Monoclonal antibodies recognizing regional differences in the optic tectum of Xenopus laevis tadpole

$158 THE DISTRIBUTION OF UNCROSSED RETINAL FIBERS IN THE UNILATERALLY MICROPHTHALMIC RAT. AKIRA TOKUNAGA, SHOEI SUGITA* and KATSUMI OTANI, The T h i r d Department o f Anatomy, School o f Medicine, Chiba U n i v e r s i t y . I - 8 - I Inohana, Chiba 280, Japan. I p s i l a t e r a l r e t i n o f u g a l projection was studied in u n i l a t e r a l microphthalmic r a t s , by means of the o r t h o g r a d e h o r s e r a d i s h p e r o x i d a s e (HRP) method. The mutant albino rats have one v e s t i g i a l and one normally developed eyeball. The former eye lacks c o m p l e t e l y the o p t i c nerve. I0 to 12 ~I o f 50% HRP was injected i n t o the vitreous body of the developed eye. Amounts o f the l a b l e l e d r e t i n a l f i b e r s in the i p s i l a t e r a ] o p t i c t r a c t were much larger than those in the normal. Dense networks o f the l a b e l e d f i b e r s were found i p s i l a t e r a l l y t h r o u g h o u t the v e n t r a l and d o r s a l n u c l e i o f the l a t e r a l g e n i c u l a t e body and the mesencephalic o l i v a r y nucleus. In the i p s i l a t e r a l s u p e r i o r c o l l i c u l u s , l a b e l e d o p t i c f i b e r s were d e n s e l y d i s t r i b u t e d to the e n t i r e depth o f the medial 2/3 of the s u p e r f i c i a l gray and o p t i c layers; while in the l a t e r a l I / 3 o f the s u p e r f i c i a l l a y e r s o f the c o l l i c u l u s , t h e y were p r e s e n t o n l y in the stratum opticum. The i n t r a c o l l i c u l a r d i s t r i b u t i o n p a t t e r n o f the uncrossed r e t i n a l f i b e r s in the u n i l a t e r a l microphthalmia was s i m i l a r to that in adult r a t s from which one eye had been removed a t b i r t h . C o n s i d e r a b l e numbers o f i p s i l a t e r a l p r o j e c t i o n f i b e r s were observed in the medial and dorsal terminal nuclei of the accessory o p t i c system.

MONOCLONAL ANTIBODIES RECOGNIZING REGIONAL DIFFERENCES THE O P T I C T E C T U M OF XENOPUS L A E V I S T A D P O L E

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SHIN TAKAGI*, H A J I M E FUJISAWA, T A K A S H I A M A G A I * # D e p a r t m e n t of Anatomy, # D e p a r t m e n t of M i c r o b i o l o g y , Kyoto Prefectural U n i v e r s i t y of Medicine, Kawaramachi-Hirokoji, kamikyo-ku, Kyoto 602, Japan

Monoclonal antibody(Mab) technique enables us to examine molecular d i v e r s i t y in the nervous system. We injected the optic t e c t u m (OT) f r o m 50 Xenopus laevis tadpoles (stage 51-54) into a B A L B / c mouse. Immune spleen cells w e r e fused w i t h m y e l o m a cells (P3X63Ag8UI), and the culture supernatant of h y b r i d o m a cells w e r e screened by immunofluorescence staining of frozen sections of Xenopus tadpole brain. Mab-A5 stained 8 and 9 laminae of OT; and Mab-B2 stained all p l e x i f o r m layers of OT, e x c e p t 8 and 9 laminae. Mab-A5 a n t i g e n is d e t e c t a b l e in the n u c l e u s of Belonci, the corpus geniculatum t h a l a m i c u m and the basal optic nucleus which are all the targets of the optic nerve. The d o r s o m e d i a l part of t e l e n c e p h a l o n , the h a b e n u l a r n u c l e u s and the h y p o t h a l a m u s are also s t a i n e d w i t h Mab-A5; but the optic nerve is not. As Mab-A5 a n t i g e n is on the cell surface, it might act as a m a r k e r m o l e c u l e of optic n e r v e targets.