TY - JOUR T1 - Distinct organization of two cortico-cortical feedback pathways JF - bioRxiv DO - 10.1101/2020.02.27.968792 SP - 2020.02.27.968792 AU - Shan Shen AU - Xiaolong Jiang AU - Federico Scala AU - Jiakun Fu AU - Paul Fahey AU - Dimitry Kobak AU - Zhenghuan Tan AU - Jacob Reimer AU - Fabian Sinz AU - Andreas S. Tolias Y1 - 2020/01/01 UR - http://biorxiv.org/content/early/2020/02/28/2020.02.27.968792.abstract N2 - Neocortical feedback is critical for processes like attention, prediction, and learning. A mechanistic understanding of its function requires deciphering its cell-type wiring logic. Recent studies revealed a disinhibitory circuit between motor and sensory areas in mice, where feedback preferentially targets vasointestinal peptide-expressing interneurons, in addition to pyramidal cells. It is unknown whether this circuit motif is a general cortico-cortical feedback organizing principle. Combining multiple simultaneous whole-cell recordings with optogenetics we found that in contrast to this wiring rule, feedback between the hierarchically organized visual areas (lateral-medial to V1) preferentially activated somatostatin-expressing interneurons. Functionally, both feedback circuits temporally sharpened feed-forward excitation by eliciting a transient increase followed by a prolonged decrease in pyramidal firing rate under sustained feed-forward input. However, under feed-forward transient input, the motor-sensory feedback facilitated pyramidal cell bursting while visual feedback increased spike time precision. Our findings argue for multiple feedback motifs implementing different dynamic non-linear operations. ER -