Activity-wheel stress and serotonergic hypersensitivity in rats.
Adult male Wistar rats were subjected to activity wheel stress: unlimited access to an activity wheel for up to twelve days and food for 30 to 60 min each day. Each treated rat was paired with a control, the latter being housed in home cages and given sufficient food to maintain a weight similar to the stressed partner. All rats were previously trained on a variable interval schedule for milk reinforcement. When the activity of the stressed rat increased rapidly then decreased suddenly, the pair was decapitated for biochemical analysis. Levels of the serotonin metabolite, 5-hydroxyindoleacetic acid, decreased by 50%, and the Bmax for ketanserin binding increased by 19% in frontal cortical homogenates from the stressed rats when compared to controls. These data support the concept that stress increases the sensitivity of central serotonin receptors.
Mayeda
A R
AR
Department of Psychiatry, Indiana University School of Medicine, Indianapolis.
Simon
J R
JR
Hingtgen
J N
JN
Hofstetter
J R
JR
Aprison
M H
MH
D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism*; D002908:Chronic Disease; D006897:Hydroxyindoleacetic Acid / Q000032:analysis; D007650:Ketanserin / Q000378:metabolism*; D009043:Motor Activity; D005082:Physical Exertion; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000032:analysis; D012701:Serotonin / Q000378:metabolism* / Q000502:physiology; D013312:Stress, Physiological / Q000378:metabolism*
D011985:Receptors, Serotonin; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D007650:Ketanserin