DEVELOPMENTAL AND GENETIC INFLUENCES ON THE P50 SENSORY GATING PHENOTYPE

Evoked potentials to pairs of click stimuli were recorded from 127 sub jects ranging in age from 10 to 39 years to examine the developmental course of auditory, sensory gating. The ratio of the amplitude of the second response to that of the first provides a quantitative measure o f auditory sensory gating. Contrary to earlier results, rite distribut ion of P50 ratios was unchanged between children and younger adolescen ts (10-14 years), older adolescents (15-19 years), and adults (20-29 a nd 30-39 years). Included in the sample were 39 adolescent twins, allo wing assessment for possible generic effects underlying the P50 sensor y gating phenotype, by comparison of the similarity of the measure in monozygotic and same-sex dizygotic twin pairs. The monozygotic twins h ad significantly higher similarity for the P50 ratio within each twin pair than the dizygotic twins. These results are consistent with the p resence of genetic influences on the P50 sensory gating phenotype.