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Sensory innervations of the genital organs in the female young dogs using retrograde and anterograde axonal transport of WGA-HRP
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SPINDLE POTENTIAL IS NOT R E C E P T O R POTENTIAL FUMIO ITO, NORIAKI FUJITSUKA, M A S A H I R O SOKABE and ATSUSHI YOSHIMURA* Department of Physiology, Nagoya University School of Medicine, Nagoya 466 During stretching of muscle spindles isolated from semitendinosus muscles of the frog, Rana catesbeiana, the spindle potential was recorded from a m y e l i n a t e d segment placed ing~n air-gap. Most of the spindle p o t e n t i a l s were abolished on treatment with Ca ~ -channel without any decrease in the ampli+ .blockers, . . . causing . . tude of the afferent Na -splke. Durlng appllcatlon of the d e p o l a r l z l n g currents between 0.2 and 5 nA, the static component of the spindle potential was reversed and a slight decrease in the transgap impedance and in the amplitude of the Na-sp~kes were observed. In normal Ringer's solution, the amplitudes of afferent Na -spikes and the peak of spindle potential were linearly increased and decreased during application of hyper- a n ~ d e p o l a r i z i n g currents of up to 60 nA respectively, during which the rate of the Na -spikes was n o % modified. These results imply that the spindle potential is mainly due to the Ca ~ t inflow and is independent of the m e c h a n o e l e c t r i c t r a n s d u c t i o n in the muscle spindle. When a spindle receptor is stretched in an isotonic sucrose solution containing 1 mM L-arginine, a small depolarizing potential at the end of the dynamic stretch is followed by a larger hyperpolarization. The h y p ~ r p o l a r i z i n g spindle potential is abolished by K channel blockers. Since the K -channels along the sensory terminal become ~locked, the transgap impedance and the a m p l i t u d e s of the ~pindle potential and Na -spikes are increased. The peak and static rates of Na'-spikes depend on the strength of the imposed polarizing currents of up to 60 hA. These results suggest that in an axonal r e g i o ~ (around the first node) proximal to the encoding site for afferent impulse, K -channels act with both orth~dromic and antidromic d e p o l a r i z i n g currents in normal Ringer's solution. The K -channel activation may contribute to the slow a d a p t a t i o n of the spindle potential elicited by orthodromic depolarization (including a part of the receptor potential), and may also protect misfiring by decreasing the impedance to antidormic d e p o l a r i z i n g currents, as in large muscle action currents.
SENSORY INNERVATIONS OF THE GENITAL ORGANS IN THE FEMALE YOUNG DOGS USING RETROGRADE AND ANTEROGRADE A X O N A L TRANSPORT OF WGA-HRP. MASATOSHI M O R I M O T O ~ ) Y O S H I O T A N I G U T I ~ ) * T A D A H I D E TOTOKI~ )*and TAKESHI KANASEKI~ ) i) Department of Anatomy, Faculty of Medicine, Kyushu University, 3-1-1, Maidashi, Fukuoka, 812, and 2) Department of Anesthesiology, Saga Medical School, Nabeshima, Saga, 840-01, Japan Sensory innervations of the female genital organs (ovary, oviduct, uterine horn, uterine cervix, and vagina) of young dogs were examined using anterograde and retrograde axonal transport of WGA-HRP. For the operation and fixation, the experimental animals were deeply anesthetized. After injections into the left ovary and oviduct, most labeled cells were found in the ipsilateral TI3, L1 and LI,2 dorsal root ganglia (DRGs) respectively. Following injections into the left uterine horn, most labeled cells were observed in the ipsilateral L2,3 and SI-3 DRGs. Injections into these organs resulted in bilateral labeling with most labeled cells occurring in the ipsilateral DRGs. A small number of labeled cells were found in L2 and L3 DRGs after injections into the uterine cervix. Following injections into the wall of the vagina, many labeled cells were observed in L2,3 and SI-3 DRGs. After injections of WGA-HRP into the a b o v e - m e n t i o n e d ganglia, the following conclusions were obtained: In the ovary, many labeled fiber bundles were observed in the medulla, while in the cortex, labeled fibers formed fiber networks and were also seen just beneath the germinal epithelium. In the ampulla and isthmus of the oviduct, many labeled fibers were found in the smooth muscle coats and some labeled fibers were observed in the mucosal folds. In the uterine horn, a large number of labeled fiber bundles were observed in the m e s o m e t r i u m and some of them entered the endometrium through the myometrium. In the uterine cervix, some labeled fiber bundles were observed in the serous membranes and a small number of labeled fibers were seen in the lamina propria and epithelium. In the vagina, many labeled fibers were found in the fibrous adventitia after injections into SI-3 DRGs, and some fibers were seen in the stratified squamous epithelium. Some labeled fibers were seen to be terminated in the e p i t h e l i u m of the oviduct, uterine horn and cervix, and vagina.
SPINDLE POTENTIAL IS NOT R E C E P T O R POTENTIAL FUMIO ITO, NORIAKI FUJITSUKA, M A S A H I R O SOKABE and ATSUSHI YOSHIMURA* Department of Physiology, Nagoya University School of Medicine, Nagoya 466 During stretching of muscle spindles isolated from semitendinosus muscles of the frog, Rana catesbeiana, the spindle potential was recorded from a m y e l i n a t e d segment placed ing~n air-gap. Most of the spindle p o t e n t i a l s were abolished on treatment with Ca ~ -channel without any decrease in the ampli+ .blockers, . . . causing . . tude of the afferent Na -splke. Durlng appllcatlon of the d e p o l a r l z l n g currents between 0.2 and 5 nA, the static component of the spindle potential was reversed and a slight decrease in the transgap impedance and in the amplitude of the Na-sp~kes were observed. In normal Ringer's solution, the amplitudes of afferent Na -spikes and the peak of spindle potential were linearly increased and decreased during application of hyper- a n ~ d e p o l a r i z i n g currents of up to 60 nA respectively, during which the rate of the Na -spikes was n o % modified. These results imply that the spindle potential is mainly due to the Ca ~ t inflow and is independent of the m e c h a n o e l e c t r i c t r a n s d u c t i o n in the muscle spindle. When a spindle receptor is stretched in an isotonic sucrose solution containing 1 mM L-arginine, a small depolarizing potential at the end of the dynamic stretch is followed by a larger hyperpolarization. The h y p ~ r p o l a r i z i n g spindle potential is abolished by K channel blockers. Since the K -channels along the sensory terminal become ~locked, the transgap impedance and the a m p l i t u d e s of the ~pindle potential and Na -spikes are increased. The peak and static rates of Na'-spikes depend on the strength of the imposed polarizing currents of up to 60 hA. These results suggest that in an axonal r e g i o ~ (around the first node) proximal to the encoding site for afferent impulse, K -channels act with both orth~dromic and antidromic d e p o l a r i z i n g currents in normal Ringer's solution. The K -channel activation may contribute to the slow a d a p t a t i o n of the spindle potential elicited by orthodromic depolarization (including a part of the receptor potential), and may also protect misfiring by decreasing the impedance to antidormic d e p o l a r i z i n g currents, as in large muscle action currents.
SENSORY INNERVATIONS OF THE GENITAL ORGANS IN THE FEMALE YOUNG DOGS USING RETROGRADE AND ANTEROGRADE A X O N A L TRANSPORT OF WGA-HRP. MASATOSHI M O R I M O T O ~ ) Y O S H I O T A N I G U T I ~ ) * T A D A H I D E TOTOKI~ )*and TAKESHI KANASEKI~ ) i) Department of Anatomy, Faculty of Medicine, Kyushu University, 3-1-1, Maidashi, Fukuoka, 812, and 2) Department of Anesthesiology, Saga Medical School, Nabeshima, Saga, 840-01, Japan Sensory innervations of the female genital organs (ovary, oviduct, uterine horn, uterine cervix, and vagina) of young dogs were examined using anterograde and retrograde axonal transport of WGA-HRP. For the operation and fixation, the experimental animals were deeply anesthetized. After injections into the left ovary and oviduct, most labeled cells were found in the ipsilateral TI3, L1 and LI,2 dorsal root ganglia (DRGs) respectively. Following injections into the left uterine horn, most labeled cells were observed in the ipsilateral L2,3 and SI-3 DRGs. Injections into these organs resulted in bilateral labeling with most labeled cells occurring in the ipsilateral DRGs. A small number of labeled cells were found in L2 and L3 DRGs after injections into the uterine cervix. Following injections into the wall of the vagina, many labeled cells were observed in L2,3 and SI-3 DRGs. After injections of WGA-HRP into the a b o v e - m e n t i o n e d ganglia, the following conclusions were obtained: In the ovary, many labeled fiber bundles were observed in the medulla, while in the cortex, labeled fibers formed fiber networks and were also seen just beneath the germinal epithelium. In the ampulla and isthmus of the oviduct, many labeled fibers were found in the smooth muscle coats and some labeled fibers were observed in the mucosal folds. In the uterine horn, a large number of labeled fiber bundles were observed in the m e s o m e t r i u m and some of them entered the endometrium through the myometrium. In the uterine cervix, some labeled fiber bundles were observed in the serous membranes and a small number of labeled fibers were seen in the lamina propria and epithelium. In the vagina, many labeled fibers were found in the fibrous adventitia after injections into SI-3 DRGs, and some fibers were seen in the stratified squamous epithelium. Some labeled fibers were seen to be terminated in the e p i t h e l i u m of the oviduct, uterine horn and cervix, and vagina.