Analysis of Transsynaptic Attentional Neuronal Circuits with Octuple Patch-Clamp Recordings

Deciphering interneuronal circuitry is essential to understanding brain functions yet remains a daunting task in neurobiology. To facilitate the dissection of complex cortical neuronal circuits, a process requiring analysis of synaptic interconnections and identification of cell types of interconnected neurons, we have developed a simultaneous quadruple-octuple whole-cell recordings technique that allows physiological analysis of synaptic interconnection among up to eight neurons and anatomical identification of the majority of recorded neurons. Using this method, we have recently revealed two transsynaptic disinhibitory and inhibitory circuits connecting layer 1–3 interneurons with pyramidal neurons in both supragranular and infragranular cortical layers of the rat neocortex. Here, we outline the technique that permits decoding the complex cortical interneuronal circuits involved in controlling salience detection.