Cortical cells integrate synaptic input from multiple sources, but how these different inputs are distributed across individual neurons is largely unknown. Differences in input might account for diverse responses in neighboring neurons during behavior. We present a strategy for comparing the strengths of multiple types of input onto the same neuron. We developed methods for independent dualchannel photostimulation of synaptic inputs using ChR2 together with ReaChR, a red-shifted channelrhodopsin. We used dual-channel photostimulation to probe convergence of sensory information in the mouse primary motor cortex. Input from somatosensory cortex and thalamus converges in individual neurons. Similarly, inputs from distinct somatotopic regions of the somatosensory cortex are integrated at the level of single motor cortex neurons. We next developed a ReaChR transgenic mouse under the control of both Flp- and Cre-recombinases that is an effective tool for circuit mapping. Our approach to dual-channel photostimulation enables quantitative comparison of the strengths of multiple pathways across all length scales of the brain.

Item Type:	Refereed Article
Keywords:	circuit mapping, dual-channel stimulation, motor cortex, optogenetics, ReaChR, somatosensory cortex, optogenetics, neuroscience
Research Division:	Biomedical and Clinical Sciences
Research Group:	Neurosciences
Research Field:	Central nervous system
Objective Division:	Expanding Knowledge
Objective Group:	Expanding knowledge
Objective Field:	Expanding knowledge in the biological sciences
UTAS Author:	Lin, JY (Dr John Lin)
ID Code:	99101
Year Published:	2015
Web of Science® Times Cited:	42
Deposited By:	Medicine
Deposited On:	2015-03-13
Last Modified:	2017-11-06
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