Central and peripheral organization of the kinesthetic system studied by natural stimulation of peripheral receptors

1984 ◽  
Vol 98 (5) ◽  
pp. 1607-1608
Author(s):  
V. A. Fedan ◽  
E. Yu. Golov ◽  
V. A. Shepelev
Keyword(s):  
Natural Stimulation ◽  
Kinesthetic System ◽  
Stimulation Of

The Activity of Lateral-Line Efferent Neurones in Stationary and Swimming Dogfish

1972 ◽  
Vol 57 (2) ◽  
pp. 435-448 ◽  
Author(s):  
B. L. ROBERTS ◽  
I. J. RUSSELL
Keyword(s):  
Lateral Line ◽  
Body Movement ◽  
Cranial Nerves ◽  
Regulatory System ◽  
The Body ◽  
Muscle Fibres ◽  
Sense Organs ◽  
Efferent System ◽  
Natural Stimulation ◽  
Stimulation Of

1. The activity of efferent neurones innervating lateral-line organs on the body of dogfish was followed by recording from filaments of cranial nerve X in 41 decerebrate preparations. 2. The efferent nerves were not spontaneously active. 3. Tactile stimulation to the head and body, vestibular stimulation and noxious chemical stimulation were followed by activity of the efferent nerves. 4. In contrast, natural stimulation of lateral-line organs (water jets) did not reflexly evoke discharges from the efferent fibres. 5. Reflex efferent responses were still obtained to mechanical stimulation even after the lateral-line organs had been denervated. 6. Electrical stimulation of cranial nerves innervating lateral-lines organs was followed by reflex activity of the efferent fibres. But similar stimuli applied to other cranial nerves were equally effective in exciting the efferent system. 7. Vigorous movements of the fish, involving the white musculature, were preceded and accompanied by activity of the efferent fibres which persisted as long as the white muscle fibres were contracting. 8. Rhythmical swimming movements were accompanied by a few impulses in the efferent fibres grouped in bursts at the same frequency as the swimming movements. 9. It is concluded that the efferent neurones cannot contribute to a feedback regulatory system because they are not excited by natural stimulation of the lateral-line sense organs. The close correlation found between efferent activity and body movement suggests that the efferent system might operate in a protective manner to prevent the sense organs from being over-stimulated when the fish makes vigorous movements.

Activity of commissural interneurons in spinal cord of Xenopus embryos

1984 ◽  
Vol 51 (6) ◽  
pp. 1257-1267 ◽  
Author(s):  
S. R. Soffe ◽  
J. D. Clarke ◽  
A. Roberts
Keyword(s):  
Spinal Cord ◽  
Rhythmic Activity ◽  
Excitatory Input ◽  
Cycle Period ◽  
Fictive Locomotion ◽  
Anatomy And Physiology ◽  
Postsynaptic Potential ◽  
Natural Stimulation ◽  
Xenopus Laevis Embryos ◽  
Stimulation Of

Horseradish peroxidase- (HRP) filled microelectrodes have been used to examine the anatomy and physiology of "commissural interneurons," a morphologically defined class of spinal cord interneuron in Xenopus laevis embryos. Commissural interneurons have unipolar cell bodies in the dorsal half of the spinal cord. Their dendrites lie in the mid to ventral parts of the lateral tracts and their axons cross the cord ventrally, T branch, and ascend and descend on the opposite side of the cord. Recordings were made from animals immobilized in tubocurarine and responding to natural stimulation with three patterns of fictive motor activity. During episodes of fictive swimming, commissural interneurons are phasically excited to fire 1 spike/cycle in phase with motor discharge on the same side and receive a midcycle inhibitory postsynaptic potential (IPSP) in phase with motor discharge on the opposite side. Rhythmic activity is superimposed on a background depolarization. During periods of synchrony, phasic excitatory input doubles in frequency so that cells fire with half the swimming cycle period. The background depolarization is generally stronger than during swimming. During periods of fictive struggling, evoked by electrical stimulation of the skin, commissural interneurons fire a burst of spikes per cycle, cells being relatively hyperpolarized when motoneurons on the opposite side are active. In response to ipsilateral skin stimulation, some cells receive an IPSP at a latency of 12-20 ms. This precedes the onset of fictive locomotion. We discuss how anatomy and activity of commissural interneurons is suitable for a reciprocal inhibitory role.

Entrainment of respiration to rocking in premature infants: coherence analysis

1994 ◽  
Vol 77 (3) ◽  
pp. 1548-1554 ◽  
Author(s):  
M. P. Sammon ◽  
R. A. Darnall
Keyword(s):  
Premature Infants ◽  
Neonatal Intensive Care ◽  
Breathing Pattern ◽  
Respiratory Pattern ◽  
Coherence Analysis ◽  
Maturational Change ◽  
Natural Stimulation ◽  
Postconceptional Age ◽  
Intensive Care Nursery ◽  
Stimulation Of

Vestibular influences on breathing pattern were investigated in 18 premature infants in the neonatal intensive care nursery. Respiratory abdominal movements were recorded while the babies were manually rocked at varying rates between 30 and 60 cycles/min (cpm). Coherence spectra were estimated between the respiratory and rocker signals, and their magnitudes were evaluated at the rocking frequency, with coherence spectra > 0.85 indicative of strong entrainment to rocking. At least one incident of entrainment was seen in 15 of 18 infants, with 2:1 ratios (2 breaths/rocker cycle) occurring at rocking frequencies of 30–40 cpm (8 of 18 subjects) and 1:1 entrainment at rates of 42–50 cpm (5 of 18 subjects). More complex synchronization was observed in three infants, with patterns consisting of alternans between 2:1 and 3:2 ratios (5:3 entrainment). Infants > 35 wk postconceptional age exhibited greater coherence to rocking than infants < 35 wk (P < 0.01), indicating a maturational change in the reflex may occur. Results show that the natural stimulation of rocking a newborn provides a phasic input to its respiratory pattern generator that is capable of resetting the system's oscillation and entraining its rhythm.

Sympathetic nerve activity during natural stimulation of horizontal semicircular canals in humans

1998 ◽  
Vol 275 (4) ◽  
pp. R1274-R1278 ◽  
Author(s):  
Chester A. Ray ◽  
Keith M. Hume ◽  
Samuel L. Steele
Keyword(s):  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Semicircular Canals ◽  
Head Rotation ◽  
Otolith Organs ◽  
Nerve Activity ◽  
Natural Stimulation ◽  
Vascular Beds ◽  
Static Head ◽  
Stimulation Of

We have shown that static head-down neck flexion elicits increases in muscle (MSNA) but not skin sympathetic nerve activity (SSNA) in humans. These findings suggest that stimulation of the otolith organs causes differential sympathetic outflow to vascular beds. The purpose of the present study was to determine whether yaw head rotation (YHR), which stimulates the horizontal semicircular canals, elicits sympathetic nerve responses. To test this question, we recorded MSNA ( n = 33) and SSNA ( n = 25) before and during 3 min of sinusoidal YHR performed at 0.1, 0.6, and 1.0 Hz. At all frequencies, YHR elicited no significant changes in heart rate and mean arterial pressure. Likewise, YHR did not significantly change either MSNA or SSNA at all frequencies. Our results indicate that stimulation of the horizontal semicircular canals by YHR does not alter SNA to either muscle or skin. Moreover, these results provide evidence to support the concept that the otolith organs but not the horizontal semicircular canals participate in the regulation of SNA in humans.

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