TY - JOUR
T1 - Subthreshold oscillations induced by spinal nerve injury in dissociated muscle and cutaneous afferents of mouse DRG
AU - Liu, Chang Ning
AU - Devor, Marshall
AU - Waxman, Stephen G.
AU - Kocsis, Jeffery D.
PY - 2002
Y1 - 2002
N2 - Whole cell patch-clamp recordings were obtained from dissociated mouse lumbar dorsal root ganglion (DRG) neurons. Recordings were made from control neurons and neurons axotomized by transection of the corresponding spinal nerve 1-2 days prior to dissociation. Medium to large muscle and cutaneous afferent neurons were identified by retrograde transport of True Blue or Fluoro-Gold injected into the corresponding peripheral tissue. Action potentials were classified as non-inflected spikes (AO) and inflected spikes (Ainf). High-frequency, low-amplitude subthreshold membrane potential oscillations were observed in 8% of control Ao neurons, but their incidence increased to 31% in the nerve injury group. Fifty percent of axotomized muscle afferent AO cells displayed oscillations, while 26% of axotomized cutaneous afferents exhibited oscillations. Lower-frequency oscillations were also observed in a small fraction (4%) of Ainf neurons on strong depolarization. Their numbers were increased after the nerve injury, but the difference was not statistically significant. The oscillations often triggered burst firing in distinct patterns of action potential activity. These results indicate that injury-induced membrane oscillations of DRG neurons, previously observed in whole DRG of rats, are present in dissociated DRG neurons of the adult mouse. Moreover, these observations indicate that both muscle and cutaneous afferents in the Aβ size range give rise to injury-induced membrane oscillations, with muscle afferents being more prone to develop oscillations.
AB - Whole cell patch-clamp recordings were obtained from dissociated mouse lumbar dorsal root ganglion (DRG) neurons. Recordings were made from control neurons and neurons axotomized by transection of the corresponding spinal nerve 1-2 days prior to dissociation. Medium to large muscle and cutaneous afferent neurons were identified by retrograde transport of True Blue or Fluoro-Gold injected into the corresponding peripheral tissue. Action potentials were classified as non-inflected spikes (AO) and inflected spikes (Ainf). High-frequency, low-amplitude subthreshold membrane potential oscillations were observed in 8% of control Ao neurons, but their incidence increased to 31% in the nerve injury group. Fifty percent of axotomized muscle afferent AO cells displayed oscillations, while 26% of axotomized cutaneous afferents exhibited oscillations. Lower-frequency oscillations were also observed in a small fraction (4%) of Ainf neurons on strong depolarization. Their numbers were increased after the nerve injury, but the difference was not statistically significant. The oscillations often triggered burst firing in distinct patterns of action potential activity. These results indicate that injury-induced membrane oscillations of DRG neurons, previously observed in whole DRG of rats, are present in dissociated DRG neurons of the adult mouse. Moreover, these observations indicate that both muscle and cutaneous afferents in the Aβ size range give rise to injury-induced membrane oscillations, with muscle afferents being more prone to develop oscillations.
UR - http://www.scopus.com/inward/record.url?scp=0036095984&partnerID=8YFLogxK
U2 - 10.1152/jn.00705.2001
DO - 10.1152/jn.00705.2001
M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???
AN - SCOPUS:0036095984
SN - 0022-3077
VL - 87
SP - 2009
EP - 2017
JO - Journal of Neurophysiology
JF - Journal of Neurophysiology
IS - 4
ER -