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Synaptic formation of grafted embryonic locus coeruleus suspension in rat hippocampus
$49 S O M A T O S T ~ T I N m R N A IN R A T D E V E L O P M E N T A L C E R E B E L L U M . SHINOBU INAGAK~ l SADAO S H I O S A K A ~, M I W A K O S E K I T A N I *~, M A S A Y A T O H Y A M A ~ A N D HI---ROSHI TAKAGI--, ' IFi--i-~st Department of A n a t o m y ~ Osaka City University Medical School, I-4-54 Asahimachi, ~beno-ku, Osaka, 545 r ~ D e p a r t m e n t of Neuroanatomy, Biomedical Research Center, and ~2nd Department of Anatomy, Osaka University Medical School, Nakanoshima, Kita-ku, Osaka, 530 Japan. We p r e v i o u s l y i m m u n o h i s t o c h e m i c a l l y described numerous somatostatin (SS)c o n t a i n i n g c e l l s in the c e r e b e l l u m of rat pups. To d e t e r m i n e w h e t h e r SS m R N A ~pears in the d e v e l o p i n g cerebellum, we performed in situ h y b r i d i z a t i o n with a ~S l a b e l e d - o l i g o n u c l e o t i d e using postnatal rats at various stages. At postnatal day I or 2, the cerebellar cortex and medulla contained a high density of labeled cells. In the cortex, labeled cells were present in the developing Purkinje and granular cell layers, while no labeled cells were seen in the external granular cell layer. The l a t e r a l c e r e b e l l a r n u c l e i c o n t a i n e d a s i g n i f i c a n t n u m b e r of labeled cells, while other cerebellar nuclei did not. In the adult, the majority of labeled cells were Golgi cells located in the granular cell layer of all areas of the cerebellum. They were frequently located just beneath the Purkinje cells. H o w e v e r , the l a t e r a l c e r e b e l l a r n u c l e i no l o n g e r c o n t a i n e d l a b e l e d c e l l s in a d u l t s . T h e a p p e a r a n c e of SS m R N A c o i n c i d e s w i t h SS p e p t i d e , w h i c h h a s b e e n described in the previous i m m u n o h i s t o c h e m i c a l studies.
SYNAPTIC FORMATIONOF GRAFTEDEMBRYONICLOCUSCOERULEUSSUSPENSION IN RAT HIPPOCAMPUS. YUZO MURATA.!., AND TAN~HICHI CHIBA2, IOeDartment of Anatomy, SaRa ~edic~l Sqho91, N~beshima, SaRa 8~0-0], Japan, an___dd.2The Third Department of ~natomw, Chib~ University, School of Medicine, Inohana, Ch ba 280, Japan. Transplants of a suspension made from 13- to 15-day-old rat embryonic locus coeruleus resion were implanted i n t o the hippocampal f o r m a t i o n of a d u l t i n t a c t r a t s and r a t s from which the a d r e n e r s i c a f f e r e n t s to the hippocampus had been removed w i t h 6-hydroxydopamine (6-OHDA). The 8ro~'th of new adrenergic axons from the implant in the hippocampus was observed f o r 4-8 months a f t e r sursery by immunohistochemistry w i t h TH or NA a n t i b o d y . Fine a x o n - l i k e f i b e r s (diameter about 0.3Nm) and thick d e n d r i t e - l i k e f i b e r s (diameter about 1 . 3 N m ) , labeled immunohistochemic a l l y , were well developed and spread f a r from the 8 r a f t . By e l e c t r o n microscopy, immunohistochemically labeled a x o n - l i k e f i b e r s had symmetrical synaptic con%acts w i t h n o n - l a b e l e d spines and shafts of dendrites, and labeled d e n d r i t e - l i k e f i b e r s had afferents from non-labeled axon t e r minals at locations f a r from the 8 r a f t s i t e . Those non-labeled axons and dendrites were thousht to o r i g i n a t e from the host brains. There were no apparent differences between the 8rowth of implanted adrenersic neurons into formerly i n t a c t rats and denervated rats with 6-OHDA. These results indicate t h a t implanted embryonic n o r a d r e n e r s i c neurons innervate the host brain and are, reciproc a l l y , innervated by the host brain,
SEROTONIN iNNERVATION IN DEVELOPING VISUAL CORTEX OF RAT. AN IMMUNOHISTOCHEMICAL STUDY. MIDORI NAKAZAWA*, MINEKO FUJIMIYA, HIROSHI KIMURA, AND TOSHIHIRO MAEDA, Departments of O~hthalmology*, Anatomy, ~ i g a University of Medical Science, Tsukinowa-cho, Seta, Otsu-city, 5 2 0 - 2 1 , JAPAN. D ~ o ~ of s-~0t~i~HT~containing n e r v e f i b e r s was i m m u n o h i s t o c h e m i cally s t u d i e d i n t h e v i s u a l c o r t e x o f n o r m a l and b i l a t e r a l l y enucleated rats from postnatal days 1 t o 16. On PD3, 5HT i m m u n o r e a c t i v e f i b e r s w e r e a g g r e g a t e d particularly in the subcortical.plate in a region of the premature visual cortex. On PD7, t h e i m m u n o r e a c t i v e v a r i c o s e f i b e r s began t o i n n e r v a t e t h e l o w e r l a y e r o f the cortical p l a t e ( n e w l y a p p e a r e d l a y e r I V ) , w h i c h s t o o d o u t by a g g r e g a t e d 5HT varicosities. The dense i n n e r v a t i o n in this layer increased both in vertical size and i n d e n s i t y up t o 12 days o l d . On PDI4, i t m o d e r a t e l y d e c r e a s e d i n d e n s i t y , but was s t i l l seen on PDI5. On PDI6, when eyes opened, t h e a g g r e g a t i o n o f v a r i c o s e fibers was no l o n g e r v i s i b l e in layer IV, and, instead, a large number of a s c e n d i n g i m m u n o r e a c t i v e f i b e r s t o w a r d s l a y e r s I I and I I I became more c o n s p i c u o u s , Bilateral enucleation at birth resulted in dissociation 2 days e a r l i e r (PDI4) of 5HT i m m u n o r e a c t i v e dense meshworks f r o m l a y e r IV o f t h e d e v e l o p i n g visual cortex. The p r e s e n t s t u d y p r o v i d e s f u r t h e r e v i d e n c e f o r a p o s s i b l e r o l e o f 5HT a f f e r e n t s in cortical d e v e l o p m e n t , such as m o d u l a t i o n o f s y n a p s e f o r m a t i o n i n g e n i c u l o cortical connection.
SYNAPTIC FORMATIONOF GRAFTEDEMBRYONICLOCUSCOERULEUSSUSPENSION IN RAT HIPPOCAMPUS. YUZO MURATA.!., AND TAN~HICHI CHIBA2, IOeDartment of Anatomy, SaRa ~edic~l Sqho91, N~beshima, SaRa 8~0-0], Japan, an___dd.2The Third Department of ~natomw, Chib~ University, School of Medicine, Inohana, Ch ba 280, Japan. Transplants of a suspension made from 13- to 15-day-old rat embryonic locus coeruleus resion were implanted i n t o the hippocampal f o r m a t i o n of a d u l t i n t a c t r a t s and r a t s from which the a d r e n e r s i c a f f e r e n t s to the hippocampus had been removed w i t h 6-hydroxydopamine (6-OHDA). The 8ro~'th of new adrenergic axons from the implant in the hippocampus was observed f o r 4-8 months a f t e r sursery by immunohistochemistry w i t h TH or NA a n t i b o d y . Fine a x o n - l i k e f i b e r s (diameter about 0.3Nm) and thick d e n d r i t e - l i k e f i b e r s (diameter about 1 . 3 N m ) , labeled immunohistochemic a l l y , were well developed and spread f a r from the 8 r a f t . By e l e c t r o n microscopy, immunohistochemically labeled a x o n - l i k e f i b e r s had symmetrical synaptic con%acts w i t h n o n - l a b e l e d spines and shafts of dendrites, and labeled d e n d r i t e - l i k e f i b e r s had afferents from non-labeled axon t e r minals at locations f a r from the 8 r a f t s i t e . Those non-labeled axons and dendrites were thousht to o r i g i n a t e from the host brains. There were no apparent differences between the 8rowth of implanted adrenersic neurons into formerly i n t a c t rats and denervated rats with 6-OHDA. These results indicate t h a t implanted embryonic n o r a d r e n e r s i c neurons innervate the host brain and are, reciproc a l l y , innervated by the host brain,
SEROTONIN iNNERVATION IN DEVELOPING VISUAL CORTEX OF RAT. AN IMMUNOHISTOCHEMICAL STUDY. MIDORI NAKAZAWA*, MINEKO FUJIMIYA, HIROSHI KIMURA, AND TOSHIHIRO MAEDA, Departments of O~hthalmology*, Anatomy, ~ i g a University of Medical Science, Tsukinowa-cho, Seta, Otsu-city, 5 2 0 - 2 1 , JAPAN. D ~ o ~ of s-~0t~i~HT~containing n e r v e f i b e r s was i m m u n o h i s t o c h e m i cally s t u d i e d i n t h e v i s u a l c o r t e x o f n o r m a l and b i l a t e r a l l y enucleated rats from postnatal days 1 t o 16. On PD3, 5HT i m m u n o r e a c t i v e f i b e r s w e r e a g g r e g a t e d particularly in the subcortical.plate in a region of the premature visual cortex. On PD7, t h e i m m u n o r e a c t i v e v a r i c o s e f i b e r s began t o i n n e r v a t e t h e l o w e r l a y e r o f the cortical p l a t e ( n e w l y a p p e a r e d l a y e r I V ) , w h i c h s t o o d o u t by a g g r e g a t e d 5HT varicosities. The dense i n n e r v a t i o n in this layer increased both in vertical size and i n d e n s i t y up t o 12 days o l d . On PDI4, i t m o d e r a t e l y d e c r e a s e d i n d e n s i t y , but was s t i l l seen on PDI5. On PDI6, when eyes opened, t h e a g g r e g a t i o n o f v a r i c o s e fibers was no l o n g e r v i s i b l e in layer IV, and, instead, a large number of a s c e n d i n g i m m u n o r e a c t i v e f i b e r s t o w a r d s l a y e r s I I and I I I became more c o n s p i c u o u s , Bilateral enucleation at birth resulted in dissociation 2 days e a r l i e r (PDI4) of 5HT i m m u n o r e a c t i v e dense meshworks f r o m l a y e r IV o f t h e d e v e l o p i n g visual cortex. The p r e s e n t s t u d y p r o v i d e s f u r t h e r e v i d e n c e f o r a p o s s i b l e r o l e o f 5HT a f f e r e n t s in cortical d e v e l o p m e n t , such as m o d u l a t i o n o f s y n a p s e f o r m a t i o n i n g e n i c u l o cortical connection.