Figure 5.

GABA_A-receptor-mediated modulation of experimental febrile seizures. (A) Diazepam (DZP, 150 μg/kg) reduced the latency to seizure onset in P14 rat pups (P<0.05). There was no statistical difference between 50 μg/kg and saline-injected animals. DZP 2.5 mg/kg completely blocked the seizures. DZP was given intraperitoneally 15 min before hyperthermia (HT) onset. (B) Diazepam given at 150 μg/kg did not affect the baseline breath rate, and HT induced an analogous increase in the breath rate in saline- and diazepam-injected rats (P>0.05). At a higher concentration (2.5 mg/kg), DZP suppressed breathing significantly (P<0.01) and HT caused only a small increase in the breath rate. (C) In slice preparation, DZP (1 μM) potentiated the high-frequency stimulation (40 pulses at 100 Hz, horizontal bar) -evoked GABA_AR-mediated depolarization. Sample trace from a slice from a P14 rat pup where stimulation to the border of stratum radiatum and stratum lacunosum-moleculare was given in the presence of AP5, CNQX and CGP 55845. The bar diagrams summarize the effects of DZP on the duration of the depolarization (time to half-maximum) and the number of action potentials associated with the depolarizing phase. P-values (*P<0.05, **P<0.01 and ***P<0.001) are based on ANOVA, Bonferroni (A, B) or Student’s t-test (C), and error bars denote s.e.m. The number of animals (A, B) or cells (C) is indicated in bar diagrams.