TY - JOUR T1 - How activity dependent feedback inhibition may maintain head direction signals in mouse presubiculum JF - bioRxiv DO - 10.1101/106005 SP - 106005 AU - Jean Simonnet AU - Mérie Nassar AU - Federico Stella AU - Ivan Cohen AU - Bertrand Mathon AU - Charlotte N. Boccara AU - Richard Miles AU - Desdemona Fricker Y1 - 2017/01/01 UR - http://biorxiv.org/content/early/2017/02/04/106005.abstract N2 - Orientation in space is represented in specialized brain circuits. Persistent head direction signals are transmitted from anterior thalamus to the presubiculum, but the identity of the presubicular target neurons, their connectivity and function in local microcircuits are unknown. Here we examine how thalamic afferents recruit presubicular principal neurons and Martinotti interneurons and the ensuing synaptic interactions between these cells. Pyramidal neuron activation of Martinotti cells in superficial layers is strongly facilitating such that high frequency head directional stimulation efficiently unmutes synaptic excitation. Martinotti cell feedback plays a dual role: precisely timed spikes may not inhibit the firing of in-tune head direction cells, while exerting lateral inhibition. Autonomous attractor dynamics emerge from a modeled network implementing wiring motifs and timing sensitive synaptic interactions in the pyramidal - Martinotti cell feedback loop. This inhibitory microcircuit is therefore tuned to refine and maintain head direction information in the presubiculum. ER -