Evidence for membrane remodeling in ipsilateral thalamus and amygdala following left amygdala-kindled seizures in awake rats.

We examined regional cerebral metabolic rates for glucose (rCMRglc) and brain incorporation coefficients (k*) of each of three intravenously infused fatty acid radiotracers, [9,10-(3H)]palmitate ([3H]PAM), [1-(14C)]arachidonate ([14C]AA) and [1-(14C)]docosahe-xaenoate ([14C]DHA), in awake rats fully kindled by once-daily electrical stimulation of the left amygdala. Compared with sham-stimulated animals, rCMRglc was increased bilaterally during a seizure, particularly in midbrain-brain stem regions, thalamus and basolateral nucleus of the amygdala. At 24 h and 2 weeks after a seizure, there was no significant change in k* for either [14C]AA or [14C]DHA in any brain region, whereas k* for [3H]PAM at 24 h was increased significantly (by 32-53%) ipsilateral to stimulation in regions of the amygdala and thalamus. Contralateral regions showed no significant change. Two weeks after a seizure, k* for [3H]PAM was increased in the ipsilateral lateral dorsal nucleus of the thalamus. These results argue for membrane remodeling involving phosphatidylcholine in the ipsilateral amygdala and thalamus at the completed phase of amygdala kindling. Remodeling may continue for up to 2 weeks after a seizure during the completed phase.