 days of microgravity during the flight of Spacelab 3. The same variables were examined in a group of six ground control rats. 5-HT1 receptor number in the hippocampus was significantly elevated by exposure to the microgravity environment, and cortical sodium-potassium pump activity was significantly depressed. A marginal depression in dopamine D-2 binding in the striatum was noted. Dopamine and 5-HT binding in a wide variety of other central regions, in addition to GABAA, muscarinic acetylcholine, adenosine A1, and opiate receptor binding, and adrenoceptor binding, was unaffected by microgravity exposure.
Miller
J D
JD
Department of Animal Physiology, University of California, Davis 95616.
McMillen
B A
BA
McConnaughey
M M
MM
Williams
H L
HL
Fuller
C A
CA
D000818:Animals; D001921:Brain / Q000201:enzymology; D001923:Brain Chemistry; D006112:Gravitation; D066298:In Vitro Techniques; D008297:Male; D011869:Radioligand Assay; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000378:metabolism; D017981:Receptors, Neurotransmitter / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
D011954:Receptors, Dopamine; D017981:Receptors, Neurotransmitter; D000254:Sodium-Potassium-Exchanging ATPase