Abstracts

Rationale: Preictal, interictal and postictal emotional disturbances are commonly observed with complex partial seizures. Possibly, these disorders are a manifestation of forced normalization, the process by which compensatory inhibitory mechanisms contain or restrict the seizure focus from spreading. Some temporal lobe epileptics are observed to have increased mood disorders leading up to their next seizure and feel affective relief thereafter. ‘Fast’ and ‘Slow’ rats were initially bred for differential amygdala-kindling epileptogenesis, where Fast rats needed far fewer electrical stimulations to develop kindled convulsions, so it was of interest to determine if Slow rats expressed altered (increased) emotionality manifested by their prolonged development of kindled seizures compared to Fast rats. Methods: Fast and Slow strains were assessed in the conditioned emotional response (CER) paradigm, elevated plus-maze (EPM), open field and light enhanced acoustic startle. Results: Slow animals showed dramatically increased fear during the conditioning procedure compared to Fast rats, and subsequently, Fast animals extinguished their fear behaviors long before the Slow strain. Fast rats also entered the open arms more often and spent more time in the open arms of the EPM. Furthermore, Slow rats produced a significant increase in startle response to a bright-light, which was not observed in the Fast strain. Conclusions: Conceivably, by selecting for processes that inhibit the spread of kindling, there was a concomitant cull of animals with neural mechanisms associated with mood disturbances explained by forced normalization as expressed in Slow rats.