Transfer and interference in amygdaloid kindling in cats.

Examination of the effects of primary site kindling upon the development of secondary site amygdaloid kindling in cats showed that the former exerts powerful positive as well as negative after effects upon the latter. The positive after effect appears to be directed towards establishing a linkage between the secondary site and the Stage 6 generalized convulsive mechanism. The negative after effects were strikingly similar to those observed in animals with forebrain bisection subjected to amygdaloid kindling, suggesting that it is primarily directed towards functional accessibility of the cerebral structures interconnected by the forebrain commissure. The similarity of the findings in animals with anterior neocortical lesions supports such an assumption. The transient nature of the negative after effects was indicated by the development of a 'normal' clinical ictal pattern from the secondary site when it occurred spontaneously. Secondary site kindling exerted similar but less prominent negative after effects when the primary site was re-tested. Stage 6 seizure was elicited upon the first trial, however.