Efectos de focos epilépticos en la corteza visual de la rata sobre el aprendizaje pasivo de evitación.

Abstract

Using the modification of Bures and Buresova to the Kurts and Pearl methods, the effects of interietal epileptic discharges on a passive avoidance reflex (step through) was analysed. Seventy-seven albino rats were surgically prepared to apply sodium penicillin cristals on the surface of the visual cortex to produce an epileptic focus. The results, were compared with the behavior of 41 surgically prepared but non-epileptic rats (control group). The features of the epileptic discharges and EEG records were noted 10 minutes before and after each exploratory reaction or retention test. The result showed differences in the orienting reaction, and in the inmediate, and delayed retention test be­tween epileptic and non-epileptic rats. Thirty-six rats which learned under the activity of the epileptic focus, were subjected without the activation of the focus to a delayed retention test (24 hours later). This group of animals had a lower retention than the group of epileptic rats that remainded epileptic during this test. The results are discussed on the basis of the electrophysiological, biochemical and pharmacological alteration that penicillin may produce on the central nervous system, interfering; with the labial and stable phases of memory.