Topography of supplementary eye field afferents to frontal eye field in macaque: Implications for mapping between saccade coordinate systems

Abstract

Two discrete areas in frontal cortex are involved in generating saccadic eye movements -the frontal eye field (FEF) and the supplementary eye field (SEF). Whereas FEF represents saccades in a topographic retinotopic map, recent evidence indicates that saccades may be represented craniotopically in SEF. To further investigate the relationship between these areas, the topographic organization of afferents to FEF from SEF in Macaca mulatto was examined by placing injections of distinct retrograde tracers into different parts of FEF that represented saccades of different amplitudes. Central FEF (lateral area 8A), which represents saccades of intermediate amplitudes, received afferents from a larger portion of SEF than did lateral FEF (area 45), which represents shorter saccades, or medial FEF (medial area 8A), which represents the longest saccades in addition to pinna movements. Moreover, in every case the zone in SEF that innervated lateral FEF (area 45) also projected to medial FEF (area 8A). In one case, a zone in rostral SEF projected to both lateral area 8A from which eye movements were evoked by microstimulation as well as medial area 8A from which pinna movements were elicited by microstimulation. This pattern of afferent convergence and divergence from SEF onto the retinotopic saccade map in FEF is indicative of some sort of map transformation between SEF and FEF. Such a transformation would be necessary to interconnect a topographic craniotopic saccade representation in SEF with a topographic retinotopic saccade representation in FEF.

Recruitment of a contralateral head turning synergy by stimulation of monkey supplementary eye fields

“…Anatomical studies suggest a number of alternatives for how a command evoked by SEF stimulation can get to oculomotor and cephalomotor structures. The SEF has connections with numerous cortical oculomotor areas including the FEF and also projects to the intermediate and deep layers of the SC, the caudate, and other targets within the brain stem (Huerta and Kaas 1990;Parthasarathy et al 1992;Schall et al 1993;Shook et al 1990Shook et al , 1991. Such diverse projections, when considered alongside the prolonged neck muscle response latencies we have observed (particularly compared with the FEF), hinder our ability to draw conclusions about the pathway or pathways mediating the evoked neck muscle responses.…”

Reversible inactivation of macaque dorsomedial frontal cortex: effects on saccades and fixations

“…Consequently, a stimulation map of termination zones exists in DMFC that corresponds to the topography of fixation cell tuning (Tehovnik and Lee 1993;Lee and Tehovnik 1995). These results suggest that DMFC uses a place code for saccades, signaling the desired final position of the eyes (Schlag and Schlag-Rey 1987;Mann et al 1988;Schall 1991b;Schall et al 1993;Lee and Tehovnik 1995).…”

Oculomotor Areas of the Primate Frontal Lobes: A Transneuronal Transfer of Rabies Virus and [14C]-2-Deoxyglucose Functional Imaging Study

“…This corresponds to the region of the superior frontal gyrus projecting to the FEF (24 mm 2 ) (Schall et al, 1993). The territory occupied by labeled neurons is slightly bigger than the SEF described by Russo and Bruce (2000) but considerably smaller than that described by Tehovnik et al (1993).…”