Spared Premotor Areas Undergo Rapid Nonlinear Changes in Functional Organization following a Focal Ischemic Infarct in Primary Motor Cortex of Squirrel Monkeys

Erik J. Plautz, Scott Barbay, Shawn B. Frost, Ann M. Stowe, Numa Dancause, Elena V. Zoubina, Ines Eisner-Janowicz, David J. Guggenmos, Randolph J. Nudo

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

Recovery of motor function after stroke is accompanied by reorganization of movement representations in spared cortical motor regions. It is widely assumed that map reorganization parallels recovery, suggesting a causal relationship. We examined this assumption by measuring changes in motor representations in eight male and six female squirrel monkeys in the first few weeks after injury, a time when motor recovery is most rapid. Maps of movement representations were derived using intracortical microstimulation techniques in primary motor cortex (M1), ventral premotor cortex (PMv), and dorsal premotor cortex (PMd) in 14 adult squirrel monkeys before and after a focal infarct in the M1 distal forelimb area. Maps were derived at baseline and at either 2 (n = 7) or 3 weeks (n = 7) postinfarct. In PMv the forelimb maps remained unchanged at 2 weeks but contracted significantly (-42.4%) at 3 weeks. In PMd the forelimb maps expanded significantly (1110.6%) at 2 weeks but contracted significantly (-57.4%) at 3 weeks. Motor deficits were equivalent at both time points. These results highlight two features of plasticity after M1 lesions. First, significant contraction of distal forelimb motor maps in both PMv and PMd is evident by 3 weeks. Second, an unpredictable nonlinear pattern of reorganization occurs in the distal forelimb representation in PMd, first expanding at 2 weeks, and then contracting at 3 weeks postinjury. Together with previous results demonstrating reliable map expansions in PMv several weeks to months after M1 injury, the subacute time period may represent a critical window for the timing of therapeutic interventions.

Original languageEnglish
Pages (from-to)2021-2032
Number of pages12
JournalJournal of Neuroscience
Volume43
Issue number11
DOIs
StatePublished - Mar 15 2023

Bibliographical note

Publisher Copyright:
Copyright © 2023 the authors.

Keywords

  • ICMS
  • cortical plasticity
  • motor maps
  • premotor cortex
  • recovery of function
  • stroke

ASJC Scopus subject areas

  • General Neuroscience

Fingerprint

Dive into the research topics of 'Spared Premotor Areas Undergo Rapid Nonlinear Changes in Functional Organization following a Focal Ischemic Infarct in Primary Motor Cortex of Squirrel Monkeys'. Together they form a unique fingerprint.

Cite this