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1.
Marsala J Lukácová N Kolesár D Kuchárová K Marsala M 《Cellular and molecular neurobiology》2006,26(7-8):1385-1410
1. The aim of the present study was to examine the occurrence of the neuronal nitric oxide synthase immunoreactivity in the stretch reflex circuit pertaining to the quadriceps femoris muscle in the dog.2. Immunohistochemical processing for neuronal nitric oxide synthase and histochemical staining for nicotinamide adenine dinucleotide phosphate diaphorase were used to demonstrate the presence of neuronal nitric oxide synthase in the proprioceptive afferents issuing in the quadriceps femoris muscle. The retrograde tracer Fluorogold injected into the quadriceps femoris muscle was used to detect the proprioceptive afferents and their entry into the L5 and L6 dorsal root ganglia.3. A noticeable number of medium-sized intensely nitric oxide synthase immunolabelled somata (1000–2000 μm2 square area) was found in control animals in the dorsolateral part of L5 and L6 dorsal root ganglia along with large-caliber intraganglionic nitric oxide synthase immunolabelled fibers, presumed to be Ia axons. Before entering the dorsal funiculus the large-caliber nitric oxide synthase immunolabelled fibers of the L5 and L6 dorsal roots formed a massive medial bundle, which upon entering the dorsal root entry zone reached the dorsolateral part of the dorsal funiculus and were distributed here in a funnel-shaped fashion. The largest nitric oxide synthase immunolabelled fibers, 8.0–9.2 μm in diameter, remained close to the dorsal horn, while medium-sized fibers were seen dispersed across the medial portion of the dorsal funiculus. Single, considerably tapered nitric oxide synthase immunolabelled fibers, 2.2–4.6 μm in diameter, were seen to proceed in ventrolateral direction until they reached the mediobasal portion of the dorsal horn and the medial part of lamina VII. In lamina IX, only short fragments of nitric oxide synthase immunoreactive fibers and their terminal ramifications could be seen. Nitric oxide synthase immunolabelled terminals varying greatly in size were identified in control material at the base of the dorsal horn, in the vicinity of motoneurons ventrally and ventrolaterally in L5 and L6 segments and in Clarke’s column of L3 and L4 segments. Injections of the retrograde tracer Fluorogold into the quadriceps femoris muscle and cut femoral nerve, combined with nitric oxide synthase immunohistochemistry of the L5 and L6 dorsal root ganglia, confirmed the existence of a number of medium-sized nitric oxide synthase immunoreactive and Fluorogold-fluorescent somata presumed to be proprioceptive Ia neurons (1000–2000 μm2 square area) in the dorsolateral part of both dorsal root ganglia. L5 and L6 dorsal rhizotomy caused a marked depletion of nitric oxide synthase immunoreactivity in the medial bundle of the L5 and L6 dorsal roots and in the dorsal funiculus of L5 and L6 segments.4. The analysis of control material and the degeneration of the large- and medium-caliber nitric oxide synthase immunoreactive Ia fibers in the dorsal funiculus of L5 and L6 segments confirmed the presence of nitric oxide synthase in the afferent limb of the monosynaptic Ia-motoneuron stretch reflex circuit related to the quadriceps femoris muscle.
Abbreviations ABC, avidin–biotin complex; bNOS, neuronal nitric oxide synthase; bNOS-IR, neuronal nitric oxide synthase immunoreactive; bNOS-IRBs, neuronal nitric oxide synthase immunoreactive boutons; cNOS, catalytic nitric oxide synthase; DAB, diaminobenzidine; DF, dorsal funiculus; DH, dorsal horn; DREZ-one, dorsal root entry zone; DRGs, dorsal root ganglia; eNOS, endothelial nitric oxide synthase; FG, Fluorogold; FN, femoral nerve; mNOS, macrophage nitric oxide synthase; NADPHd, nicotinamide adenine dinucleotide phosphate diaphorase; NBT, nitroblue tetrazolium; NO, nitric oxide; NOS, nitric oxide synthase; NOS-IR, nitric oxide synthase immunoreactive; PBS, phosphate-buffered saline; VGLUT1 and VGLUT2, vesicular glutamate transporters 相似文献
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Kevin T. Beier Xiaojing J. Gao Stanley Xie Katherine E. DeLoach Robert C. Malenka Liqun Luo 《Cell reports》2019,26(1):159-167.e6
4.
We studied the relations between conditions of induction and quantitative characteristics of abnormally amplified monosynaptic
reflex discharges (MSD) in ventral roots (VR) observed in two experimental situations: (i) 5 days after simultaneously performed
denervation (transection of the sciatic nerve) and spinalization at the L
1 level, and (ii) 5 days after preliminary denervation and with systemic injection of 4-aminopyridine (4-AP) in the course
of the acute experiment. In both situations, the amplitude of the MSD conducted via the VR was close to the threshold of excitation
of fibers in this root or even exceeded this value (a superreflexia phenomenon). Under both (i) and (ii) conditions, we observed
generation of the second component of MSD in the VR, which was probably related to transition of excitation from excited to
“silent” fibers in the VR. The latter of the above variants of induction superreflexia (5 days after denervation and with
the effect of 4-AP in the acute experiment) is preferred because there is practically no death of the experimental animals
in the course of the chronic experiment, there are no negative post-spinalization changes in the spinal cord, and the possibility
of supraspinal activation of motoneurons is preserved.
Neirofiziologiya/Neurophysiology, Vol. 37, No. 2, pp. 157–163, March–April, 2005. 相似文献
5.
The spinal superreflexia state was modeled in experiments on rats using preliminary transection of the spinal cord and injection
(in the course of the acute experiment) of 4-aminopyridine. An extremely high (reaching 15–20 mV) amplitude of monosynaptic
reflex discharges (MRs) evoked by stimulation of the dorsal root and recorded from the ventral root (VR) L
4 and the presence of an additional component in the above discharges were phenomena indicative of the development of the above
state. Under such conditions, the amplitudes of the discharges evoked in the VR by electrical stimulation of the round window
of the labyrinth (vestibular stimulation) and of the discharges elicited by stimulation of the motor cortex under conditions
of bilateral transection of the pyramids increased several times. Thresholds of the VR responses to vestibular and cortical
stimulations demonstrated an about threefold drop; latencies of the mass responses and responses of single spinal moto-and
interneurons decreased about twofold, on average. The pattern of vestibular conditioning effects on the VR MRs changed: in
intact animals vestibular stimulation induced inhibition of the VR MRs, while in animals with superreflexia such stimulation
led to facilitation of the MRs. Cortical stimulation under conditions of pyramidotomy in both intact animals and animals with
superreflexia resulted in facilitation of the VR MRs of a nearly the same intensity. The levels of convergence of the segmental
and supraspinal effects on interneurons and motoneurons of the rat spinal cord dramatically increased under superreflexia
conditions. The possible mechanisms of augmentation of the descending influences on spinal neuronal systems under the above
conditions are discussed.
Neirofiziologiya/Neurophysiology, Vol. 38, No. 2, pp. 140–149, March–April, 2006. 相似文献
6.
Haruki Nakano Takuji Miyasaka Toshihiko Ogino Akira Naito 《Somatosensory & motor research》2014,31(4):214-220
Group I muscle afferents modulate the excitability of motor neurons through excitatory and inhibitory spinal reflexes. Spinal reflex relationships between various muscle pairs are well described in experimental animals but not in the human upper limb, which exhibits a fine control of movement. In the present study, spinal reflexes between the extensor carpi radialis (ECR) and pronator teres (PT) muscles were examined in healthy human subjects using a post-stimulus time histogram method. Electrical stimulation of low-threshold afferents of ECR nerves increased the motor neuron excitability in 31 of 76 PT motor units (MUs) in all eight subjects tested, while stimulation of low-threshold afferents of PT nerves increased the motor neuron excitability in 36 of 102 ECR MUs in all 10 subjects. The estimated central synaptic delay was almost equivalent to that of homonymous facilitation. Mechanical stimulation (MS) of ECR facilitated 16 of 30 PT MUs in all five subjects tested, while MS of PT facilitated 17 of 30 ECR MUs in all six subjects. These results suggest excitatory reflex (facilitation) between PT and ECR. Group I afferents should mediate the facilitation through a monosynaptic path. 相似文献
7.
We studied monosynaptic reflex discharges (MRD) recorded from the ventral roots (VR) of rats subjected to systemic administration
with thyroliberin, thyroxin, or 4-aminopyridine (4-AP). Under such conditions, in some of the experiments the MRD amplitude
reached values sufficient to excite non-active VR fibers. In these cases, immediately after the MRD peak had been reached,
abnormally increased responses (AIR) developed, whose amplitude was 2–2.5 times higher than the amplitude of highly facilitated
MRD. Proofs are presented that AIR reflect excitation of “neighboring” VR fibers, which were not involved in the reflex response,
and MRD plays the role of a “stimulus” exciting these fibers. Therefore, we demonstrate the possibility of transmission of
excitation from “active” to “silent” fibers within a nerve trunk under conditions of the development of “superreflexia”. This
state can be considered a model of excitation spreading via a non-synaptic pathway under conditions of hyperexcitability of
the CNS structures, in seizure states in particular.
neirofiziologiya/Neurophysiology, Vol. 32, No. 2, pp. 120–127, March–April, 2000. 相似文献
8.
Wenjiao Tai Wei Wu Lei-Lei Wang Haoqi Ni Chunhai Chen Jianjing Yang Tong Zang Yuhua Zou Xiao-Ming Xu Chun-Li Zhang 《Cell Stem Cell》2021,28(5):923-937.e4
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9.
H. Steffens E. D. Schomburg A. V. Maznychenko V. A. Maisky A. I. Kostyukov A. I. Pilyavskii 《Neurophysiology》2007,39(3):191-200
Effects of long-term (9 days) experimental unilateral inflammation in the mm. gastrocnemius-soleus (GS), induced by injection of Freund’s complete adjuvant, namely modulation of posterior biceps-semitendinosus (PBSt) monosynaptic reflexes (MSRs), which was induced by chemical activation of high-threshold (groups III and I) muscle
afferents, and changes in c-fos expression and NADPH-diaphorase (d) reactivity in the lumbosacral spinal cord, were studied in anemically decapitated and
highly (at the C1) spinalized cats. The mean amplitude of the MSRs on the pretreated side did not differ significantly from that on the opposite
side. In adjuvant-injected cats, ipsilateral stimulation of nociceptive muscle afferents by KCl injection induced the bilateral
enhancement of flexor reflexes. Significant bilateral increases in the mean number of Fos-immunoreactive (Fos-IR) neurons
within the L6, L7, and S1 segments (157.5 ± 12.7, 201 ± 18.5, and 205 ± ± 18.6 per section; P < 0.05) were also found in adjuvant-injected cats. A lot of Fos-IR neurons was observed in the marginal zone (lamina I) and
the neck of the dorsal horn (laminae V and VI); the highest number of labelled cells was detected in lamina VII. In adjuvant-injected
cats, co-distribution of Fos-IR neurons and numerous Fos-IR glia-like cells in the dorsal and ventral horns was also found.
Significant increases in the mean number of NADPH-d-reactive cells in lamina VII bilaterally and also in lamina I and in an
area around the central canal (lamina X) contralaterally within the L6, L7, and S1 segments (P < 0.05) were also observed. In conclusion, activation of the nociceptive input during long-term inflammation of the GS muscles
is associated with differential patterns of c-fos expression and NADPH-d reactivity and also with central neuronal hyperexcitability that contributes to bilateral facilitation
of the PBSt MSRs.
Neirofiziologiya/Neurophysiology, Vol. 39, No. 3, pp. 222–231, May–June, 2007. 相似文献
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