Activity-Dependent Neuron-Glial Communication
The importance of neural impulses in regulating nervous system
development is well recognized, but much less is known about possible
activity-dependent regulation of nonneuronal cells (glia). These
cells provide essential structural and functional support for
developing and adult neurons. More recent research indicates that
glia can communicate among themselves and interact with neurons
to control synaptic transmission, and synaptogenesis. Our work
has shown that neural impulses in DRG axons (far removed from
synapses) can be detected by all types of glia, including Schwann
cells and oligodendrocytes, which form myelin in the PNS and CNS
(respectively). Using calcium imaging, molecular methods and functional
assays, this work has identified extracellular ATP and similar
purinergic signaling molecules in the signaling between axons
and myelinating glia. We are working to identify the membrane
receptors and intracellular signaling pathways activated by this
axon-glial signaling, and finding that a number of genes in glial
cells are regulated by action potential firing. This work shows
that proliferation, differentiation, and myelination of Schwann
cells and oligodendrocytes can be regulated by action potential
firing through the release of ATP from premyelinated axons.