%A Lim,Diana %A Mohajerani,Majid %A LeDue,Jeffrey %A Boyd,Jamie %A Chen,Shangbin %A Murphy,Timothy %D 2012 %J Frontiers in Neural Circuits %C %F %G English %K channelrhodopsin,connectivity,cortical mapping,in vivo imaging,Network analysis,optogenetics,reciprocal connections,voltage sensistive dye %Q %R 10.3389/fncir.2012.00011 %W %L %M %P %7 %8 2012-March-15 %9 Original Research %+ Dr Timothy Murphy,University of British Columbia,Department of Psychiatry,2255 Wesbrook Mall,Vancouver,V6T 1Z3,Vancouver,Canada,thmurphy@mail.ubc.ca %+ Dr Timothy Murphy,University of British Columbia,Brain Research Centre,2211 Wesbrook Mall,Vancouver, BC,V6T 2B5,British Columbia,Canada,thmurphy@mail.ubc.ca %# %! in vivo optogenetic intracortical mapping %* %< %T In vivo Large-Scale Cortical Mapping Using Channelrhodopsin-2 Stimulation in Transgenic Mice Reveals Asymmetric and Reciprocal Relationships between Cortical Areas %U https://www.frontiersin.org/articles/10.3389/fncir.2012.00011 %V 6 %0 JOURNAL ARTICLE %@ 1662-5110 %X We have mapped intracortical activity in vivo independent of sensory input using arbitrary point channelrhodopsin-2 (ChR2) stimulation and regional voltage sensitive dye imaging in B6.Cg-Tg (Thy1-COP4/EYFP)18Gfng/J transgenic mice. Photostimulation of subsets of deep layer pyramidal neurons within forelimb, barrel, or visual primary sensory cortex led to downstream cortical maps that were dependent on synaptic transmission and were similar to peripheral sensory stimulation. ChR2-evoked maps confirmed homotopic connections between hemispheres and intracortical sensory and motor cortex connections. This ability of optogentically activated subpopulations of neurons to drive appropriate downstream maps suggests that mechanisms exist to allow prototypical cortical maps to self-assemble from the stimulation of neuronal subsets. Using this principle of map self-assembly, we employed ChR2 point stimulation to map connections between cortical areas that are not selectively activated by peripheral sensory stimulation or behavior. Representing the functional cortical regions as network nodes, we identified asymmetrical connection weights in individual nodes and identified the parietal association area as a network hub. Furthermore, we found that the strength of reciprocal intracortical connections between primary and secondary sensory areas are unequal, with connections from primary to secondary sensory areas being stronger than the reciprocal.