[Effect of the destruction of the basolateral nuclei of the amygdala on the character of the electrical activity of the dorsomedial nucleus of the rat thalamus].

Characteristics of the thalamic dorsomedial nucleus slow and neuronal activity in different periods after the basolateral amygdala destruction were studied in semichronic experiments on anesthetized rats. Periodic spontaneous transformation of neuronal activity in rhythmic bursts and development of burst seizure activity were observed 1.5-2h after the destruction. Seizure activity was characterized by groups of 4-6 acute waves appearing at a frequency of 1.5 +/- 0.3 Hz. A change in the coefficient of correlation between the duration of seizure activity and its frequency was determined. Interference between seizure activity and orthodromic focal potentials caused by stimulation of the periamygdaloid cortex and anterior amygdaloid area was shown. Dorsomedial nucleus neurons with long (up to 1 s) responses in the form of impulse rhythmic bursts or tonic activation correlating with the appearance of rhythmic afterdischarge were described. Seizure activity was most expressed during 3-4 days after the amygdala destruction. A disorder of the dorsomedial nucleus transmitting and integrative function associated with seizure activity is supposed to be one of the mechanisms of the change of adaptive behaviour in amygdalectomized animals.