Biochemical and behavioral alterations in developing rats treated with 5,7-dihydroxytryptamine.
Intracisternal administration of 5,7-dihydroxytryptamine (5,7-DHT) to immature rats produced a marked reduction of brain norepinephrine and serotonin. Accompanying these reductions of brain amines were a decrease in body weight and alterations in behavior. After treatment with 5,7-DHT at 3 days of age, locomotor activity was significantly elevated at 14 days of age, but was reduced at 28 days of age. 5,7-DHT alone also induced a significant deficit in acquisition of the shuttle-box avoidance response and blocked body movements observed after decapitation. Treatment with either pargyline or desipramine before injection of 5,7-DHT eliminated the effect of 5,7-DHT on noradrenergic fibers while enhancing the effects of 5,7-DHT on brain serotonergic fibers. These treatments also minimized the deficits of 5,7-DHT on growth and on acquisition of the avoidance response and reversed the blockade of decapitation convulsions. However, animals pretreated with pargyline or desipramine before they received 5,7-DHT still demonstrated hyperactivity at 14 days of age equivalent to that observed in neonates that received only 5,7-DHT. Furthermore, a behavioral syndrome induced by 30 mg/kg of 5-hydroxytryptamine was markedly potentiated by all of the 5,7-DHT treatments which suggest that serotonin receptors were supersensitive.
D015116:5,7-Dihydroxytryptamine / Q000494:pharmacology*; D006916:5-Hydroxytryptophan / Q000494:pharmacology; D000375:Aging; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D001522:Behavior, Animal / Q000187:drug effects*; D001679:Biogenic Amines / Q000378:metabolism; D001835:Body Weight / Q000187:drug effects; D001923:Brain Chemistry / Q000187:drug effects*; D003891:Desipramine / Q000494:pharmacology; D004102:Dihydroxytryptamines / Q000494:pharmacology*; D004347:Drug Interactions; D005260:Female; D008297:Male; D010293:Pargyline / Q000494:pharmacology; D051381:Rats
D001679:Biogenic Amines; D004102:Dihydroxytryptamines; D015116:5,7-Dihydroxytryptamine; D010293:Pargyline; D006916:5-Hydroxytryptophan; D003891:Desipramine