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Migration of young granule cells of the rat olfactory bulb
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~IGRAIION OF YOUNG GRANULE CELLS OF THE RAT OLFACTORY BULB. SACHIKO KAKUTA'. YOUICHI ISHIKAWA'. KIYOSHI KISHI. Ist Department of Anatomy. Tohs Universit 7 School ef ~edlcine. 5-21-16 0mori-nishi. 0ta-ku. Tokyo 143. Japan. To analyze the origin and rate of migration of young granule cells of the olfactory bulb. Wistar rats at postnatal day 5 were given intraperitoneal injection of H'-thymidine (4 pCi / g. b. wt.). Groups of 3 rats were fixed 2 hr. 3 days. 6 days. and 8 days after the injection. Brains were removed, and processed for autoradiography. In addition, the topographic relationship between migrating granule cells and radial glial fibers was examined by immunohistochemical detection of vimentin. Two phases of migration were observed. The first phase was the rostralwards migration of young granule cells inside the subependymal layer; they originated in the subependymal layer around the anterior horn of the lateral ventricle, migrated through the subependymal layer around the olfactory ventricle, and reached to the center of the olfactory bulb. It took 6 days to complete this migration, and rate of migration was at 7.8 pm / hr. Throughout this course, granule cells migrated across vimentin-positive radial glial fibers. The second phase was the radial migration from the subependymal layer to the granular layer of the olfactory bulb where immature granule cells differentiated into mature granule cells . It took around 2 days for this migration. Throughout this course, the granule cells migrated along the radial glial fibers.
EXPRESSION AND FUNCTION OF NEURAL CELL ADHESION MOLECULE L1 GENE IN T H E C E N T R A L NERVOUS SYSTEM. MASAYUKI MIURA r HIROAKI ASOU r KAYOKO ISHII r AND KEIICHI UYEMURA~ Department of P h y s i o l o g y , Keio University School of M e d i c i n e t 35 S h i n a n o m a c h l , ShinJuku-ku. T Q k y o I~Q. J a p a n . We investigated the expression and function of L 1 m o l e c u l e using a specific monoclonal antibody and DNA probes. Dot blot analysis of mRNA revealed the expression of L1 g o n e in t h e e m b r y o n i c II d a y m o u s e brain, a n d it i n c r e a s e d rapidly u p to p o s t n a t a l day 5 and then gradually decreased. We analyzed the function of L1 in r e a g g r e g a t e d cerebellar neuron cultures which were prepared f r o m the p o s t n a t a l m o u s e b r a i n a n d g r o w n in s e r u m - d e f i c i e n t culture medium. In 24 hr c u l t u r e s g r o w n on several substrates (laminin, BSA, L1 a n d p o l y L - l y s i n e ) , reaggregated cerebellar neurons exhibited a symmetrical network of l o n g a n d p a r a l l e l neurite processes. In addition, many migrating granular cells were observed o n l y on t h e L1 s u b s t r a t e coated cultures. These results suggest t h a t L1 p o s s e s s e s neuron migrating activity in the developing central nervous system. To investigate the function of L1 in m o r e d e t a i l , we cloned the c D N A of r a t L1 and obtained a 2 . 5 kb c l o n e e n c o d i n g 3'-portion of r a t LI. Homology between rat and m o u s e L1 w a s 9 5 % in the d e d u c e d amino acids sequence. Southern blot analysis of r a t genomic DNA revealed t h a t L1 w a s e n c o d e d in a s i n g l e gene, and a single transcript was detected in t h e b r a i n and several neuroblastoma cell lines, b u t n o t in n o n neuronal c e l l s by N o r t h e r n blot analysis. Although, recent study indicates that NILE is a r a t h o m o l o g u e of LI, o u r s e q u e n c e data was different from NILE. At p r e s e n t , the r e a s o n for t h i s d i s c r e p a n c y is n o t c l e a r .
EXPRESSION OF CELLULAR RETINOIC ACID BINDING PROTEIN (CRABP) AND RETINOIC ACID RECEPTOR (RARB) IN THE HISTOGENESIS OF THE NEURAL TISSUE. TAKANORI YAMAGATA". MAKOTO YAYAKADO 2, MARIKO MOMOI''. TAKASHI MOMOI *s. MASA¥OSIII YANAGISAWA". Departments of 'Pediatrics and 2Anatomy. Jichi Medical school, Minamikawachi-machi. Tochigi.329-O4, Japan. ~Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira. 187 Japan. The expression of CRADP and RAR-B in the histogenesis of the neural tissue was immunohistochemically examined in 10.5 to 12.5-day mouse embryos. CRABP and RAR-~ were expressed on differentiating neuroblasts in the mantle layer of the myeleneephalon and mesencephalon. In lO. 5-day embryos, CRABP was expressed on neuroblasts in the ventral portion of the myelencephalon and the caudal portion of the mesencephalon. In 11.5 to 12.5-day embryos, the distribution of CRABP positive neuroblasts had spread to the dorsal portion of the myelencephalon and to the rostral portion of the mesencephalon. as histogenesis has progressed from ventral to dorsal and caudal to rostral, while CRABP p o s i t i v e n e u r o b l a s t s had disappeared in ventral and caudal portion at the respective level. This indicates that CRABP is expressed in the early phase of neuronal cell differentiation. On the other hand. in lO. 5-day embryos, only a few neuroblasts expressed RAR-~ in the ventral portion of the myelencephalon and the caudal portion of the m e s e n c e p h a l o n . In II.5 to 12.5-day embryos. R A R - ~ was e x p r e s s e d on many neuroblasts in the entire mantle layer. In contrast to CRABP, the expression of RAR-~ r ~ m a i n e d . i n n e u r o b l a s t s a t advanced s t a g e s of h i s t o g e n e s i s .
~IGRAIION OF YOUNG GRANULE CELLS OF THE RAT OLFACTORY BULB. SACHIKO KAKUTA'. YOUICHI ISHIKAWA'. KIYOSHI KISHI. Ist Department of Anatomy. Tohs Universit 7 School ef ~edlcine. 5-21-16 0mori-nishi. 0ta-ku. Tokyo 143. Japan. To analyze the origin and rate of migration of young granule cells of the olfactory bulb. Wistar rats at postnatal day 5 were given intraperitoneal injection of H'-thymidine (4 pCi / g. b. wt.). Groups of 3 rats were fixed 2 hr. 3 days. 6 days. and 8 days after the injection. Brains were removed, and processed for autoradiography. In addition, the topographic relationship between migrating granule cells and radial glial fibers was examined by immunohistochemical detection of vimentin. Two phases of migration were observed. The first phase was the rostralwards migration of young granule cells inside the subependymal layer; they originated in the subependymal layer around the anterior horn of the lateral ventricle, migrated through the subependymal layer around the olfactory ventricle, and reached to the center of the olfactory bulb. It took 6 days to complete this migration, and rate of migration was at 7.8 pm / hr. Throughout this course, granule cells migrated across vimentin-positive radial glial fibers. The second phase was the radial migration from the subependymal layer to the granular layer of the olfactory bulb where immature granule cells differentiated into mature granule cells . It took around 2 days for this migration. Throughout this course, the granule cells migrated along the radial glial fibers.
EXPRESSION AND FUNCTION OF NEURAL CELL ADHESION MOLECULE L1 GENE IN T H E C E N T R A L NERVOUS SYSTEM. MASAYUKI MIURA r HIROAKI ASOU r KAYOKO ISHII r AND KEIICHI UYEMURA~ Department of P h y s i o l o g y , Keio University School of M e d i c i n e t 35 S h i n a n o m a c h l , ShinJuku-ku. T Q k y o I~Q. J a p a n . We investigated the expression and function of L 1 m o l e c u l e using a specific monoclonal antibody and DNA probes. Dot blot analysis of mRNA revealed the expression of L1 g o n e in t h e e m b r y o n i c II d a y m o u s e brain, a n d it i n c r e a s e d rapidly u p to p o s t n a t a l day 5 and then gradually decreased. We analyzed the function of L1 in r e a g g r e g a t e d cerebellar neuron cultures which were prepared f r o m the p o s t n a t a l m o u s e b r a i n a n d g r o w n in s e r u m - d e f i c i e n t culture medium. In 24 hr c u l t u r e s g r o w n on several substrates (laminin, BSA, L1 a n d p o l y L - l y s i n e ) , reaggregated cerebellar neurons exhibited a symmetrical network of l o n g a n d p a r a l l e l neurite processes. In addition, many migrating granular cells were observed o n l y on t h e L1 s u b s t r a t e coated cultures. These results suggest t h a t L1 p o s s e s s e s neuron migrating activity in the developing central nervous system. To investigate the function of L1 in m o r e d e t a i l , we cloned the c D N A of r a t L1 and obtained a 2 . 5 kb c l o n e e n c o d i n g 3'-portion of r a t LI. Homology between rat and m o u s e L1 w a s 9 5 % in the d e d u c e d amino acids sequence. Southern blot analysis of r a t genomic DNA revealed t h a t L1 w a s e n c o d e d in a s i n g l e gene, and a single transcript was detected in t h e b r a i n and several neuroblastoma cell lines, b u t n o t in n o n neuronal c e l l s by N o r t h e r n blot analysis. Although, recent study indicates that NILE is a r a t h o m o l o g u e of LI, o u r s e q u e n c e data was different from NILE. At p r e s e n t , the r e a s o n for t h i s d i s c r e p a n c y is n o t c l e a r .
EXPRESSION OF CELLULAR RETINOIC ACID BINDING PROTEIN (CRABP) AND RETINOIC ACID RECEPTOR (RARB) IN THE HISTOGENESIS OF THE NEURAL TISSUE. TAKANORI YAMAGATA". MAKOTO YAYAKADO 2, MARIKO MOMOI''. TAKASHI MOMOI *s. MASA¥OSIII YANAGISAWA". Departments of 'Pediatrics and 2Anatomy. Jichi Medical school, Minamikawachi-machi. Tochigi.329-O4, Japan. ~Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira. 187 Japan. The expression of CRADP and RAR-B in the histogenesis of the neural tissue was immunohistochemically examined in 10.5 to 12.5-day mouse embryos. CRABP and RAR-~ were expressed on differentiating neuroblasts in the mantle layer of the myeleneephalon and mesencephalon. In lO. 5-day embryos, CRABP was expressed on neuroblasts in the ventral portion of the myelencephalon and the caudal portion of the mesencephalon. In 11.5 to 12.5-day embryos, the distribution of CRABP positive neuroblasts had spread to the dorsal portion of the myelencephalon and to the rostral portion of the mesencephalon. as histogenesis has progressed from ventral to dorsal and caudal to rostral, while CRABP p o s i t i v e n e u r o b l a s t s had disappeared in ventral and caudal portion at the respective level. This indicates that CRABP is expressed in the early phase of neuronal cell differentiation. On the other hand. in lO. 5-day embryos, only a few neuroblasts expressed RAR-~ in the ventral portion of the myelencephalon and the caudal portion of the m e s e n c e p h a l o n . In II.5 to 12.5-day embryos. R A R - ~ was e x p r e s s e d on many neuroblasts in the entire mantle layer. In contrast to CRABP, the expression of RAR-~ r ~ m a i n e d . i n n e u r o b l a s t s a t advanced s t a g e s of h i s t o g e n e s i s .