TY - JOUR
T1 - The long-latency component of cerebral evoked potentials in anesthetized cats
AU - Lee, K. H.
AU - Kim, J.
AU - Chung, J. M.
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 1986
Y1 - 1986
N2 - A late component of the cortical evoked potential elicited by somatosensory afferent input was studied in cats anesthetized with α-chloralose. Cortical evoked potentials were recorded from the somatosensory-motor cortex during stimulation of the sural nerve with graded intensities. The stimulus intensity was adjusted to activate Aαβ fibers only, then both Aαβ and Aδ fibers, and both A and C fibers, as judged by afferent volleys monitored from the sural nerve proximal to the stimulating site. In addition to early components reported previously, a very late component was identified at a latency of 400 to 600 msec following stimulation of the sural nerve with intensities above threshold for Aδ fibers. A further increase in stimulation intensity to include activation of C fibers did not reveal any more components. This late component was depressed by a systemic intravenous injection of morphine (2 mg/kg), and intravenous naloxone (0.1 mg/kg) reversed the effect of morphine. The late component of the evoked potential could also be recorded from subcortical tissue after decortication of the sensorimotor cortex. From these results, it appears that a very late component of the cortical evoked potential can be recorded from cats anesthetized with α-chloralose. The late component is evoked by activation of peripheral Aδ fibers. Furthermore, its morphine sensitivity suggests that this component may be elicited by nociceptive afferent fibers. If further investigations prove this, the late component, which is analogous to human long-latency potentials, could be used in an experimental model for pain research
AB - A late component of the cortical evoked potential elicited by somatosensory afferent input was studied in cats anesthetized with α-chloralose. Cortical evoked potentials were recorded from the somatosensory-motor cortex during stimulation of the sural nerve with graded intensities. The stimulus intensity was adjusted to activate Aαβ fibers only, then both Aαβ and Aδ fibers, and both A and C fibers, as judged by afferent volleys monitored from the sural nerve proximal to the stimulating site. In addition to early components reported previously, a very late component was identified at a latency of 400 to 600 msec following stimulation of the sural nerve with intensities above threshold for Aδ fibers. A further increase in stimulation intensity to include activation of C fibers did not reveal any more components. This late component was depressed by a systemic intravenous injection of morphine (2 mg/kg), and intravenous naloxone (0.1 mg/kg) reversed the effect of morphine. The late component of the evoked potential could also be recorded from subcortical tissue after decortication of the sensorimotor cortex. From these results, it appears that a very late component of the cortical evoked potential can be recorded from cats anesthetized with α-chloralose. The late component is evoked by activation of peripheral Aδ fibers. Furthermore, its morphine sensitivity suggests that this component may be elicited by nociceptive afferent fibers. If further investigations prove this, the late component, which is analogous to human long-latency potentials, could be used in an experimental model for pain research
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U2 - 10.3171/jns.1986.65.3.0392
DO - 10.3171/jns.1986.65.3.0392
M3 - Article
C2 - 3734889
AN - SCOPUS:0022539735
SN - 0022-3085
VL - 65
SP - 392
EP - 397
JO - Journal of neurosurgery
JF - Journal of neurosurgery
IS - 3
ER -