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Retinal and collicular origins for substance p immunoreactive fibers in pretectum and thalamus of the rat brain
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RETINAL AND COLLICULAR ORIGINS FOR SUBSTANCE P INMUNOREACTIVE FIBERS IN PRETECTUM AND THALAMUS OF THE RAT BRAIN. JOSE JAVIER HIGUEL-HIDALGO*, ~MIKO SENBA, KOICHI TAKATSUJI, AND NASAYA TOHYANA, Department of Anatomy I I and Neuroscience, Qsaka U n i v e r s i t y Medical School, 4-3-57 Nakanoshima, Kita-ku, Osaka 530, Japan. We studied the d i s t r i b u t i o n of substance P (SP) immunoreactive f i b e r s in the p r e t e e t a l and thalamic r e t i n o r e c i p i e n t nuclei of normal r a t s , r a t s with e l e c t r i c a l l e s i o n s to the s u p e r i o r c o l l i c u l u s (SC) or r a t s with e y e - e n u e l e a t i o n . Lesions r e s t r i c t e d to the s u p e r f i c i a l layers of the SC produced a c l e a r disappearance of SP f i b e r s in the dorsal and ventral l a t e r a l g e n i c u l a t e nuclei (DLGN, VLGN) and a reduction in the nucleus of the o p t i c t r a c t (NOT) and l a t e r a l p o s t e r i o r nucleus (LPN), demonstrating a c o l l i c u l a r o r i g i n f o r SP-I f i b e r s in these n u c l e i . Eyeenucleation produced an obvious decrease in the SP-I f i b e r s localized to the preteetal o l i v a r y nucleus, but no diminution of SP-I f i b e r s was observed in any other r e t i n o r e c i p i e n t nucleus. We also lesioned the o p t i c t r a c t and f o u n d SP-I fibers in the r e t i n a l stump. In a d d i t i o n , r e t i n a l ganglion c e l l s retrogradely labeled with fluorogold injected into the chiasm were a l s o immunoreactive f o r SP. Eye-removal produced, however, a c l e a r c o n t r a l a t e r a l increase in SP-I fibers in the DLGN, NOT and LPN. Lesions to the SC in b i l a t e r a l l y enucleated animals a l s o produced a complete l o s s of SP-I f i b e r s of the DLGN i p s i l a t e r a l to the lesion,
indicating that the retinorecipient nuclei
increased fibers after eye-removal
that appear in are also originated
this and the f r o m t h e SC.
other
EFFECTS OF A NON-NMDA RECEPTOR SELECTIVE ANTAGONIST ON ACTIVITIES OF NEURONS IN TIlE CAT PRIMARY VISUAL CORTEX. t t I R 0 3 1 I C l t I S A T O , Y O S I l I 0 RATA AND TADAIIARU TSUMOTO, D e p a r t m e n t of Neurophyslolo~y, Biomedical Research Center, Osaka University Medical School, K i t a k u , O s a k a , 530 JAPAN. A f u n c t i o n a l r o l e o f non-N31DA r e c e p t o r s in the primary v i s u a l c o r t e x was studied using i o n t o p h o r e s l s of a non-N~IDA r e c e p t o r s e l e c t i v e a n t a g o n i s t , 6 - c y a n o - 7 - n i t r o q u l n o x a l l n e - 2 , 3 - d i o n e(CNQX). Cats were a n e s t h e t i z e d with a gas m i x t u r e of 70 % N20, 30 % 02 and 0.5 % h a l o t h a n e and p a r a l y z e d w l t h flaxedi]. In 43 of 52 c e i l s t e s t e d , v i s u a l responses were s t r o n g l y reduced (more than 75 % reduction In the number of spikes) by CNQX applied with the i n t e n s i t y o f c u r r e n t s w l t h which non-N~IDA r e c e p t o r s were s e l e c t i v e l y blocked. The s t r e n g t h o f CNQX e f f e c t was almost i d e n t i c a l in a l l l a y e r s o f the c o r t e x . There was no c o r r e l a t i o n between the f i r i n g frequency o f c e i l s and the magnitude of CNQX e f f e c t suggesting a lack of a c t i v i t y dependency f o r a c t i v a t i o n o f non-NMDA r e c e p t o r s . These r e s u l t s suggest t h a t v i s u a l responses of c o r t i c a l neurons are mediated a t l e a s t in p a r t through non-NMDA receptors.
SEGREGATED CORTICOSTRIATAL AND CORTICOTECTAL PROJECTIONS OF LATERAL SUPRASYLVIAN CORTEX DEMONSTRATED WITH ANTEROGRADE BIOCYTIN AND RETROGRADE FLUORESCENT TECHNIQUES. MASAO NORITA 1, J,G. MCHAFFIE .2, HIDEAKI SHIMIZU *1, AND B,E, STEIN*21Deparlm~nt of Anatomy and Embryology, Tokyo Metropolitan Institute for Neurosciences, Fuchu, Tokyo 183. Japan and 2Department of Physiolo~,,, Medical ~ollege of Virginia, Richmond, Virginia 23298, USA, The present experiments were an attempt to determine if regions along the lateral suprasylvian cortex (LS), known to send dense visual projections to the superior colliculus (SC), also project to the striatum, and if so, to determine whether corticostriatal and corticotectal axons arise from the same neurons. Injections of the anterog-rade tracer biocytin into the posterior portion of LS resulted in dense label in both ST and SC. In ST, labeled fibers and terminals were found predominantly in the caudal part of the head of the ipsilateral caudate nucleus and the caudal portion of the ipsilateral putamen. These injections also resulted in label predominantly in the superficial and deep laminae of the ipsilateral SC. After paired injections of fluorescent dyes (dextran tetramethylrhodamine and dextran fluorescein) into ST and SC, numerous retrogradely labeled LS neurons were observed in layer V and modest numbers in layer III: the corticostriatal neurons were found in layers III and V whereas corticotectal neurons were seen only in layer V. Although labeled neurons from each injection were intermingled in layer V, very few of them were double-labeled. These data suggest that while ST and SC receive substantial visual inputs from the same conical area, the nature of the information they recewe may be quite different.
RETINAL AND COLLICULAR ORIGINS FOR SUBSTANCE P INMUNOREACTIVE FIBERS IN PRETECTUM AND THALAMUS OF THE RAT BRAIN. JOSE JAVIER HIGUEL-HIDALGO*, ~MIKO SENBA, KOICHI TAKATSUJI, AND NASAYA TOHYANA, Department of Anatomy I I and Neuroscience, Qsaka U n i v e r s i t y Medical School, 4-3-57 Nakanoshima, Kita-ku, Osaka 530, Japan. We studied the d i s t r i b u t i o n of substance P (SP) immunoreactive f i b e r s in the p r e t e e t a l and thalamic r e t i n o r e c i p i e n t nuclei of normal r a t s , r a t s with e l e c t r i c a l l e s i o n s to the s u p e r i o r c o l l i c u l u s (SC) or r a t s with e y e - e n u e l e a t i o n . Lesions r e s t r i c t e d to the s u p e r f i c i a l layers of the SC produced a c l e a r disappearance of SP f i b e r s in the dorsal and ventral l a t e r a l g e n i c u l a t e nuclei (DLGN, VLGN) and a reduction in the nucleus of the o p t i c t r a c t (NOT) and l a t e r a l p o s t e r i o r nucleus (LPN), demonstrating a c o l l i c u l a r o r i g i n f o r SP-I f i b e r s in these n u c l e i . Eyeenucleation produced an obvious decrease in the SP-I f i b e r s localized to the preteetal o l i v a r y nucleus, but no diminution of SP-I f i b e r s was observed in any other r e t i n o r e c i p i e n t nucleus. We also lesioned the o p t i c t r a c t and f o u n d SP-I fibers in the r e t i n a l stump. In a d d i t i o n , r e t i n a l ganglion c e l l s retrogradely labeled with fluorogold injected into the chiasm were a l s o immunoreactive f o r SP. Eye-removal produced, however, a c l e a r c o n t r a l a t e r a l increase in SP-I fibers in the DLGN, NOT and LPN. Lesions to the SC in b i l a t e r a l l y enucleated animals a l s o produced a complete l o s s of SP-I f i b e r s of the DLGN i p s i l a t e r a l to the lesion,
indicating that the retinorecipient nuclei
increased fibers after eye-removal
that appear in are also originated
this and the f r o m t h e SC.
other
EFFECTS OF A NON-NMDA RECEPTOR SELECTIVE ANTAGONIST ON ACTIVITIES OF NEURONS IN TIlE CAT PRIMARY VISUAL CORTEX. t t I R 0 3 1 I C l t I S A T O , Y O S I l I 0 RATA AND TADAIIARU TSUMOTO, D e p a r t m e n t of Neurophyslolo~y, Biomedical Research Center, Osaka University Medical School, K i t a k u , O s a k a , 530 JAPAN. A f u n c t i o n a l r o l e o f non-N31DA r e c e p t o r s in the primary v i s u a l c o r t e x was studied using i o n t o p h o r e s l s of a non-N~IDA r e c e p t o r s e l e c t i v e a n t a g o n i s t , 6 - c y a n o - 7 - n i t r o q u l n o x a l l n e - 2 , 3 - d i o n e(CNQX). Cats were a n e s t h e t i z e d with a gas m i x t u r e of 70 % N20, 30 % 02 and 0.5 % h a l o t h a n e and p a r a l y z e d w l t h flaxedi]. In 43 of 52 c e i l s t e s t e d , v i s u a l responses were s t r o n g l y reduced (more than 75 % reduction In the number of spikes) by CNQX applied with the i n t e n s i t y o f c u r r e n t s w l t h which non-N~IDA r e c e p t o r s were s e l e c t i v e l y blocked. The s t r e n g t h o f CNQX e f f e c t was almost i d e n t i c a l in a l l l a y e r s o f the c o r t e x . There was no c o r r e l a t i o n between the f i r i n g frequency o f c e i l s and the magnitude of CNQX e f f e c t suggesting a lack of a c t i v i t y dependency f o r a c t i v a t i o n o f non-NMDA r e c e p t o r s . These r e s u l t s suggest t h a t v i s u a l responses of c o r t i c a l neurons are mediated a t l e a s t in p a r t through non-NMDA receptors.
SEGREGATED CORTICOSTRIATAL AND CORTICOTECTAL PROJECTIONS OF LATERAL SUPRASYLVIAN CORTEX DEMONSTRATED WITH ANTEROGRADE BIOCYTIN AND RETROGRADE FLUORESCENT TECHNIQUES. MASAO NORITA 1, J,G. MCHAFFIE .2, HIDEAKI SHIMIZU *1, AND B,E, STEIN*21Deparlm~nt of Anatomy and Embryology, Tokyo Metropolitan Institute for Neurosciences, Fuchu, Tokyo 183. Japan and 2Department of Physiolo~,,, Medical ~ollege of Virginia, Richmond, Virginia 23298, USA, The present experiments were an attempt to determine if regions along the lateral suprasylvian cortex (LS), known to send dense visual projections to the superior colliculus (SC), also project to the striatum, and if so, to determine whether corticostriatal and corticotectal axons arise from the same neurons. Injections of the anterog-rade tracer biocytin into the posterior portion of LS resulted in dense label in both ST and SC. In ST, labeled fibers and terminals were found predominantly in the caudal part of the head of the ipsilateral caudate nucleus and the caudal portion of the ipsilateral putamen. These injections also resulted in label predominantly in the superficial and deep laminae of the ipsilateral SC. After paired injections of fluorescent dyes (dextran tetramethylrhodamine and dextran fluorescein) into ST and SC, numerous retrogradely labeled LS neurons were observed in layer V and modest numbers in layer III: the corticostriatal neurons were found in layers III and V whereas corticotectal neurons were seen only in layer V. Although labeled neurons from each injection were intermingled in layer V, very few of them were double-labeled. These data suggest that while ST and SC receive substantial visual inputs from the same conical area, the nature of the information they recewe may be quite different.