Optogenetics offers a unique method to regulate the activity of select neural circuits. However, the electrophysiological consequences of targeted optogenetic manipulation upon the entire circuit remain poorly understood. Analysis of the sensory-CNS-motor circuit in Drosophila larvae expressing eHpHR and ChR2-XXL revealed unexpected patterns of excitability. Optical stimulation of motor neurons targeted to express eNpHR resulted in inhibition followed by excitation of body wall contraction with repetitive stimulation in intact larvae. In situ preparations with direct electrophysiological measures showed an increased responsiveness to excitatory synaptic activity induced by sensory stimulation within a functional neural circuit. To ensure proper function of eNpHR and ChR2-XXL they were expressed in body wall muscle and direct electrophysiological measurements were obtained. Under eNpHR induced hyperpolarization the muscle remained excitable with increased amplitude of excitatory postsynaptic synaptic potentials. Theoretical models to explain the observations are presented. This study aids in increasing the understanding of the varied possible influences with light activated proteins within intact neural circuits.
|State||Published - Jul 2018|
Bibliographical noteFunding Information:
KW had a summer fellowship from DADD: German Academic Exchange Service, RISE - Program (Research Internships in Science and Engineering) to work in the USA on this project. RLC received funding from the Kentucky Science and Engineering Foundation (KSEF-3712-RDE-019) at the Kentucky Science and Technology Corporation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
© 2018 Mattingly et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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