RETURNYonago Acta medica 1991;34:25-36
Changes in Monoamine Metabolites after Electrical Stimulation during Various Seizure Stages of Amygdaloid Kindling in Rats
Yasuyuki Aoyama
Department of Neuro-Psychiatry, Faculty of Medicine, Tottori University, Yonago 683, Japan
The left amygdalae of 50 male Wistar rats were stimulated (200 µA, 60 Hz, 2 s) until they reached the intended kindling stages. Monoamine metabolites were measured in the contralateral amygdala (amygdala group, n=28) and the ipsilateral striatum (striatum group, n=22) by brain dialysis before and after electrical stimulation at different seizure stages. In the amygdala group, the level of 3,4-dihydroxyphenylacetic acid (DOPAC) increased significantly 10 and 20 min after electrical stimulation at kindling stages 0-1 and 2-4, respectively. DOPAC increased significantly only at 20 min in rats of stage 5, but this increase was not as high as that in rats of stage 2-4, despite the existence of a generalized seizure. Homovanillic acid levels did not change significantly, but showed a tendency similar to that of DOPAC. 5-Hydroxyindoleacetic acid did not significantly change at any seizure stage. In the striatum group, there were no significant changes in the monoamine metabolites at any seizure stage. These results suggest that dopaminergic neurotransmission in the contralateral amygdala is closely associated with the course of development of seizures in amygdaloid kindling.
Key words: amygdaloid kindling; brain dialysis; monoamine metabolites; rats