Repeated Isoflurane Exposures Impair Long-Term Potentiation and Increase Basal GABAergic Activity in the Basolateral Amygdala

Figure 1

Single isoflurane exposure for 1 h had no significant effect on the magnitude of LTP in the BLA. Field potentials were evoked in the BLA by stimulation of the external capsule. (a) and (b) show the time course of the changes in the amplitude of the responses after high-frequency stimulation (HFS), in control rats (black circles) and rats exposed to a single, 1 h long isoflurane anesthesia (open circles), 1 day (a), and 1 week (b) after the exposure. The amplitudes of three responses recorded in each min (stimulation at 0.05 Hz) were averaged, and each data point on the plot is the mean and standard error of these averages, from 9 to 11 slices. Traces over the plots are examples from a control rat and from isoflurane-exposed rats; the superimposed field potentials are a baseline response and a response at 50 to 60 min after HFS (each trace is the average of 10 to 20 sweeps). (c) Group data of the mean amplitudes during the 50 to 60 min time window after HFS, expressed as % of the control (baseline) amplitude. Sample sizes, for the control group, for the 1-day group, and for the 1-week group.

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(b)

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