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Morphology of astrocytic processes as revealed by golgi high voltage electron microscope stereo-scopy
$85 MORPHOLOGY OF A S T R O C Y T I C P R O C E S S E S AS R E V E A L E D BY G O L G I H I G H V O L T A G E ELECTRON M I C R O S C O P E STEREO-SCOPY. KIYOSHI HAMA, Division of Neuroanatomy, School of Human Sciences, Waseda University, Mikajima, Tokorozawa, Saitama, 359, Japan. M o r p h o l o g y of the astrocytic processes has been studied by high voltage electron m i c r o s c o p e stereoscopy using 5 ~ m thick Golgi preparations. They form a t h r e e - d i m e n s i o n a l sponge-like meshwork in the neuropile and a veillike flat sheet around the neuronal somata in the granule cell layer of c e r e b e l l u m and dentate gyrus. In the m e d u l l a r y reticular nu. and in the spinal cord gray, they form a coarse basket around the neuronal soma in which nerve terminals are encapsulated. Details of the t h r e e - d i m e n s i o n a l r e l a t i o n s h i p between neurons and a s t r o c y t i c processes can be revealed by the a p p l i c a t i o n of Golgi h i g h - v o l t a g e electron m i c r o s c o p e stereoscopy.
STRUCTURES OF AXOSOMATICSYNAPSES ON THE PRINCIPAL NEURON IN THE ANTEROVENTRAL CPCHLEAR NUCLEUS. HDZUMI TATSUOKAI. AND THOMAS S. REESE2, 'Department of Anatomy, School of Medicine, Chiba [~iversity, C h i b a 280, J a p a n .
2Laboratory of Neurobiology,
Synaptic structures of the chinchilla
were e x a m i n e d a f t e r
hrain stem slices. AVCN in s e v e r a l distinguished
NINDS, NIH, B e t h e s d a .
n e u r o n in t h e r o s t r a l
direct
freezing
Synapses in the freeze-substituted
respects.
In s p i t e
in f r e e z e - s u b s t i t u t e d
perfusion-fixed and r e l a t e d
on t h e p r i n c i p a l
terminal.
cytoskeletal
Synaptic
of these differences, vesicles
nucleus(AVCN)
of rapidly
from those
four types of snaptic
excised
in p e r f u s i o n - f i x e d terminal
were
w i t h t h e f o u r well known c h e m i c a l t y p e s o f
were u n i f o r m l y r o u n d , b u t t h e i r
elements near the synaptic
cochlear
and f r e e z e - s u b s t i t u t i o n AVCN d i f f e r e d
AVCN and c o r r e l a t e d
MD 20894. U.S.A.
anteroventral
junction
differed
diameters,
deployment,
in e a c h c h e m i c a l t y p e o f
s y n a p s e . Two t y p e s o f f i l a m e n t o u s c o m p o n e n t s , s h o r t v e r t i c a l p r o j e c t i o n s f r o m t h e p o s t s y n a p t i c membrane a n d t h i n f i l a m e n t s p r o t r u d i n g from t h e s e p r o j e c t i o n s , comprised the basic structure of the postsynaptic specialization, b u t t h e i r s i z e s and d i s t r i b u t i o n differed at each chemical type of terminal. Therefore, freeze-substitution chemically different types of synapses, release, and reception.
g i v e s new i n f o r m a t i o n a b o u t s t r t ~ t u r a l w h i c h may r e f l e c t d i f f e r e n c e s in their
differences between transmitter storage,
IMMUNOHISTOCHEMICAL D E T E C T I O N OF GAP JUNCTIONAL PROTEINS (CONNEXIN 32 AND 43) IN CNS OF WEAKLY ELECTRIC FISH AND RAT. TOSHIHARU YAMAMOTO*, LEONARD MALER*, ELLIOT L__L HERTZBERG*, JUNZO OCHI, AND JAMES I. NAGY*, Dept. o__~_f Physiol. T Univ. of Manitoba, 770 Bannatyne Avenue, Winnipeg, Manitoba, Canada R3E OW3, and Dept. o_ff Anatomy, Shiga Univ. of Med. Sci., Otsu, 520-21 Japan. Polyclonal and m o n o c l o n a l a n t i b o d i e s against gap j u n c t i o n a l proteins were used to determine I m m u n o h i s t o c h e m i c a l l y the distribution and cellular localization of rat connexin 32 and connexin 43 in the CNS of weakly electric fish (Gymnotidae) and rat. In electric fish brain, anti-connexin 32 revealed a heterogeneously d i s t r i b u t e d pattern of p u n c t a t e and fibrous i m m u n o r e a c t i v l t y (IR). By immuno-EM, connexln 32-IR was localized to neuronal and glial gap Junctions in areas where electrotonic coupling b e t w e e n neurons has been well documented. By LM, a wide range in the density of fibrous and fine punctate connexln 32-IR was also observed in rat brain. In addition, large immunoreactlve puncta were seen associated with the somata and proximal d e n d r i t e s of motoneurons. By EM, connexln 32-IR was localized to glial and n e u r o n a l gap Junctions, to synaptie vesicles within a discrete population of axons, and to subsurface cisterns within motoneuronal somata. In rat brain, a n t i b o d i e s against connexln 43 produced only punctate i m m u n o r e a c t l v i t y that was u b i q u i t o u s although h e t e r o g e n e o u s l y distributed. By EM, this immunoreactlvity was l o c a l i z e d to gllal gap j u n c t i o n s and intracellularly within gllal processes.
STRUCTURES OF AXOSOMATICSYNAPSES ON THE PRINCIPAL NEURON IN THE ANTEROVENTRAL CPCHLEAR NUCLEUS. HDZUMI TATSUOKAI. AND THOMAS S. REESE2, 'Department of Anatomy, School of Medicine, Chiba [~iversity, C h i b a 280, J a p a n .
2Laboratory of Neurobiology,
Synaptic structures of the chinchilla
were e x a m i n e d a f t e r
hrain stem slices. AVCN in s e v e r a l distinguished
NINDS, NIH, B e t h e s d a .
n e u r o n in t h e r o s t r a l
direct
freezing
Synapses in the freeze-substituted
respects.
In s p i t e
in f r e e z e - s u b s t i t u t e d
perfusion-fixed and r e l a t e d
on t h e p r i n c i p a l
terminal.
cytoskeletal
Synaptic
of these differences, vesicles
nucleus(AVCN)
of rapidly
from those
four types of snaptic
excised
in p e r f u s i o n - f i x e d terminal
were
w i t h t h e f o u r well known c h e m i c a l t y p e s o f
were u n i f o r m l y r o u n d , b u t t h e i r
elements near the synaptic
cochlear
and f r e e z e - s u b s t i t u t i o n AVCN d i f f e r e d
AVCN and c o r r e l a t e d
MD 20894. U.S.A.
anteroventral
junction
differed
diameters,
deployment,
in e a c h c h e m i c a l t y p e o f
s y n a p s e . Two t y p e s o f f i l a m e n t o u s c o m p o n e n t s , s h o r t v e r t i c a l p r o j e c t i o n s f r o m t h e p o s t s y n a p t i c membrane a n d t h i n f i l a m e n t s p r o t r u d i n g from t h e s e p r o j e c t i o n s , comprised the basic structure of the postsynaptic specialization, b u t t h e i r s i z e s and d i s t r i b u t i o n differed at each chemical type of terminal. Therefore, freeze-substitution chemically different types of synapses, release, and reception.
g i v e s new i n f o r m a t i o n a b o u t s t r t ~ t u r a l w h i c h may r e f l e c t d i f f e r e n c e s in their
differences between transmitter storage,
IMMUNOHISTOCHEMICAL D E T E C T I O N OF GAP JUNCTIONAL PROTEINS (CONNEXIN 32 AND 43) IN CNS OF WEAKLY ELECTRIC FISH AND RAT. TOSHIHARU YAMAMOTO*, LEONARD MALER*, ELLIOT L__L HERTZBERG*, JUNZO OCHI, AND JAMES I. NAGY*, Dept. o__~_f Physiol. T Univ. of Manitoba, 770 Bannatyne Avenue, Winnipeg, Manitoba, Canada R3E OW3, and Dept. o_ff Anatomy, Shiga Univ. of Med. Sci., Otsu, 520-21 Japan. Polyclonal and m o n o c l o n a l a n t i b o d i e s against gap j u n c t i o n a l proteins were used to determine I m m u n o h i s t o c h e m i c a l l y the distribution and cellular localization of rat connexin 32 and connexin 43 in the CNS of weakly electric fish (Gymnotidae) and rat. In electric fish brain, anti-connexin 32 revealed a heterogeneously d i s t r i b u t e d pattern of p u n c t a t e and fibrous i m m u n o r e a c t i v l t y (IR). By immuno-EM, connexln 32-IR was localized to neuronal and glial gap Junctions in areas where electrotonic coupling b e t w e e n neurons has been well documented. By LM, a wide range in the density of fibrous and fine punctate connexln 32-IR was also observed in rat brain. In addition, large immunoreactlve puncta were seen associated with the somata and proximal d e n d r i t e s of motoneurons. By EM, connexln 32-IR was localized to glial and n e u r o n a l gap Junctions, to synaptie vesicles within a discrete population of axons, and to subsurface cisterns within motoneuronal somata. In rat brain, a n t i b o d i e s against connexln 43 produced only punctate i m m u n o r e a c t l v i t y that was u b i q u i t o u s although h e t e r o g e n e o u s l y distributed. By EM, this immunoreactlvity was l o c a l i z e d to gllal gap j u n c t i o n s and intracellularly within gllal processes.