Frontal ‘oculomotor’ area in alert cat. II. Unit discharges associated with eye movements and neck muscle activity

Dissociation of Eye and Head Components of Gaze Shifts by Stimulation of the Omnipause Neuron Region

“…Evidence supporting the notion of a head-movement command, not necessarily associated with a gaze shift, comes from neural recordings in the superior colliculus , central mesencephalic reticular formation (Pathmanathan et al 2006a,b), microstimulation of the frontal and supplementary eye fields (Chen 2006;Chen and Walton 2005), and adaptation of eye-head coordination in the context of a limited visual field (Constantin et al 2004). Neural signals encoding a desired gaze-displacement command have been proposed to exist at the level of the superior colliculus (Freedman and Sparks 1997a;Freedman et al 1996;Klier et al 2001;Munoz et al 1991), frontal eye field (Guitton and Mandl 1978;Knight and Fuchs 2007;Tu and Keating 2000;but see Chen 2006 for an alternative hypothesis), and supplementary eye field (Chen and Walton 2005;Martinez-Trujillo et al 2003). The ⌬G d command, perhaps after some processing that incorporates the effect of the eye position in the orbits and the location of the stimulus (Freedman 2001), adds to the neck muscle drive at the level of the pontine burst generator (BG).…”

Monocular eye movement in the cat: Its corticotectal pathway.

“…Conjugate eye movements have been reported in many experiments describing evoked eye movements following cortical stimulation of the brain (LEMMEN et al, 1959;ROBINSON and FUCHS, 1969;SCHLAG and SCHLAG-REY, 1970;GUITTON and MANDL, 1978). On the other hand, we reported monocular movements of the contralateral eye following cortical stimulation in the fundus of the coronal sulcus (CORo) of the cat (TAMAI et al, 1984).…”

“…On the other hand, we reported monocular movements of the contralateral eye following cortical stimulation in the fundus of the coronal sulcus (CORo) of the cat (TAMAI et al, 1984). The CORo is quite different, with respect to the latency and type of the eye movement, from areas previously described as classical frontal oculomotor areas (FOA) in the cat: the medial wall of the hemisphere under the cruciate sulcus and the medial and lateral banks of the presylvian sulcus (SCHLAG and SCHLAG-REY, 1970;GUITTON and MANDL, 1978). Therefore, it is of interest to know whether the CORo has its own direct projection to the subcortical structure related to the eye movements.…”

Frontal projections of dorsal neck and extraocular muscles

“…Contraction of the suboccipital group results in small head movements, and Granit (27) has suggested that these muscles can play an important role in head stabilization, a necessary condition for appropriate function of the distance receptors (51). Those results and the difference in latencies, shorter in presylvian than in pericruciate zones, suggest that presylvian fields may be involved, although not exclusively, with fine control of head position (30).…”

“…Experimental studies have disclosed that afferents from dorsal neck muscles project to various central brain areas (1,2,6,17,18,28,54) and that in the superior colliculus (2) and in the nucleus prepositus hypoglossi (28) these afferents converge with visual and extraocular muscle afferents; this suggests an involvement of these regions in the control of coordinated eye-head movements. The possibility of afferent input from dorsal neck and extraocular muscles to frontal regions known to be involved in eye and head movement in cats (29)(30)(31)50) has not received much specific attention as yet.…”