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1.
Fluctuations in dorsal root potential (DRP) were investigated in trials on white rats during two types of locomotion, differing in the intensity of afferent flow (swimming and walking). Two negative waves of DRP were observed corresponding to the stance (or propulsive) phase and the swing (or transfer) phase within a single locomotor cycle. Whereas DRP had risen primarily during the stroke phase with increased intensity during swimming, it increased during the standing phase in walking. A relationship was revealed between the amplitude of DRP and the intensity of afferent flow apparent during passive displacement of the limb, as well as locomotion. It is concluded that DRP waves are mainly due to influences from peripheral afferents during actual locomotion.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 20, No. 3, pp. 333–340, May–June, 1988. 相似文献
2.
Microinjections of aspartic acid and chlorpromazine into the region of the locus coeruleus, which strengthen spontaneous unit activity in that structure, in decerebellate cats anesthetized with chloralose, led to depression of the inhibitory influence of flexor reflex afferents on extensor discharges, but did not change the facilitatory action of these afferents on flexor monosynaptic discharges and had no effect on recurrent inhibition of extensor discharges or reduced it. Microinjection of noradrenalin into this region, which depresses spontaneous unit activity in the locus coeruleus, or of procaine, which blocks action potential generation in neurons, led to potentiation of the inhibitory action of flexor reflex afferents on extensor discharges and to strengthening of recurrent inhibition, but did not affect the facilitatory action of these afferents on flexor discharges. The role of tonic descending influences of the locus coeruleus in the control of spinal inhibition evoked by flexor reflex afferents is discussed.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 13, No. 3, pp. 247–256, May–June, 1981. 相似文献
3.
A. I. Pilyavskii N. V. Bulgakova R. Maldonado B. P. Roques V. A. Yakhnitsa 《Neurophysiology》1999,31(5):316-322
Effects of a selective agonist of delta-opioid receptors, BUBU, and mixed inhibitors of enkephalin-degrading enzymes, RB-38A
and RB-101, on the background and evoked activity of periaqueductal gray (PAG) neurons were studied on slices of the rat midbrain.
The tested drugs could either activate or depress spontaneously active neurons, or exert no influence on these units, “Silent”
neurons generated no responses to application of the above compounds. In 80.5% of the studied neurons, 1 μM BUBU evoked depression,
while 6.5 μM RB-38A, 0.65 mM RB-38A, and 10 μM RB-101 depressed 68.8%, 73.7% and 68.8% of the neurons, respectively. Facilitatory
effects were induced by the above drugs in 5.0%, 5.9%, 15.8%, and 6.2% of the cells under study, respectively. The effects
of RB-38A and RB-101 differed from the BUBU-evoked responses in a shorter latency and rise time and a higher intensity. Repeated
application of RB-38A provided no significant changes in the duration and intensity of the inhibitory effects. Co-administration
of RB-38A and BUBU, or BUBU and RB-38A intensified suppression of the neuronal discharges without considerable changing their
duration. It is concluded that administration of inhibitors of enkephalin-degrading enzymes toin vitro midbrain preparations creates a pharmacologically effective level of endogenous enkephalins, which exerts specific inhibitory
influence on spontaneously active PAG neurons. The data are in agreement with the supposition on the existence of tonic release
of enkephalins in midbrain slice preparations. 相似文献
4.
A study was done on base activity and changes in base activity (BA) of neurons in periaqueductal gray matter (PAG) during stimulation of monoaminergic structures of the brainstem: the nucleus raphe magnus (NRM), the locus coeruleus (LC), and the substantia nigra (SN), in rats anesthetized with hexenal (200 mg/kg). Three types of PAG neurons that differed in BA structure were identified. NRM, LC and SN stimulation changed BA only in type III neurons. Stimulation of these structures evoked an increase in BA frequency in 11.0–14.5%, and inhibition in 31.0–47.5% of type III neurons. Simultaneous stimulation of two structures led to a marked drop in intensity of effects. A depressing effect on BA was always detected if stimulation of one of the structures suppressed BA. Stimulation of two structures, with one being the NRM, was most effective. The role of PAG in the organization of the brain-stem component of the antinociceptive mechanism is discussed.A. A. Bogomolets Institute of Physiology, Ukrainian Academy of Sciences, Kiev. Translated from Neirofiziologiya, Vol. 24, No. 1, pp. 52–60, January–February, 1992. 相似文献
5.
Postsynaptic potentials of 93 motoneurons of the masseter muscle evoked by stimulation of different branches of the trigeminal nerve were studied. Stimulation of the most excitable afferent fibers of the motor nerve of the masseter muscle evoked monosynaptic EPSPs with a latent period of 1.2–2.0 msec, changing into action potentials when the strength of stimulation was increased. A further increase in the strength of stimulation produced an antidromic action potential in the motoneurons with a latent period of 0.9 msec. In some motoneurons polysynaptic EPSPs and action potentials developed following stimulation of the motor nerve to the masseter muscle. The ascending phase of synaptic and antidromic action potentials was subdivided into IS and SD components, while the descending phase ended with definite depolarization and hyperpolarization after-potentials. Stimulation of cutaneous branches of the trigeminal nerve, and also of the motor nerve of the antagonist muscle (digastric) evoked IPSPs with a latent period of 2.7–3.5 msec in motoneurons of the masseter muscle. These results indicate the existence of functional connections between motoneurons of the masseter muscle and its proprioceptive afferent fibers, and also with proprioceptive afferent fibers of the antagonist muscle and cutaneous afferent fibers.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 1, No. 3, pp. 262–268, November–December, 1969. 相似文献
6.
High- and low-threshold reflex segmental reflex reactions produced by stimulating the dorsal root at different stages of the locomotor cycle were investigated during locomotor swimming motions in white rats. Findings show respectively considerable inhibition of and a pronounced increase in extensor and flexor lowthreshold reflex reactions during the absence and presence of activity in the associated muscles. Low-threshold stimulation produced no outstanding effect on the shaping of the muscles' own activity and hence failed to affect time course or amplitude parameters of locomotor movements. Changes in reflex reactions to high-threshold stimulation during the locomotor cycle largely resembled changes in these responses to low-threshold stimulation, although development of highthreshold reactions differed from that of low-threshold response in affecting the parameters of locomotor activity in the associated muscle, while likewise altering frequency parameters of the locomotor rhythm. The physiological significance and mechanisms possibly underlying modulations in the efficacy of afferent peripheral influences during locomotion are discussed.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 20, No. 3, pp. 326–333, May–June, 1988. 相似文献
7.
8.
O. V. Vlasenko A. V. Dovgan’ A. I. Pilyavskii V. A. Maisky A. V. Maznichenko 《Neurophysiology》2009,41(2):148-156
The expression of early c-fos gene (marker of neuronal activation) and NADPH-diaphorase reactivity (NADPH-dr) was studied in various hypothalamic structures
of rats in the norm, in the state of starvation, and after realization of long-lasting (repeated 4 to 12 times per minute
for 30 min) motivated stereotyped food-procuring forelimb movements. In rats in the starving state, as compared with the control,
the densities (number of units within a 200 × 200 μm2 test area of a 40-μm-thick slice) of Fos-immunoreactive (Fos-ir) neurons in the parvicellular part of the paraventricular
nucleus (Ра), supraoptic (SO), and medial preoptic (МРО) nuclei, anterior hypothalamic region (АН), and lateral hypothalamic nucleus (LH) were significantly greater (Р < 0.05) than in the control. In the dorsomedial (DMD) and ventromedial (VMHD) hypothalamic nuclei, this index did not differ from control values. After the performance of intense unilateral operant
movements, higher densities of labeled neurons (as compared with that in control and starving animals) were observed in the
PаAP, SO, МРО, and DMD, while smaller densities were observed in the LH and VMH. NADPH-dr neurons (i.e., NO synthase-containing cells) were observed in many hypothalamic nuclei; the maximum density of
such NO-generating neurons was found in the Pa, SO, MPO, and DMD. The overwhelming majority of Fos-ir and NADPH-dr neurons in neurons was observed after realization of stereotyped food-procuring
movements in the Ра and SO. This specificity of changes in the number of Fos-irand NADPH-dr neurons in the hypothalamic nuclei reflects, perhaps, the
involvement of these structures in the control of autonomic functions in the course of realization of operant reflexes and
adaptation of the function of the cardiovascular system to the corresponding intense physical and emotional loading. 相似文献
9.
Experiments on cats anesthetized with chloralose showed that repetitive stimulation of the locus coeruleus is accompanied by a decrease in IPSPs evoked by stimulation of flexor reflex afferents in extensor motoneurons. The effect appeared 600 msec after the beginning of stimulation and reached its maximum after 1500–2000 msec. Repetitive stimulation of the locus coeruleus did not change the membrane potential and did not affect EPSPs or IPSPs evoked by stimulation of low-threshold muscle afferents; EPSPs due to activation of high-threshold cutaneous and muscle afferents likewise remained unchanged. Repetitive stimulation of more central regions of the brain stem was accompanied not only by a decrease in IPSPs evoked by stimulation of flexor reflex afferents in extensor motoneurons, but also by a decrease in amplitude of EPSPs arising in response to stimulation of these same afferents in flexor motoneurons. These effects were not connected with activation of monoaminergic structures, for unlike effects arising during stimulation of the locus coeruleus, they were also found in previously reserpinized animals.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 14, No. 1, pp. 51–59, January–February, 1982. 相似文献
10.
A. I. Pilyavskii A. V. Maznychenko V. A. Maiskii V. V. Korneyev A. I. Kostyukov 《Neurophysiology》2011,43(3):240-243
Vibrational stimulation of the tendon of the mm.gastrocnemius+soleus (100 sec–1) in rats anesthetized with chloral hydrate (400 mg/kg) resulted in the appearance of considerable Fos immunoreactivity in
the lumbar spinal cord (L1-L6), as compared with that in intact animals. Total densities of Fos-immunopositive (Fos-ip) neurons in each of the examined
segments were higher than 40 units per 40-μm-thick slice; the respective index reached the maximum at the L4 level (78.9 ± 2.3 cells). Most Fos-ip neurons were localized in laminae 4 to 7 of the gray matter, both ipsi- and contralaterally
with respect to the side of stimulation (28.5 ± 0.6 and 28.4 ± 0.6, respectively). Single Fos-ip motoneurons were found bilaterally
in the ventral horn motor nuclei. Thus, activation of muscle spindle receptors induced by vibrational stimulation applied
to the Achilles tendon induces noticeable bilateral c-fos expression in spinal neuronal networks related to transmission of proprioceptive muscle-born impulsation. 相似文献