Channelrhodopsin-Assisted Patching: In Vivo Recording of Genetically and Morphologically Identified Neurons throughout the Brain

• Published in: Cell reports (Cambridge) Vol. 9; no. 6; pp. 2304 - 2316
• Main Authors: Muñoz, William, Tremblay, Robin, Rudy, Bernardo
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 24-12-2014; Elsevier
• Subjects: Animals; Brain - cytology; Brain - physiology; Channelrhodopsins; GABAergic Neurons - metabolism; GABAergic Neurons - physiology; Mice; Optogenetics - methods; Patch-Clamp Techniques - methods
• ISSN: 2211-1247; 2211-1247
• DOI: 10.1016/j.celrep.2014.11.042

Brain networks contain a large diversity of functionally distinct neuronal elements, each with unique properties, enabling computational capacities and supporting brain functions. Understanding their functional implications for behavior requires the precise identification of the cell types of a network and in vivo monitoring of their activity profiles. Here, we developed a channelrhodopsin-assisted patching method allowing the efficient in vivo targeted recording of neurons identified by their molecular, electrophysiological, and morphological features. The method has a high yield, does not require visual guidance, and thus can be applied at any depth in the brain. This approach overcomes limitations of present technologies. We validate this strategy with in vivo recordings of identified subtypes of GABAergic and glutamatergic neurons in deep cortical layers, subcortical cholinergic neurons, and neurons in the thalamic reticular nucleus in anesthetized and awake mice. We propose this method as an important complement to existing technologies to relate specific cell-type activity to brain circuitry, function, and behavior.
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•High-yield in vivo targeting of identified neurons regardless of recording depth•Reliable identification of light-activated ChR2-expressing neurons in vivo•Electrophysiological and morphological dissection of deep cortical interneurons•Targeted intracellular recording independent of visual guidance
Combining in vivo optogenetics with juxtacellular recording and labeling technologies, Muñoz et al. introduce a new method facilitating the identification and activity monitoring of cell types in anesthetized and awake preparations. This method promises to foster our understanding of the particular function of the distinct cellular elements composing complex brain networks.