Journal article
Terminal organization of the corticospinal projection from the lateral premotor cortex to the cervical enlargement (C5–T1) in rhesus monkey
Journal of comparative neurology (1911), Vol.527(16), pp.2761-2789
11/01/2019
DOI: 10.1002/cne.24706
PMCID: PMC6721988
PMID: 31032921
Abstract
ABSTRACT
High‐resolution tract tracing and stereology were used to study the terminal organization of the corticospinal projection (CSP) from the ventral (v) and dorsal (d) regions of the lateral premotor cortex (LPMC) to spinal levels C5–T1. The LPMCv CSP originated from the postarcuate sulcus region, was bilateral, sparse, and primarily targeted the dorsolateral and ventromedial sectors of contralateral lamina VII. The convexity/lateral part of LPMCv did not project below C2. Thus, very little LPMCv corticospinal output reaches the cervical enlargement. In contrast, the LPMCd CSP was 5× more prominent in terminal density. Bilateral terminal labeling occurred in the medial sectors of lamina VII and adjacent lamina VIII, where propriospinal neurons with long‐range bilateral axon projections reside. Notably, lamina VIII also harbors axial motoneurons. Contralateral labeling occurred in the lateral sectors of lamina VII and the dorsomedial quadrant of lamina IX, noted for harboring proximal upper limb flexor motoneurons. Segmentally, the CSP to contralateral laminae VII and IX preferentially innervated C5–C7, which supplies shoulder, elbow, and wrist musculature. In contrast, terminations in axial‐related lamina VIII were distributed bilaterally throughout all cervical enlargement levels, including C8 and T1. These findings demonstrate the LPMCd CSP is structured to influence axial and proximal upper limb movements, supporting Kuypers conceptual view of the LPMCd CSP being a major component of the medial motor control system. Thus, distal upper extremity control influenced by LPMC, including grasping and manipulation, must occur through indirect neural network connections such as corticocortical, subcortical, or intrinsic spinal circuits.
Using high‐resolution tract tracing, the authors demonstrate the dorsal lateral premotor cortex (LPMCd) gives rise to a prominent bilateral corticospinal projection (CSP) involving the ventromedial (red) and lateral (blue) gray matter regions. In contrast a weaker bilateral CSP arose from the peri‐arcuate region of ventral lateral premotor cortex (LPMCv).
Details
- Title: Subtitle
- Terminal organization of the corticospinal projection from the lateral premotor cortex to the cervical enlargement (C5–T1) in rhesus monkey
- Creators
- Robert J Morecraft - The University of South Dakota, Sanford School of MedicineJizhi Ge - The University of South Dakota, Sanford School of MedicineKim S Stilwell‐Morecraft - The University of South Dakota, Sanford School of MedicineDiane L Rotella - The University of IowaMarc A Pizzimenti - The University of IowaWarren G Darling - The University of Iowa
- Resource Type
- Journal article
- Publication Details
- Journal of comparative neurology (1911), Vol.527(16), pp.2761-2789
- DOI
- 10.1002/cne.24706
- PMID
- 31032921
- PMCID
- PMC6721988
- NLM abbreviation
- J Comp Neurol
- ISSN
- 0021-9967
- eISSN
- 1096-9861
- Publisher
- John Wiley & Sons, Inc; Hoboken, USA
- Number of pages
- 29
- Grant note
- National Institutes of Health (NS 33003; NS 046367; NS 097450)
- Language
- English
- Date published
- 11/01/2019
- Academic Unit
- Anatomy and Cell Biology; Physical Therapy and Rehabilitation Science; Health, Sport, and Human Physiology
- Record Identifier
- 9984025412802771
Metrics
78 Record Views