Role of serotonin in the nicotine-induced depression of the brainstem auditory evoked response.

We have examined the role of serotonergic and/or dopaminergic mechanism in the mediation of the nicotine-induced depression of brainstem auditory evoked responses (BAER) to auditory stimuli. Nicotine produced dose- and time-dependent decreases in BAER amplitude. Administration of serotonin-depleting drugs (reserpine or p-chlorophenylalanine (PCPA), prevented this decrease. Administration of catecholamine-depleting drugs (alpha-methyl-p-tyrosine, disulfiram or Dopa), on the other hand, had no effect. These data thus suggest a role for serotonergic mechanisms in the mediation of nicotine-induced depression of the brainstem auditory pathway.