Watching deep-brain movement circuits in action
Measuring the activity of specific neuronal subtypes in the brain during performance of complex behaviors has proven difficult, as identifying different neurons during electrophysiological recordings is cumbersome, and using microscopes to view neurons constrains the range of behaviors that can be analyzed.
IRP researchers Guohong Cui, M.D., Ph.D., David M. Lovinger, Ph.D., Steven S. Vogel, Ph.D., and Rui Costa, D.V.M., Ph.D., used a novel optogenetic approach with small fiber-optic implants to measure the activity of two separate neural types in a brain region called the striatum, part of the basal ganglia. They discovered that these different types of neurons are co-active during the initiation of bodily movement sequences, contrary to the long-standing theory that one neuron activates sequences while another terminates them.
Development of deep-brain fiber-optic photometry is bringing previously inaccessible regions of brain circuitry into view for more detailed experimental observation of behaviors. Finding the co-activity of these two sets of neurons impacts the model of basal ganglia function and may influence the treatment of disorders originating within the brain’s striatum, including Parkinson’s and Huntington’s diseases.
Cui, G., Jun, S.B., Jin, X., Pham, M.D., Vogel, S.S., Lovinger, D.M. and Costa, R.M. (2013). Concurrent activation of striatal direct and indirect pathways during action initiation. Nature. 494(7436): 238-242.
Cui, G., Jun, S.B., Jin, X., Luo, G., Pham, M.D., Lovinger, D.M., Vogel, S.S., and Costa, RM. (2014). Deep brain optical measurements of cell type-specific neural activity in behaving mice. Nature Protocols. 9(6):1213-1228.