RT Journal Article
SR Electronic
T1 Differential Expression of the p75 Nerve Growth Factor Receptor in Glia and Neurons of the Rat Dorsal Root Ganglia after Peripheral Nerve Transection
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 2901
OP 2911
DO 10.1523/JNEUROSCI.16-09-02901.1996
VO 16
IS 9
A1 Xin-Fu Zhou
A1 Robert A. Rush
A1 Elspeth M. McLachlan
YR 1996
UL http://www.jneurosci.org/content/16/9/2901.abstract
AB Sympathetic nerve terminals on blood vessels within the dorsal root ganglia sprout after sciatic nerve lesions in the rat. The mechanism underlying this phenomenon is not clear, but might be predicted to involve nerve growth factor or its homologs because these factors are known to trigger collateral sprouting of undamaged sympathetic noradrenergic terminals. We have found that sciatic nerve lesions lead to a decreased expression of neuronal p75, the low-affinity receptor for the neurotrophins, but an increased expression of glial p75 in ipsilateral dorsal root ganglia. Intriguingly, the increased expression of p75 was found primarily in association with glia surrounding large-diameter neurons, which are those associated with the noradrenergic sprouts. A smaller but significant glial response was also found in contralateral ganglia. The glial response in ipsilateral ganglia could be mimicked by ventral, but not dorsal, root transection. The dorsal root lesion-induced glial responses in contralateral ganglia were greater than those induced by ventral root or sciatic nerve lesions. Combined lesions of dorsal root and either ventral root or sciatic nerve did not prevent the glial responses of ipsilateral ganglia, suggesting that a peripheral signal is involved. Colocalization studies indicate that tyrosine hydroxylase-immunoreactive nerve sprouts were associated with p75-immunoreactive glial cells. Thus, increased glial synthesis of p75 might provide an explanation for the abnormal growth of sympathetic fibers in dorsal root ganglia after peripheral nerve injury.