Cocaine, in contrast to D-amphetamine, does not cause axonal terminal degeneration in neostriatum and agranular frontal cortex of long-evans rats

Abstract

Continuous three day administration via implanted minipumps of cocaine hydrochloride (50–450 mg/kg/day, sc and 100–250 mg/kg/day, iv) did not produce axonal degeneration in frontal agranular cortex or neostriatum that was detectable by Fink-Heimer silver staining or tyrosine hydroxylase immunolabeling. This is in contrast to the extensive axonal degeneration detectable in these regions following d-amphetamine sulfate (10–60 mg/kg/day) administered following an identical protocol. Doses of cocaine and amphetamine were equated using three measures: 1) weight loss, 2) lethality and 3) behavioral activation. Thus, cocaine resembles other catecholamine reuptake blockers and does not cause the neurodegenerative changes characteristic of other abused drugs that interact with the brain's dopamine systems.