Mesolimbic dopaminergic supersensitivity following electrical kindling of the amygdala

Limbic seizures developed in rats following daily electrical stimulation of the basolateral nucleus of the amygdala. Animals were designated as "kindled" after five complete (stage 5) behavioral seizures were observed. A subgroup, designated as "superkindled," received three additional weeks of electrical stimulations. Kindled rats were significantly subsensitive to the stereotypy-inducing effects of apomorphine, a direct dopamine agonist, compared to controls. Superkindled rats were supersensitive to the effects of apomorphine. However, both kindled and superkindled rats demonstrated an increase in 3H-spiperone Bmax values, reflecting dopamine D2-receptor densities, in the nucleus accumbens ipsilateral to the stimulating electrode. The number of interictal spikes recorded from the stimulating amygdaloid electrode during the last week of kindling was correlated with changes in apomorphine sensitivity in individual animals.