Florida researchers refine 'optogenetics'

Researchers from Jupiter, Florida’s Max Planck Institute for Neuroscience have developed a refinement on a common optogenetic technique, according to a study published in Neuro. By corralling light-sensitive molecules in the cell body of neurons, they increased the accuracy of optogenetic analysis of neural networks.

Optogenetics is a field that allows scientists to alter individual neurons in living tissue and monitor those manipulations in real time. Light-sensitive molecules have been inserted into neurons, and researchers can study their function by turning them on and off with light and examining the results.

“Much of optogenetics research is borne out a desire to characterize connectivity patterns in the face of genetic perturbations,” said research scientist Christopher Baker, PhD.

By comparing the neural networks of both healthy and disordered patients, researchers hope to unlock how specific circuits are altered in conditions like autism.

Stimulation of the neurons occurs via a disc-shaped point of light deep within tissue; as such, the light itself must be relatively strong. However, neural tissue is dense. The axons and dendrites of neurons can be tangled around the bodies of others in a thicket of material, explained Baker. This can cause neighboring neurons to be activated by light when only one activation is required for the experiment.

To avoid unwanted activation, Baker and other researchers spatially restricted the light sensitive molecules to the cell body, ensuring that any recorded responses can be attributed to the intended cell. It actually improved the neurons’ response to light stimulation, possibly because of the smaller volume that the light-sensitive molecules inhabit.

Utilization of this single-neuron resolution technique could allow scientists to learn how neural circuits are disturbed by disorders, and possibly lead to customized therapies for patients. However, the ideal result would be finding some common change among a population of diseased subjects, allowing for a generalized treatment, according to Baker.