Fig. 6.

Sodium pentobarbital effects in cortical neurons are blocked by bicuculline. In cortical slices from IBA squirrels (n = 4), mean normalized firing rate in 21 neurons was not altered by a 30-min exposure to bicuculline (100 μM). When bicuculline (100 μM) and pentobarbital sodium (300 μM) were bath applied simultaneously during the next 30 min, spontaneous activity in cortical neurons did not differ from time controls (P > 0.05) and was significantly greater than pentobarbital-treated cortical neurons without bicuculline pretreatment (P < 0.001; see Fig. 2A, solid circles). Error bars indicate means ± SE.