Movement initiation and grasp representation in premotor and primary motor cortex mirror neurons
Abstract
Pyramidal tract neurons (PTNs) within macaque rostral ventral premotor cortex (F5) and primary motor cortex (M1) provide direct input to spinal circuitry and are critical for skilled movement control. Contrary to initial hypotheses, they can also be active during action observation, in the absence of any movement. A population-level understanding of this phenomenon is currently lacking. We recorded from single neurons, including identified PTNs, in M1 (n=187), and area F5 (n=115) as two adult male macaques executed, observed, or withheld (NoGo) reach-to-grasp actions. F5 maintained a similar representation of grasping actions during both execution and observation. In contrast, although many individual M1 neurons were active during observation, M1 population activity was distinct from execution, and more closely aligned to NoGo activity, suggesting this activity contributes to withholding of self-movement. M1 and its outputs may dissociate the initiation of movement from the representation of grasp in order to flexibly guide behaviour.
Data availability
Matlab codes and data to reproduce Figures 5-7 and Figure 9 are publicly available at https://github.com/sjjerjian/grasp-mirror-neurons.
Article and author information
Author details
Funding
Wellcome (102849/Z/13/Z)
- Alexander Kraskov
Brain Research Trust
- Steven Jack Jerjian
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: All procedures were designed to minimize discomfort and pain of the animals and were approved by the local Animal Ethics and Welfare Committee and carried out in accordance with the UK Animals (Scientific Procedures) Act (Project Licence 708254). Experiments involved two adult purpose-bred male monkeys (Macaca mulatta, M48 and M49, weighing 12.0kg and 10.5kg, respectively). The monkeys were single-housed based on veterinary advice, in a unit with other rhesus monkeys, with natural light and access to an exercise pen and forage area. Both monkeys gained weight regularly throughout the procedure.
Copyright
© 2020, Jerjian et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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