Chronic forced swim stress of rats increases frontal cortical 5-HT2 receptors and the wet-dog shakes they mediate, but not frontal cortical beta-adrenoceptors.
We studied the effects of chronic forced swim stress on 5-HT2 receptors and beta-adrenoceptors in the rat frontal cortex. The number of 5-HT2 receptors was increased immediately after the last chronic stress, but not after an acute stress. In vivo, the number of wet-dog shakes induced by a 5-HT2 receptor agonist, (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI), was increased 24 h after the last chronic stress. However, the concentrations of 5-HT and 5-hydroxyindole acetic acid (5-HIAA), measured by high pressure liquid chromatography (HPLC), were not altered by this stress. Binding sites for [3H]CGP-12177, i.e., beta-adrenoceptor sites, were unchanged after both the acute and the chronic stress. These results suggest that, in the rat, the chronic forced swim stress increases the number of frontal cortical 5-HT2 receptors and the number of wet-dog shakes mediated by these receptors, while the number of frontal cortical beta-adrenoceptors is not increased by this treatment.
Takao
K
K
Department of Psychiatry and Neurosciences, Hiroshima University School of Medicine, Japan.
Nagatani
T
T
Kitamura
Y
Y
Kawasaki
K
K
Hayakawa
H
H
Yamawaki
S
S
D000662:Amphetamines / Q000494:pharmacology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D005625:Frontal Lobe / Q000737:chemistry* / Q000502:physiology; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D011943:Receptors, Adrenergic, beta / Q000032:analysis*; D011985:Receptors, Serotonin / Q000032:analysis*; D015398:Signal Transduction; D013312:Stress, Physiological / Q000378:metabolism*; D013550:Swimming
D000662:Amphetamines; D011943:Receptors, Adrenergic, beta; D011985:Receptors, Serotonin; C015952:4-iodo-2,5-dimethoxyphenylisopropylamine