UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Slowly-Conducting Pyramidal Tract Neurons in Macaque and Rat

Kraskov, A; Soteropoulos, DS; Glover, IS; Lemon, RN; Baker, SN; (2019) Slowly-Conducting Pyramidal Tract Neurons in Macaque and Rat. Cerebral Cortex 10.1093/cercor/bhz318. (In press). Green open access

[thumbnail of Kraskov_FinalFinalText_20191126_meanADLs.pdf]
Preview
Text
Kraskov_FinalFinalText_20191126_meanADLs.pdf - Published Version

Download (1MB) | Preview

Abstract

Anatomical studies report a large proportion of fine myelinated fibers in the primate pyramidal tract (PT), while very few PT neurons (PTNs) with slow conduction velocities (CV) (<~10 m/s) are reported electrophysiologically. This discrepancy might reflect recording bias toward fast PTNs or prevention of antidromic invasion by recurrent inhibition (RI) of slow PTNs from faster axons. We investigated these factors in recordings made with a polyprobe (32 closely-spaced contacts) from motor cortex of anesthetized rats (n = 2) and macaques (n = 3), concentrating our search on PTNs with long antidromic latencies (ADLs). We identified 21 rat PTNs with ADLs >2.6 ms and estimated CV 3-8 m/s, and 67 macaque PTNs (>3.9 ms, CV 6-12 m/s). Spikes of most slow PTNs were small and present on only some recording contacts, while spikes from simultaneously recorded fast-conducting PTNs were large and appeared on all contacts. Antidromic thresholds were similar for fast and slow PTNS, while spike duration was considerably longer in slow PTNs. Most slow PTNs showed no signs of failure to respond antidromically. A number of tests, including intracortical microinjection of bicuculline (GABAA antagonist), failed to provide any evidence that RI prevented antidromic invasion of slow PTNs. Our results suggest that recording bias is the main reason why previous studies were dominated by fast PTNs.

Type: Article
Title: Slowly-Conducting Pyramidal Tract Neurons in Macaque and Rat
Location: United States
Open access status: An open access version is available from UCL Discovery
DOI: 10.1093/cercor/bhz318
Publisher version: https://doi.org/10.1093/cercor/bhz318
Language: English
Additional information: Copyright © The Author(s) 2019. Published by Oxford University Press. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
Keywords: corticospinal, macaque, monkey, pyramidal tract, rat
UCL classification: UCL
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences > UCL Queen Square Institute of Neurology
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences > UCL Queen Square Institute of Neurology > Clinical and Movement Neurosciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences > UCL Queen Square Institute of Neurology > Department of Neuromuscular Diseases
URI: https://discovery.ucl.ac.uk/id/eprint/10089070
Downloads since deposit
44Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item