Figure 4.

EPSC/IPSC (E/I) ratio reveals nonsignificant reduction in KA compared with PBS infused animals. Top panels show responses of a CA3 pyramidal cell evoked by mossy fiber stimuli (0.033 Hz) in which EPSC (black) and IPSC (red) were collected during baseline recordings at holding potentials of −65 and 0 mv, respectively, from PBS (left) and KA (right) infused animals. Bottom panels present E/I ratio for each cell; the ratio for each of 12 (KA) and 21 (PBS) cells was averaged to obtain the values presented in this figure (KA 0.12 ± 0.03, n = 12) compared with PBS infused animals (0.20 ± 0.04, n = 21), p = 0.14, Student’s t test. Synaptic responses induced by optical stimulation of mossy fibers were obtained in three PBS and three KA-treated animals; electrical stimulation was used in the remainder.