| Abstract: | Previous results from our laboratory have demonstrated that 3-day-old rats given dopamine (DA)-depleting brain lesions are spared the severe behavioral dysfunctions seen after comparable brain damage in adults. This behavioral sparing is accompanied by a sprouting of serotonin (5-HT)-containing neurons in the striatum. The present results extend these observations by demonstrating that rats given the brain lesions as 15- or 27-day-olds continue to suckle, wean, and grow into adulthood without exhibiting any obvious behavioral dysfunctions, yet striatal 5-HT levels do not increase. Moreover, combined destruction of DA- and 5-HT-containing neurons in 3-day-old rat pups also produced no obvious behavioral dysfunctions. These and other results indicate that increases in striatal 5-HT are not necessary for the behavioral sparing observed after DA-depleting brain lesions in neonatal rats. |
