TY - JOUR
T1 - The raccoon lateral cervical nucleus
T2 - A single-unit analysis
AU - Simone, D. A.
AU - Pubols, B. H.
PY - 1991/1/1
Y1 - 1991/1/1
N2 - Properties of 90 lateral cervical nucleus (LCN) neurons responsive to light tactile stimulation of ipsilateral body surfaces were examined in pentobarbital sodium-anesthetized raccoons. Peripheral receptive fields (RFs) of 60 of these lay totally or partially on glabrous skin of the forepaw. There were 71 neurons antidromically activated from the contralateral thalamic ventrobasal complex (VB) or medial lemniscus. Results were compared with previous findings in the raccoon spinocervical tract (SCT) and the dorsal column-medial lemniscal system (DC-MLS). RFs located on glabrous skin of the digits were significantly smaller than those located on glabrous skin of the palm. All RFs, whether on glabrous skin of the forepaw or elsewhere, tended to be larger than those of either SCT or DC-MLS neurons. LCN units with glabrous forepaw RFs tended to be located ventrally within the nucleus. Of those LCN neurons for which the RFs lay totally or partially on glabrous skin of the forepaw, relative numbers that were rapidly adapting (RA; 77%) versus slowly adapting (SA; 23%) were comparable with those found in the SCT and in VB. Relative numbers of LCN neurons that were classed as light touch (87%) versus multireceptive (13%) were comparable with those found in the SCT. In contrast to both the SCT and VB, but in common with the prethalamic DC-MLS, indentation velocity coding functions of both RA and SA units fell within homogeneous groupings, power function exponents for RA units tending to be steeper than those for SA units (range of b = 0.710 - 0.919 vs. 0.448 - 0.883). It is concluded that the raccoon spinocervicothalamic system (SCTS) as a whole lacks the 'modality and place specificity' associated with the DC-MLS. Although the SCTS probably makes significant contributions to properties of VB neurons, these properties primarily reflect those of neurons of the DC-MLS.
AB - Properties of 90 lateral cervical nucleus (LCN) neurons responsive to light tactile stimulation of ipsilateral body surfaces were examined in pentobarbital sodium-anesthetized raccoons. Peripheral receptive fields (RFs) of 60 of these lay totally or partially on glabrous skin of the forepaw. There were 71 neurons antidromically activated from the contralateral thalamic ventrobasal complex (VB) or medial lemniscus. Results were compared with previous findings in the raccoon spinocervical tract (SCT) and the dorsal column-medial lemniscal system (DC-MLS). RFs located on glabrous skin of the digits were significantly smaller than those located on glabrous skin of the palm. All RFs, whether on glabrous skin of the forepaw or elsewhere, tended to be larger than those of either SCT or DC-MLS neurons. LCN units with glabrous forepaw RFs tended to be located ventrally within the nucleus. Of those LCN neurons for which the RFs lay totally or partially on glabrous skin of the forepaw, relative numbers that were rapidly adapting (RA; 77%) versus slowly adapting (SA; 23%) were comparable with those found in the SCT and in VB. Relative numbers of LCN neurons that were classed as light touch (87%) versus multireceptive (13%) were comparable with those found in the SCT. In contrast to both the SCT and VB, but in common with the prethalamic DC-MLS, indentation velocity coding functions of both RA and SA units fell within homogeneous groupings, power function exponents for RA units tending to be steeper than those for SA units (range of b = 0.710 - 0.919 vs. 0.448 - 0.883). It is concluded that the raccoon spinocervicothalamic system (SCTS) as a whole lacks the 'modality and place specificity' associated with the DC-MLS. Although the SCTS probably makes significant contributions to properties of VB neurons, these properties primarily reflect those of neurons of the DC-MLS.
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U2 - 10.1152/jn.1991.65.6.1411
DO - 10.1152/jn.1991.65.6.1411
M3 - Article
C2 - 1875250
AN - SCOPUS:0025832893
SN - 0022-3077
VL - 65
SP - 1411
EP - 1421
JO - Journal of neurophysiology
JF - Journal of neurophysiology
IS - 6
ER -