Synaptosomal uptake and levels of serotonin in rat brain areas after p-chloroamphetamine or B-9 lesions.

In contrast to the pronounced fall in 5HT levels and synaptosomal uptake caused by p-chloroamphetamine, bilateral lesions of the B-9 cell group caused minimal regional changes, except for 35% decreases in the metathalamus-thalamus. We conclude therefore that the prolonged biochemical effects of p-chloroamphetamine are not due to a selective cytotoxic action on B-9 cells; and that a lateral 5HT pathway, possibly from the B-9 cell group, projects to the metathalamus-thalamus.