RT Journal Article
SR Electronic
T1 Muscle Spindle-Derived Neurotrophin 3 Regulates Synaptic Connectivity between Muscle Sensory and Motor Neurons
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 3512
OP 3519
DO 10.1523/JNEUROSCI.22-09-03512.2002
VO 22
IS 9
A1 Hsiao-Huei Chen
A1 Warren G. Tourtellotte
A1 Eric Frank
YR 2002
UL http://www.jneurosci.org/content/22/9/3512.abstract
AB Ia afferents induce the formation of muscle spindles prenatally and maintain them postnatally. To address whether spindles, in turn, regulate the function of Ia afferents, we examined Egr3-null mutant mice (Egr3−/−), in which muscle spindles degenerate progressively after birth. Egr3−/− mice develop gait ataxia, scoliosis, resting tremors, and ptosis, suggesting a defect in proprioception. Despite the normal morphological appearance of peripheral and central sensory projections, we observed a profound functional deficit in the strength of sensory–motor connections in Egr3−/− mice. Muscle spindles in Egr3−/− mice do not express NT3. Intramuscular injections of NT3 to Egr3−/− mice during the postnatal period restored sensory–motor connections. Thus, NT3 derived from muscle spindles regulates the synaptic connectivity between muscle sensory and motor neurons.