Changes in adenosine-sensitive and norepinephrine-sensitive cyclic amp systems of rat cerebral cortex with an iron-induced epileptic focus

S45 A STUDY ON ~ I E P~LATED AREAS TO THE CONDITIONED ENOTIONAL RESPONSE BY ~ S OF THE [14C] 2-DG ~ I O D TAKASHI YA}~DORI, KOZO SUGIOKA* and YOSHIHIDE ISHIMOTO e. First Department of Anatomy, Kobe University School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe, 650 Japan. By giving 3 times the conditioned stimuli to animals which had been conditioned 2 days previously with paired 25 times of 25 seconds flicker (CS) and 1 second 150 Vac electric shocks (US), the metabolically activated areas were examined by means of the [14C] 2-Deoxyglueose method. At the same time, controls which were given only conditioned stimuli were prepared. Twelve adult male rats of Wistar strain were used, namely a group of 6 animals for the conditioned emotional response test and another group of 6 for the control experiment. The techniques of 2-DG injection and autoradiography were reported elsewhere. Average densities of unit square (200 pm x 200 pm) of 53 nuclei or cortical areas in the left hemisphere were obtained from the autoradiogram by a computer assisted microphotometer. The optical density ratio implying the relative optical density of each structure to that of the corpus callosum was calculated, and the ratios of the same structure in the 2 groups were compared by t-test. The nucleus and areas which showed a significant increase of 2-DG uptake or a tendency of increased uptake were the caudalmost part of area i0 (P<0.05), nucleus lemnisci lateralis, hippocampal formation and area 18 (P
CHANGES IN ADENOSINE-SENSITIVE AND NOREPINEPHRINE-SENSITIVE CYCLIC AMP SYSTEMS OF RAT CEREBRAL CORTEX WITH AN IRON-INDUCED EPILEPTIC FOCUS. AKIYOSHI MORIWAKI*, YUKIO HATTORI*, HIROMICHI YASUHARA*, NOBUYOSHI NISHIDA* & YASUO HORI Dept. Physiol., Okayama Med. S c h . , 2 - 5 - I S h i k a t a - c h o , O k a y a m a 700.

Univ.

A chronic epileptic focus without generalized convulsions was induced by a microinjection o f F e C I 2 s o l u t i o n i n t o the l e f t f r o n t a l c o r t e x o f t h e rat. The appearance of isolated spikes w a s c o n f i r m e d 8 - 1 0 d a y s (early stage) o r 3 0 - 6 0 d a y s (late stage) a f t e r the i n j e c t i o n , t h e n t h e a n i m a l s w e r e d e c a p i t a t e d . Slices of different cortical areas were prepared from the extirpated cerebrum. T h e r e s p o n s e as a d e n o s i n e - o r n o r e p i n e p h r i n e - e l i c i t e d accumulation of cyclic AMP was compared between frontal areas. T h e c y c l i c A M P r e s p o n s e to a d e n o s i n e w a s g r e a t e r o n t h e s i d e o f dominant spike appearance than the opposite, and was blocked by 8-phenyltheophylline i n t h e e a r l y a n d late s t a g e s . The response to norepinephrine was greater on the side of dominant spike appearance than the opposite in the early stage. However, the relationship was reversed in the late stage. The results of adding =- or P-adrenergic antagonists to slices i n d i c a t e t h a t t h e d i f f e r e n c e i n t h e e a r l y s t a g e w a s d u e to t h e P-adrenergic component and in the late stage due to the = - a d r e n e r g i c c o m p o n e n t o f t h e r e s p o n s e to n o r e p i n e p h r i n e .