Figure 1.
GABAA receptor blockade with gabazine reduces neuronal responsiveness to a greater extent in SC of normal adult animals or short-term DR (STDR) animals than in SC of long-term DR (LTDR) animals. Data presented as mean ± SEM (A) or as raw data (B) represent the ratio between the number of spikes per single unit, averaged over all visual stimulation trials under control conditions and under gabazine (20 mM, 20 nA) iontophoresis. The increase in neuronal responsiveness under gabazine is significantly lower in the LTDR group than in the other two experimental groups (p < 0.001), suggesting that light deprivation reduces GABAA receptor number and/or effectiveness.