A stretch reflex in extraocular muscles of species purportedly lacking muscle spindles

Abstract

It is generally assumed that proprioceptive feedback plays a crucial role in limb posture and movement. However, the role of afferent signals from extraocular muscles (EOM) in the control of eye movement has been a matter of continuous debate. These muscles have atypical sensory receptors in several species and it has been proposed that they are not supported by stretch reXexes. We recorded electromyographic activity of EOM during passive rotations of the eye in sedated rats and squirrel monkeys and observed typical stretch reXexes in these muscles. Results suggest that there is a similarity in the reXexive control of limb and eye movement, despite substantial differences in their biomechanics and sensory receptors. Like in some limb skeletal muscles, the stretch reflex in EOM in the investigated species might be mediated by other lengthsensitive receptors, rather than muscle spindles.

Referent control of action and perception

“…The presence of stretch refl exes in EOMs has directly been demonstrated by Dancause et al (2007). They recorded EMG activity of horizontal rectus muscles during passive stretches in squirrel monkeys and rats.…”

“…A major argument in support of this suggestion is that proprioceptive feedback is either absent or plays a minimal role in the control of EOMs (for review see Lennerstrand 2007 ). However, some experimental fi ndings confl ict with this suggestion ( Hayman and Donaldson 1995;Donaldson 2000 ;Dancause et al 2007 ). Moreover, the family of tension-extension characteristics of EOMs recorded in humans (Fig.…”

“…Muscle spindle receptors are present in eye muscles in humans but absent in eye muscles of squirrel monkeys and rats but other receptors that are sensitive to changes in the muscle length, most likely receptors called palisades (Dancause et al 2007 ), could be responsible for stretch refl exes in EOMs of these animals.…”

Insect Inspired Visual Motion Sensing and Flying Robots

“…• A proprioceptive sensor which is able to measure the angular position of the eye in the head or in the body. Although the question as to whether this sensor exists in the primate oculomotor system is still giving rise to some controversy, 94,95 it certainly exists in flies in the form of a pair of mechanosensitive hair fields located in the neck region. 96 The latter serves to measure and compensate for any head-body angular deviations in terms of pitch, 72 roll 73 and yaw.…”

A Vision-based Steering Control System for Aerial Vehicles

“…Although the question as to whether this sensor exists in the primate oculomotor system is still giving rise to some controversy (Clifford, Know & Dutton 2000) (Dancause et al 2007), it certainly exists in flies in the form of a pair of mechanosensitive hair fields located in the neck region (Preuss & Hengstenberg 1992), which serve to measure and compensate for any head-body angular deviations in terms of pitch (Schilstra & Hateren 1998), roll (Hengstenberg 1988) and yaw (Liske 1977). In section 2, we will describe our latest aerial robot, which has been called OSCAR II.…”