RT Journal Article
SR Electronic
T1 Partial Peripheral Nerve Injury Promotes a Selective Loss of GABAergic Inhibition in the Superficial Dorsal Horn of the Spinal Cord
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 6724
OP 6731
DO 10.1523/JNEUROSCI.22-15-06724.2002
VO 22
IS 15
A1 Moore, Kimberly A.
A1 Kohno, Tatsuro
A1 Karchewski, Laurie A.
A1 Scholz, Joachim
A1 Baba, Hiroshi
A1 Woolf, Clifford J.
YR 2002
UL http://www.jneurosci.org/content/22/15/6724.abstract
AB To clarify whether inhibitory transmission in the superficial dorsal horn of the spinal cord is reduced after peripheral nerve injury, we have studied synaptic transmission in lamina II neurons of an isolated adult rat spinal cord slice preparation after complete sciatic nerve transection (SNT), chronic constriction injury (CCI), or spared nerve injury (SNI). Fast excitatory transmission remains intact after all three types of nerve injury. In contrast, primary afferent-evoked IPSCs are substantially reduced in incidence, magnitude, and duration after the two partial nerve injuries, CCI and SNI, but not SNT. Pharmacologically isolated GABAAreceptor-mediated IPSCs are decreased in the two partial nerve injury models compared with naive animals. An analysis of unitary IPSCs suggests that presynaptic GABA release is reduced after CCI and SNI. Partial nerve injury also decreases dorsal horn levels of the GABA synthesizing enzyme glutamic acid decarboxylase (GAD) 65 kDa ipsilateral to the injury and induces neuronal apoptosis, detected by terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling staining in identified neurons. Both of these mechanisms could reduce presynaptic GABA levels and promote a functional loss of GABAergic transmission in the superficial dorsal horn.