Intracellular Recording From Motoneurons of the Cervical Spinal Cord of the Cat

Rf, Schmidt; Wd, Willis

doi:10.1152/jn.1963.26.1.28

Cited by 27 publications

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This finding has been extended to include motoneurones in other regions of the spinal cord (Schmidt & Willis, 1963;Sears, 1964). The motoneurones of muscles which extend the head also receive monosynaptic e.p.s.p.s from homonymous and heteronymous muscle afferents (Wilson & Maeda, 1974;Anderson, 1977).…”

Section: Introductionmentioning

confidence: 78%

“…Electrophysiological studies in th lumbo-sacral segments of the spinal cord have revealed that az-motoneurones receive excitatory monosynaptic connexions from Ia afferents of their own and synergistic muscles (Lloyd, 1946;Mendell & Henneman, 1971). This finding has been extended to include motoneurones in other regions of the spinal cord (Schmidt & Willis, 1963;Sears, 1964). The motoneurones of muscles which extend the head also receive monosynaptic e.p.s.p.s from homonymous and heteronymous muscle afferents (Wilson & Maeda, 1974;Anderson, 1977).…”

Section: Introductionmentioning

confidence: 78%

See 1 more Smart Citation

Reflex connexions of motoneurones of muscles involved in head movement in the cat.

Rapoport¹

1979

The Journal of Physiology

View full text Add to dashboard Cite

SUMMARY1. The reflex connexions from muscle afferents and ventral root fibres to the motoneurones of the muscles biventer-cervicis, complexus, sternocleidomastoid, trapezius and splenius, the principal muscles involved in head movement in the cat, were studied with the technique of intracellular recording.2. Electrical stimulation of homonymous muscle afferents of biventer-cervicis and complexus, sternocleidomastoid and trapezium, at strengths below 1P6 times threshold of the dorsal root afferent volley, produced monosynaptic e.p.s.p.s in the corresponding motoneurones. Recruitment of higher threshold muscle afferents

show abstract

Section: Introductionmentioning

confidence: 78%

Section: Introductionmentioning

confidence: 78%

Reflex connexions of motoneurones of muscles involved in head movement in the cat.

Rapoport¹

1979

The Journal of Physiology

View full text Add to dashboard Cite

show abstract

“…The maximal I a EPSPs evoked in TLo motoneurones from the different Tri nerves were positively correlated with each other (Table 4). With exception of FCR no I a excitation was present in the elbow extensor motoneurones from distal forelimb muscles (Table 7; Schmidt & Willis, 1963). All Tri muscles projected unidirectional Ia pathways to the ECU, Sup and APL motor nuclei.…”

Section: Patterns Of Ia Connectionsmentioning

confidence: 92%

“…Despite several studies on the Ia connections of the cat and monkey forelimb (Clough, Kernell & Phillips, 1968;Eccles et al 1957;Eccles & Lundberg, 1958;Schmidt & Willis 1963; Willis, Tate, Ashworth & Willis, 1966) our knowledge on their organization has remained superficial. This is a drawback since the upper extremity receives increasing interest in current research on motor control.…”

Section: Introductionmentioning

confidence: 99%

Pattern of monosynaptic Ia connections in the cat forelimb.

Fritz¹,

Illert²,

Motte³

et al. 1989

The Journal of Physiology

159

View full text Add to dashboard Cite

SUMMARY1. In anaesthetized cats intracellular records were obtained from antidromically identified motoneurones. The motor nuclei to the elbow extensor and flexor muscles and to the muscles innervated by the deep radial, ulnar and median nerves were investigated. The maximum Ia EPSPs from electrical stimulation of various peripheral nerves were measured. The characteristic convergence and projection patterns to each motor nucleus were established from pooled data.2. The total aggregates of the I a EPSPs between the different motor nuclei ranged from 3-5 to 11-7 mV. The smallest aggregates were found in the nuclei to the digit muscles. The ratio of the heteronymous versus homonymous EPSP amplitudes varied between 3-9 and 05. A general rule which would govern the distribution of the EPSP aggregates, such as a proximo-distal. gradient, was not observed.3. The Ia connections followed a complex but highly organized pattern. Bidirectional and unidirectional pathways were present. In many cases the convergence pattern of a motor nucleus included muscles acting at different joints. The connections of one nucleus were not necessarily restricted to one side of the limb, but could cross the radio-ulnar plane.4. Muscles with similar actions onto the same joint were interconnected with bidirectional, rather balanced I a pathways. Such relations were also present between close functional synergists and then often extended across several joints. The relations between the anatomical extensors of wrist and digits were graded according to the neighbourhood of these muscles. It is suggested that this reflects the graded mechanical synergism in the wrist action of these muscles.5. A large number of unidirectional or strongly skewed bidirectional Ia pathways project from proximal to distal muscles. It is suggested that they may serve a readjustment of distal joints during changes in the position of proximal ones (e.g. stabilization of the position of the radio-ulnar plane during elbow extension in case of the unidirectional projections onto supinator and abductor pollicis longus motoneurones).

show abstract

“…Previous electrophysiological studies of mature mammalian spinal cord motoneurons have been largely carried out on intact animals (Araki and Terzuolo, 1962;Blankenship and Kuno, 1968;Ito and Oshima, 1965;Pierau et al, 1976;Schlue et al, 1974;Schmidt and Willis, 1963). Although this approach has the advantages of preserving motoneurons and the associated spinal cord circuitry, it has some limitations, such as mechanical instability, susceptibility to the anesthetic agents employed, and challenges related to the controlled delivery of pharmacological agents (Kerkut and Bagust, 1995).…”

Section: Introductionmentioning

confidence: 99%