- Email: [email protected]
Cerebellotectal projection in the rat: Anterograde and retrograde WGA-HRP study
$76
LOCATIONS AND VISUAL RESPONSES OF RELAY NEURONS OF T E C T O - P O N T O - C E R E B E L L A R PROJECTION IN THE CAT. RYUICHI MATSUZAKI* AND SHIN-ICHI KYUHOU*, Department of Integrative Brain Science~ Faculty of Medicine, Kyoto University~ Kyoto 606, Japan. Stimulation of the superior colliculus (SC) evoked mossy fiber (MF) responses in c e r e b e l l a r vermal iobules VI-VII under p e n t o b a r b i t a l anesthesia (35mg/kg, i.v.). It was revealed by e x t r a c e l l u l a r unitary recording that the MF responses were relayed in the d o r s o l a t e r a l pontine nucleus (dlPN), the processus tegmentosus lateralis (NRTPI) and the medial part of the nucleus reticularis tegmenti pontis (NRTPm). Visual responses of the relay neurons were investigated in the immobilized cats under chloralose anesthesia (80-100mg/kg, i.v.). Some of the relay neurons responded to moving visual stimuli with high velocity (the optimal velocity mostly ranged over 330deg/s). The visual receptive fields were mainly in the c o n t r a l a t e r a l hemifield and included t~e fovea. Receptive field d i m e n s i o n s were large, ranging in size from 513 to 5565deg . Eighty seven percent of the visual responsive neurons showed directinal preferences to m o v i n g - s p o t stimuli. The preferred directions were upward and toward the temporal side for large number of cells. After injection of lidocaine (10%, 0.2-0.4~i) into the SC, the visual responses of the neurons projecting onto the posterior vermis disappeared transiently. Thus, we concluded that the neurons in the dlPN, NRTPI and NRTPm receive visual information about moving objects from the SC and send it to the p o s t e r i o r vermis.
AFFERENT CONNECTIONS OF THE LATERAL LOBE OF THE VALVUIA CEREBELLI IN GOLDFISH. DAI Y A N A O I ~ SATORU WATANABE. AND GENYO MITARAI. D e p a r t m e n t of A e r o s P a c e Phvslolo~v. R e s e a r c h Institul;~ 9[ Environmen tal Medicine. Nagoya Universltv. Na¢ova. 464-01 J a p a n . The afferent c o n n e c t i o n s of t h e l a t e r a l v a l v u l a (LV) of goldfish were i n v e s t i g a t e d by retrograde l a be l i ng w i t h h o r s e r a d i s h peroxidase (HRP). Following HRP injections into the ros t ra l p a r t of t he LV. retrogradely labeled n e u r o n s were found ipsflaterally in the p e n - n u c l e u s of the Edinger-Westphal n u c l e u s , the n u c l e u s lateralis valvulae [NLV]. t he i s t h m l c p r i m a r y s e n s o r y trigeminal n u c l e u s (STN), a n d the rostral portion of t he e m i n e n t i a g r a n u l a r i s (EG). Many labeled n e u r o n s were observed in the c o n t r a l a t e r a l inferior olive (IO). After HRP injections into the c a u d a l p a r t of t he LV. r e t r o g r a d e l y lab eled n e u r o n s were f o u n d i p s i l a t e r a l l y i n t h e n u c l e u s p r e t e c t a l i s c e n t r a l i s (CPN), n u c l e u s p a r a c o m m l s s u m l i s , n u c l e u s i s t h m i (NI]. in addition to the Ipsilateral NLV a n d t he contralateral IO. However, labeled n e u r o n s were not observed in the STN a n d the EG which received afferents from the v e s t i b u l a r a nd lateral llne system. These findings suggest that the LV receives visual i n p u t s from three different p a t h w a y s : 1)retina - pretectal area(CPN) LV, 2)retina - opUc tectum (OT] - NI - LV, 3)retina - OT - nucleus pa rs magnocelluralis of the superficial pre t e c t um - NLV LV. In general, a fish tends to orient its dorsal surface towa~rd the light source a n d the a m o u n t o f b o d y inclination is t h e result of a quantitative weighting of visual i n p u t compared to ve s t i bul a r i nput s . This visually guided r e s p o n s e is called the dorsal light response (DLR). The DLR is abolished after the bilateral extirpation of the valvula cerebelli a n d lesion of the p r e t e c t a l area. On the other h a n d . t h e lesion of the OT did not affect t he DLR. Among t he v i s u o - c e r e b e l l a r connections mentioned above, the CPN. which is the accessory optic nuc l e us , projects to the LV directly, not via the OT. This direct projections to the LV m a y be s u b s t a n t i a l in driving the DLR.
C E R E B E L L O T E C T A L PROJECTION IN THE RAT: A N T E R O G R A D E AND R E T R O G R A D E WGA-HRP ~TUDY. YASUO KURIMOTO*, SABURO KAWAGUCHI, AND M I Y A H I K O MURATA*, Department of Integrative Brain Science, Faculty of Medicine, Kyoto University, Kyoto 606, Japan. The cerebellotectal projection was studied in the rat by anterograde and retrograde labelling with W G A - H R P that was injected into the cerebellar nuclei or the superior colliculus (SC) under sodium pentobarbital anesthesia (35 mg/kg, i.p.). The projection arising mainly from the posterior interpositus nucleus (PIN) a n d l a t e r a l n u c l e u s (LN) a n d p a r t l y f r o m the m e d i a l n u c l e u s (MN) a n d anterior interpositus nucleus (AIN), terminated in the exclusively contralateral SC. The fibers arising from the PIN and MN terminated mainly in the deeper zone of layer IV and in layer VI through the entire rostrocaudal extent of the SC. T h e s e t w o t e r m i n a l b a n d s w e l l c o i n c i d e d w i t h the l a y e r s t h a t c o n t a i n l a r g e stellate neurons, which are known as the origins of the tecto-reticulo-spinal p r o j e c t i o n . T h e f i b e r s a r i s i n g f r o m the LN a n d A I N t e r m i n a t e d m a i n l y in the superficial zone of layer IV of the rostral three-fourths of the SC; this zone is known as the origin of the tecto-pontine projection. In addition, the fibers from the LN terminated d e n s e l y in the deeper zone of layer III through layer VII in the l a t e r a l p o r t i o n of the r o s t r a l h a l f of the SC. T h e p r o j e c t i o n n e u r o n s r e t r o g r a d e l y labelled in the MN were distributed only in its caudal half while those in other nuclei were d i s t r i b u t e d through their entire rostrocaudal extent.
LOCATIONS AND VISUAL RESPONSES OF RELAY NEURONS OF T E C T O - P O N T O - C E R E B E L L A R PROJECTION IN THE CAT. RYUICHI MATSUZAKI* AND SHIN-ICHI KYUHOU*, Department of Integrative Brain Science~ Faculty of Medicine, Kyoto University~ Kyoto 606, Japan. Stimulation of the superior colliculus (SC) evoked mossy fiber (MF) responses in c e r e b e l l a r vermal iobules VI-VII under p e n t o b a r b i t a l anesthesia (35mg/kg, i.v.). It was revealed by e x t r a c e l l u l a r unitary recording that the MF responses were relayed in the d o r s o l a t e r a l pontine nucleus (dlPN), the processus tegmentosus lateralis (NRTPI) and the medial part of the nucleus reticularis tegmenti pontis (NRTPm). Visual responses of the relay neurons were investigated in the immobilized cats under chloralose anesthesia (80-100mg/kg, i.v.). Some of the relay neurons responded to moving visual stimuli with high velocity (the optimal velocity mostly ranged over 330deg/s). The visual receptive fields were mainly in the c o n t r a l a t e r a l hemifield and included t~e fovea. Receptive field d i m e n s i o n s were large, ranging in size from 513 to 5565deg . Eighty seven percent of the visual responsive neurons showed directinal preferences to m o v i n g - s p o t stimuli. The preferred directions were upward and toward the temporal side for large number of cells. After injection of lidocaine (10%, 0.2-0.4~i) into the SC, the visual responses of the neurons projecting onto the posterior vermis disappeared transiently. Thus, we concluded that the neurons in the dlPN, NRTPI and NRTPm receive visual information about moving objects from the SC and send it to the p o s t e r i o r vermis.
AFFERENT CONNECTIONS OF THE LATERAL LOBE OF THE VALVUIA CEREBELLI IN GOLDFISH. DAI Y A N A O I ~ SATORU WATANABE. AND GENYO MITARAI. D e p a r t m e n t of A e r o s P a c e Phvslolo~v. R e s e a r c h Institul;~ 9[ Environmen tal Medicine. Nagoya Universltv. Na¢ova. 464-01 J a p a n . The afferent c o n n e c t i o n s of t h e l a t e r a l v a l v u l a (LV) of goldfish were i n v e s t i g a t e d by retrograde l a be l i ng w i t h h o r s e r a d i s h peroxidase (HRP). Following HRP injections into the ros t ra l p a r t of t he LV. retrogradely labeled n e u r o n s were found ipsflaterally in the p e n - n u c l e u s of the Edinger-Westphal n u c l e u s , the n u c l e u s lateralis valvulae [NLV]. t he i s t h m l c p r i m a r y s e n s o r y trigeminal n u c l e u s (STN), a n d the rostral portion of t he e m i n e n t i a g r a n u l a r i s (EG). Many labeled n e u r o n s were observed in the c o n t r a l a t e r a l inferior olive (IO). After HRP injections into the c a u d a l p a r t of t he LV. r e t r o g r a d e l y lab eled n e u r o n s were f o u n d i p s i l a t e r a l l y i n t h e n u c l e u s p r e t e c t a l i s c e n t r a l i s (CPN), n u c l e u s p a r a c o m m l s s u m l i s , n u c l e u s i s t h m i (NI]. in addition to the Ipsilateral NLV a n d t he contralateral IO. However, labeled n e u r o n s were not observed in the STN a n d the EG which received afferents from the v e s t i b u l a r a nd lateral llne system. These findings suggest that the LV receives visual i n p u t s from three different p a t h w a y s : 1)retina - pretectal area(CPN) LV, 2)retina - opUc tectum (OT] - NI - LV, 3)retina - OT - nucleus pa rs magnocelluralis of the superficial pre t e c t um - NLV LV. In general, a fish tends to orient its dorsal surface towa~rd the light source a n d the a m o u n t o f b o d y inclination is t h e result of a quantitative weighting of visual i n p u t compared to ve s t i bul a r i nput s . This visually guided r e s p o n s e is called the dorsal light response (DLR). The DLR is abolished after the bilateral extirpation of the valvula cerebelli a n d lesion of the p r e t e c t a l area. On the other h a n d . t h e lesion of the OT did not affect t he DLR. Among t he v i s u o - c e r e b e l l a r connections mentioned above, the CPN. which is the accessory optic nuc l e us , projects to the LV directly, not via the OT. This direct projections to the LV m a y be s u b s t a n t i a l in driving the DLR.
C E R E B E L L O T E C T A L PROJECTION IN THE RAT: A N T E R O G R A D E AND R E T R O G R A D E WGA-HRP ~TUDY. YASUO KURIMOTO*, SABURO KAWAGUCHI, AND M I Y A H I K O MURATA*, Department of Integrative Brain Science, Faculty of Medicine, Kyoto University, Kyoto 606, Japan. The cerebellotectal projection was studied in the rat by anterograde and retrograde labelling with W G A - H R P that was injected into the cerebellar nuclei or the superior colliculus (SC) under sodium pentobarbital anesthesia (35 mg/kg, i.p.). The projection arising mainly from the posterior interpositus nucleus (PIN) a n d l a t e r a l n u c l e u s (LN) a n d p a r t l y f r o m the m e d i a l n u c l e u s (MN) a n d anterior interpositus nucleus (AIN), terminated in the exclusively contralateral SC. The fibers arising from the PIN and MN terminated mainly in the deeper zone of layer IV and in layer VI through the entire rostrocaudal extent of the SC. T h e s e t w o t e r m i n a l b a n d s w e l l c o i n c i d e d w i t h the l a y e r s t h a t c o n t a i n l a r g e stellate neurons, which are known as the origins of the tecto-reticulo-spinal p r o j e c t i o n . T h e f i b e r s a r i s i n g f r o m the LN a n d A I N t e r m i n a t e d m a i n l y in the superficial zone of layer IV of the rostral three-fourths of the SC; this zone is known as the origin of the tecto-pontine projection. In addition, the fibers from the LN terminated d e n s e l y in the deeper zone of layer III through layer VII in the l a t e r a l p o r t i o n of the r o s t r a l h a l f of the SC. T h e p r o j e c t i o n n e u r o n s r e t r o g r a d e l y labelled in the MN were distributed only in its caudal half while those in other nuclei were d i s t r i b u t e d through their entire rostrocaudal extent.