TY - JOUR
T1 - Contralateral Limb Specificity for Movement Preparation in the Parietal Reach Region
AU - Mooshagian, Eric
AU - Yttri, Eric A.
AU - Loewy, Arthur D.
AU - Snyder, Lawrence H.
N1 - Funding Information:
Received Jan. 28, 2021; revised Oct. 30, 2021; accepted Dec. 5, 2021. Author contributions: E.M., A.D.L., and L.H.S. analyzed data; E.M., E.A.Y., and L.H.S. wrote the first draft of the paper; E.M. and L.H.S. edited the paper; E.M. and L.H.S. wrote the paper; E.A.Y. and L.H.S. designed research; E.A.Y. performed research. This work was supported by National Institutes of Health Grant EY012135. All the relevant code is available upon reasonable request to the senior author. We thank Jonathon Tucker for assistance with MRI acquisition and figure construction. *E.M. and E.A.Y. contributed equally to this work. The authors declare no competing financial interests. Correspondence should be addressed to Eric Mooshagian at emooshagian@ucsd.edu. https://doi.org/10.1523/JNEUROSCI.0232-21.2021 Copyright © 2022 the authors
Publisher Copyright:
Copyright © 2022 the authors
PY - 2022/3/2
Y1 - 2022/3/2
N2 - The canonical view of motor control is that distal musculature is controlled primarily by the contralateral cerebral hemisphere; unilateral brain lesions typically affect contralateral but not ipsilateral musculature. Contralateral-only limb deficits following a unilateral lesion suggest but do not prove that control is strictly contralateral: the loss of a contribution of the lesioned hemisphere to the control of the ipsilesional limb could be masked by the intact contralateral drive from the nonlesioned hemisphere. To distinguish between these possibilities, we serially inactivated the parietal reach region, comprising the posterior portion of medial intraparietal area, the anterior portion of V6a, and portions of the lateral occipital parietal area, in each hemisphere of 2 monkeys (23 experimental sessions, 46 injections total) to evaluate parietal reach region’s contribution to the contralateral reaching deficits observed following lateralized brain lesions. Following unilateral inactivation, reach reaction times with the contralesional limb were slowed compared with matched blocks of control behavioral data; there was no effect of unilateral inactivation on the reaction time of either ipsilesional limb reaches or saccadic eye movements. Following bilateral inactivation, reaching was slowed in both limbs, with an effect size in each no different from that produced by unilateral inactivation. These findings indicate contralateral organization of reach preparation in posterior parietal cortex.
AB - The canonical view of motor control is that distal musculature is controlled primarily by the contralateral cerebral hemisphere; unilateral brain lesions typically affect contralateral but not ipsilateral musculature. Contralateral-only limb deficits following a unilateral lesion suggest but do not prove that control is strictly contralateral: the loss of a contribution of the lesioned hemisphere to the control of the ipsilesional limb could be masked by the intact contralateral drive from the nonlesioned hemisphere. To distinguish between these possibilities, we serially inactivated the parietal reach region, comprising the posterior portion of medial intraparietal area, the anterior portion of V6a, and portions of the lateral occipital parietal area, in each hemisphere of 2 monkeys (23 experimental sessions, 46 injections total) to evaluate parietal reach region’s contribution to the contralateral reaching deficits observed following lateralized brain lesions. Following unilateral inactivation, reach reaction times with the contralesional limb were slowed compared with matched blocks of control behavioral data; there was no effect of unilateral inactivation on the reaction time of either ipsilesional limb reaches or saccadic eye movements. Following bilateral inactivation, reaching was slowed in both limbs, with an effect size in each no different from that produced by unilateral inactivation. These findings indicate contralateral organization of reach preparation in posterior parietal cortex.
KW - intraparietal sulcus
KW - muscimol
KW - posterior parietal cortex
KW - reach
KW - visuomotor
UR - http://www.scopus.com/inward/record.url?scp=85125681958&partnerID=8YFLogxK
U2 - 10.1523/JNEUROSCI.0232-21.2021
DO - 10.1523/JNEUROSCI.0232-21.2021
M3 - Article
C2 - 34996817
AN - SCOPUS:85125681958
VL - 42
SP - 1692
EP - 1701
JO - Journal of Neuroscience
JF - Journal of Neuroscience
SN - 0270-6474
IS - 9
ER -