Differential effects of muscimol microinjection into dorsal and ventral aspects of the premotor cortex of monkeys

Kurata, Keiko; Hoffman, Donna S.

doi:10.1152/jn.1994.71.3.1151

Cited by 191 publications

(126 citation statements)

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“…It also may be possibly involved in the eye-arm coordination required to reach for visual targets. The effect of lesions of the PMV that disturb visually guided arm movements (20) is consistent with this view. The goal-directed nature of saccades evoked in this area suggests that the PMVe may exert its control in the craniocentric coordinate rather than the retinotopic coordinate (12).…”

Section: Discussionsupporting

confidence: 75%

An oculomotor representation area within the ventral premotor cortex

Fujii

Mushiake

Tanji

1998

Proc. Natl. Acad. Sci. U.S.A.

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We explored the ventral part of the premotor cortex (PMV) with intracortical microstimulation (ICMS) while monkeys performed a visual fixation task, to see whether the PMV is involved in oculomotor control. ICMS evoked saccades from a small-restricted region in the PMV, without evoking movements in the limbs, neck, or body. We found the saccade-evoking site in the PMV in a total of three hemispheres in two monkeys. Quantitative analysis of the effects of eye position on saccades evoked by microstimulation of the PMV characterized the evoked saccades as goal directed. The nature of the saccades evoked in the PMV contrasted with the fixed vector nature of saccades evoked by ICMS of the frontal eye field. We also found that neurons in this restricted area of the PMV were active while the animals were performing a saccade task that required them to make saccades toward targets without arm movements. These data provide evidence for the presence of an oculomotor-specific subregion within the PMV. This subregion and the surrounding skeletomotorrepresenting regions of the PMV seem to coordinate oculomotor and skeletomotor control in performing goal-directed motor tasks.The ventral portion of the premotor cortex (PMV) of primates has been implicated in the sensorial guidance of arm movements (1-3). It is natural to postulate some involvement of the PMV in oculomotor control, because eye movements usually are coupled with limb movements in visually guided reaching, and oculomotor and skeletomotor performance must be coordinated. In this study, we looked for oculomotor representation in the PMV by applying intracortical microstimulation (ICMS) while monkeys performed oculomotor tasks. Interest in the issue of PMV involvement in oculomotor control has increased after a recent report by Thier and Andersen (4). They found that microstimulation of the rostral part of the intraparietal cortex (intercalated zone) elicited goal-directed saccadic eye movements, whereas microstimulation of the lateral wall of the lateral intraparietal sulcus produced constant-vector saccades. In view of the corticocortical connections between portions of the intraparietal cortex and the PMV (5), it seemed worthwhile to look for microstimulation effects in the PMV. We found a subregion within the PMV that is a low-threshold saccade-evoking area. Furthermore, we showed that neurons in this subregion are selectively active in association with voluntary, visually guided saccades.

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Section: Discussionsupporting

confidence: 75%

An oculomotor representation area within the ventral premotor cortex

Fujii

Mushiake

Tanji

1998

Proc. Natl. Acad. Sci. U.S.A.

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“…Our findings suggest that previous negative reports might have resulted from merging different learning epochs into a single experimental unit. Figure 4 B illustrates the opposite dynamics generated in dorsal premotor cortex during different learning stages, confirming that this region contributes to both initial learning and retention of arbitrary visuomotor associations (Halsband and Freund, 1990;Kurata and Hoffman, 1994;Petrides, 1997).…”

Section: Premotor Cortexmentioning

confidence: 61%

Cerebral Changes during Performance of Overlearned Arbitrary Visuomotor Associations

Grol¹,

Lange²,

Verstraten³

et al. 2006

J. Neurosci.

107

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The posterior parietal cortex (PPC) is known to be involved in the control of automatic movements that are spatially guided, such as grasping an apple. We considered whether the PPC might also contribute to the performance of visuomotor associations in which stimuli and responses are linked arbitrarily, such as producing a certain sound for a typographical character when reading aloud or pressing pedals according to the color of a traffic light when driving a motor vehicle. The PPC does not appear to be necessary for learning new arbitrary visuomotor associations, but with extensive training, the PPC can encode nonspatial sensory features of task-relevant cues. Accordingly, we have tested whether the contributions of the PPC might become apparent once arbitrary sensorimotor mappings are overlearned.We have used functional magnetic resonance imaging to measure cerebral activity while subjects were learning novel arbitrary visuomotor associations, overlearning known mappings, or attempting to learn frequently changing novel mappings. To capture the dynamic features of cerebral activity related to the learning process, we have compared time-varying modulations of activity between conditions rather than average (steady-state) responses.Frontal, striatal, and intraparietal regions showed decreasing or stable activity when subjects learned or attempted to learn novel associations, respectively. Importantly, the same frontal, striatal, and intraparietal regions showed time-dependent increases in activity over time as the mappings become overlearned, i.e., despite time-invariant behavioral responses. The automaticity of these mappings predicted the degree of intraparietal changes, indicating that the contribution of the PPC might be related to a particular stage of the overlearning process. We suggest that, as the visuomotor mappings become robust to interference, the PPC may convey relevant sensory information toward the motor cortex. More generally, our findings illustrate how rich cerebral dynamics can underlie stable behavior.

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“…We infused 2 µl of the solution over 13.5 min. These parameters were selected to be similar to those used previously (Hikosaka and Wurtz 1985;Schiller et al 1987;Munoz and Wurtz 1993;Robinson et al 1993;Kurata and Hoffman 1994;Ohtsuka et al 1994). …”

Section: Infusion Methodsmentioning

confidence: 99%

Reversible inactivation of macaque frontal eye field

1997

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The macaque frontal eye field (FEF) is involved in the generation of saccadic eye movements and fixations. To better understand the role of the FEF, we reversibly inactivated a portion of it while a monkey made saccades and fixations in response to visual stimuli. Lidocaine was infused into a FEF and neural inactivation was monitored with a nearby microelectrode. We used two saccadic tasks. In the delay task, a target was presented and then extinguished, but the monkey was not allowed to make a saccade to its location until a cue to move was given. In the step task, the monkey was allowed to look at a target as soon as it appeared. During FEF inactivation, monkeys were severely impaired at making saccades to locations of extinguished contralateral targets in the delay task. They were similarly impaired at making saccades to locations of contralateral targets in the step task if the target was flashed for ≤100 ms, such that it was gone before the saccade was initiated. Deficits included increases in saccadic latency, increases in saccadic error, and increases in the frequency of trials in which a saccade was not made. We varied the initial fixation location and found that the impairment specifically affected contraversive saccades rather than affecting all saccades made into head-centered contralateral space. Monkeys were impaired only slightly at making saccades to contralateral targets in the step task if the target duration was 1000 ms, such that the target was present during the saccade: latency increased, but increases in saccadic error were mild and increases in the frequency of trials in which a saccade was not made were insignificant. During FEF inactivation there usually was a direct correlation between the latency and the error of saccades made in response to contralateral targets. In the delay task, FEF inactivation increased the frequency of making premature saccades to ipsilateral targets. FEF inactivation had inconsistent and mild effects on saccadic peak velocity. FEF inactivation caused impairments in the ability to fixate lights steadily in contralateral space. FEF inactivation always caused an ipsiversive deviation of the eyes in darkness. In summary, our results suggest that the FEF plays major roles in (1) generating contraversive saccades to locations of extinguished or flashed targets, (2) maintaining contralateral fixations, and (3) suppressing inappropriate ipsiversive saccades.

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Differential effects of muscimol microinjection into dorsal and ventral aspects of the premotor cortex of monkeys

Cited by 191 publications

References 0 publications

An oculomotor representation area within the ventral premotor cortex

An oculomotor representation area within the ventral premotor cortex

Cerebral Changes during Performance of Overlearned Arbitrary Visuomotor Associations

Reversible inactivation of macaque frontal eye field

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