Sensory Gating Analysis in Individuals with Copy Number Variants of CHRNA7

Sensory gating, the brain’s ability to suppress irrelevant stimuli, was studied in 15 subjects with CHRNA7 gene deletions, 16 with gene duplications, and 28 of their siblings.

Pairs of brief tones were repeatedly presented and the brain’s responses to the first (S1) and second (S2) tone in each pair were recorded during baseline in all subjects, and after administration of a placebo and actual medication, respectively in the gene abnormality groups. The amplitude, latency and area under the curve were measured for the P50, N100 and P200 component.

Siblings had smaller P200 amplitudes for S1 than patients, but no gating differences were observed. The P50 amplitude for S2 was smaller after medication than at baseline, and the corresponding gating ratio approached significance.

In conclusion, subjects with CHRNA7 gene abnormalities and their siblings have similar gating ratios, but medication tends to reduce the P50 gating deficit.