Position sensitivity of human muscle spindles

Single afferent and population representations

Paul Cordo, Carmen Flores-Vieira, Sabine M P Verschueren, J. Timothy Inglis, Victor Gurfinkel

Research output: Contribution to journalArticle

60 Citations (Scopus)

Abstract

The representation of joint position at rest and during movement was investigated in 44 muscle spindle primary afferents originating from the extensor carpi radialis brevis (ECRb) and extensor digitorum (ED) of normal human subjects. Position sensitivity was estimated for each afferent, and 43 of 44 were position sensitive. In each trial, six sequential ramp-and-hold movements (2-6°, 2°/s, total 24°) flexed the relaxed wrist, beginning from the angle at which the afferent was just recruited. Joint position was represented by three specific features of afferent firing patterns: the steady-state firing rate during the 4-s hold period between ramps, the initial burst at the beginning of each ramp, and the ramp increase in firing rate later in the movement. The position sensitivity of the initial burst (1.27 ± 0.90 pps/°, mean ± SD) was several times higher than that of the hold period (0.40 ± 0.30 pps/°) and not different from that of the ramp increase in firing rate (1.36 ± 0.68 pps/°). The wrist position sensitivities of ECRb and ED afferents were equivalent, as were their recruitment angles and angular ranges of position sensitivity. Muscle spindle afferents, both individually and as a population, were shown to represent static joint position via the hold rate and the initial burst. Afferents were recruited over the entire 110° range of wrist positions investigated; however, the angular range over which each feature represented joint position was extremely limited (≈15°). The population response, based on the summed activity of the 43 afferents, was monotonically related to joint position, and it was strongly influenced by the afferent recruitment pattern, but less so by the position sensitivities of the individual afferents.

Original languageEnglish (US)
Pages (from-to)1186-1195
Number of pages10
JournalJournal of Neurophysiology
Volume87
Issue number3
StatePublished - 2002

Fingerprint

Muscle Spindles
Architectural Accessibility
Joints
Wrist
Population

ASJC Scopus subject areas

  • Physiology
  • Neuroscience(all)

Cite this

Cordo, P., Flores-Vieira, C., Verschueren, S. M. P., Timothy Inglis, J., & Gurfinkel, V. (2002). Position sensitivity of human muscle spindles: Single afferent and population representations. Journal of Neurophysiology, 87(3), 1186-1195.

Position sensitivity of human muscle spindles : Single afferent and population representations. / Cordo, Paul; Flores-Vieira, Carmen; Verschueren, Sabine M P; Timothy Inglis, J.; Gurfinkel, Victor.

In: Journal of Neurophysiology, Vol. 87, No. 3, 2002, p. 1186-1195.

Research output: Contribution to journalArticle

Cordo, P, Flores-Vieira, C, Verschueren, SMP, Timothy Inglis, J & Gurfinkel, V 2002, 'Position sensitivity of human muscle spindles: Single afferent and population representations', Journal of Neurophysiology, vol. 87, no. 3, pp. 1186-1195.
Cordo P, Flores-Vieira C, Verschueren SMP, Timothy Inglis J, Gurfinkel V. Position sensitivity of human muscle spindles: Single afferent and population representations. Journal of Neurophysiology. 2002;87(3):1186-1195.
Cordo, Paul ; Flores-Vieira, Carmen ; Verschueren, Sabine M P ; Timothy Inglis, J. ; Gurfinkel, Victor. / Position sensitivity of human muscle spindles : Single afferent and population representations. In: Journal of Neurophysiology. 2002 ; Vol. 87, No. 3. pp. 1186-1195.
@article{d8c67caf9ecc4a35a071cfca685e6d20,
title = "Position sensitivity of human muscle spindles: Single afferent and population representations",
abstract = "The representation of joint position at rest and during movement was investigated in 44 muscle spindle primary afferents originating from the extensor carpi radialis brevis (ECRb) and extensor digitorum (ED) of normal human subjects. Position sensitivity was estimated for each afferent, and 43 of 44 were position sensitive. In each trial, six sequential ramp-and-hold movements (2-6°, 2°/s, total 24°) flexed the relaxed wrist, beginning from the angle at which the afferent was just recruited. Joint position was represented by three specific features of afferent firing patterns: the steady-state firing rate during the 4-s hold period between ramps, the initial burst at the beginning of each ramp, and the ramp increase in firing rate later in the movement. The position sensitivity of the initial burst (1.27 ± 0.90 pps/°, mean ± SD) was several times higher than that of the hold period (0.40 ± 0.30 pps/°) and not different from that of the ramp increase in firing rate (1.36 ± 0.68 pps/°). The wrist position sensitivities of ECRb and ED afferents were equivalent, as were their recruitment angles and angular ranges of position sensitivity. Muscle spindle afferents, both individually and as a population, were shown to represent static joint position via the hold rate and the initial burst. Afferents were recruited over the entire 110° range of wrist positions investigated; however, the angular range over which each feature represented joint position was extremely limited (≈15°). The population response, based on the summed activity of the 43 afferents, was monotonically related to joint position, and it was strongly influenced by the afferent recruitment pattern, but less so by the position sensitivities of the individual afferents.",
author = "Paul Cordo and Carmen Flores-Vieira and Verschueren, {Sabine M P} and {Timothy Inglis}, J. and Victor Gurfinkel",
year = "2002",
language = "English (US)",
volume = "87",
pages = "1186--1195",
journal = "Journal of Neurophysiology",
issn = "0022-3077",
publisher = "American Physiological Society",
number = "3",

}

TY - JOUR

T1 - Position sensitivity of human muscle spindles

T2 - Single afferent and population representations

AU - Cordo, Paul

AU - Flores-Vieira, Carmen

AU - Verschueren, Sabine M P

AU - Timothy Inglis, J.

AU - Gurfinkel, Victor

PY - 2002

Y1 - 2002

N2 - The representation of joint position at rest and during movement was investigated in 44 muscle spindle primary afferents originating from the extensor carpi radialis brevis (ECRb) and extensor digitorum (ED) of normal human subjects. Position sensitivity was estimated for each afferent, and 43 of 44 were position sensitive. In each trial, six sequential ramp-and-hold movements (2-6°, 2°/s, total 24°) flexed the relaxed wrist, beginning from the angle at which the afferent was just recruited. Joint position was represented by three specific features of afferent firing patterns: the steady-state firing rate during the 4-s hold period between ramps, the initial burst at the beginning of each ramp, and the ramp increase in firing rate later in the movement. The position sensitivity of the initial burst (1.27 ± 0.90 pps/°, mean ± SD) was several times higher than that of the hold period (0.40 ± 0.30 pps/°) and not different from that of the ramp increase in firing rate (1.36 ± 0.68 pps/°). The wrist position sensitivities of ECRb and ED afferents were equivalent, as were their recruitment angles and angular ranges of position sensitivity. Muscle spindle afferents, both individually and as a population, were shown to represent static joint position via the hold rate and the initial burst. Afferents were recruited over the entire 110° range of wrist positions investigated; however, the angular range over which each feature represented joint position was extremely limited (≈15°). The population response, based on the summed activity of the 43 afferents, was monotonically related to joint position, and it was strongly influenced by the afferent recruitment pattern, but less so by the position sensitivities of the individual afferents.

AB - The representation of joint position at rest and during movement was investigated in 44 muscle spindle primary afferents originating from the extensor carpi radialis brevis (ECRb) and extensor digitorum (ED) of normal human subjects. Position sensitivity was estimated for each afferent, and 43 of 44 were position sensitive. In each trial, six sequential ramp-and-hold movements (2-6°, 2°/s, total 24°) flexed the relaxed wrist, beginning from the angle at which the afferent was just recruited. Joint position was represented by three specific features of afferent firing patterns: the steady-state firing rate during the 4-s hold period between ramps, the initial burst at the beginning of each ramp, and the ramp increase in firing rate later in the movement. The position sensitivity of the initial burst (1.27 ± 0.90 pps/°, mean ± SD) was several times higher than that of the hold period (0.40 ± 0.30 pps/°) and not different from that of the ramp increase in firing rate (1.36 ± 0.68 pps/°). The wrist position sensitivities of ECRb and ED afferents were equivalent, as were their recruitment angles and angular ranges of position sensitivity. Muscle spindle afferents, both individually and as a population, were shown to represent static joint position via the hold rate and the initial burst. Afferents were recruited over the entire 110° range of wrist positions investigated; however, the angular range over which each feature represented joint position was extremely limited (≈15°). The population response, based on the summed activity of the 43 afferents, was monotonically related to joint position, and it was strongly influenced by the afferent recruitment pattern, but less so by the position sensitivities of the individual afferents.

UR - http://www.scopus.com/inward/record.url?scp=0036097887&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0036097887&partnerID=8YFLogxK

M3 - Article

VL - 87

SP - 1186

EP - 1195

JO - Journal of Neurophysiology

JF - Journal of Neurophysiology

SN - 0022-3077

IS - 3

ER -