Fig. 5.

Synaptic efficacy following MI and ANG II modulators. Synaptic efficacy was determined in neurons from control (n = 28 cells) and MI (n = 39 cells) preparations both with and without chronic treatment with captopril (n = 24 cells without MI, n = 18 cells with MI), losartan (n = 15 cells without MI, n = 18 cells with MI), or CGP 42112A (n = 11 cells without MI, n = 15 cells with MI). Nerve fibers leading to the neurons were stimulated with a 2-s train at increasing frequencies. In healthy animals, the output from neurons was similar with and without drug treatment, producing a maximal output frequency of ∼6–12 Hz. In MI animals, this output frequency was similar, except in MI animals treated with losartan. In losartan-treated MI animals, the neurons showed a significant increase in output frequency as the stimulus frequency increased (*P < 0.01, **P < 0.001 by ANOVA).