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Cortical and hippocampal oscillations play a crucial role in the encoding, consolidation and retrieval of memory. Fast oscillations (sharp-wave ripples) have been shown to be necessary for the consolidation of memory. During consolidation, information is transferred from the hippocampus to the neocortex. One of the structures at the interface between hippocampus and neocortex is the subiculum. It is therefore well suited to mediate transfer and distribution of information from the hippocampus to other areas. By juxtacellular and whole-cell recordings in awake mice we show that in the subiculum a subset of pyramidal cells is activated whereas another subset is inhibited during fast oscillations. We demonstrate that these functionally different subgroups are predetermined by their cell type. Bursting cells are selectively employed to transmit information during fast oscillations, whereas regular firing cells are silenced. With multiple recordings in vitro we show that the cell-type specific differences extend into the local network architecture. This is reflected in an asymmetric wiring scheme where bursting cells and regular firing cells are recurrently connected among themselves but connections between cell types exclusively exist from regular to bursting cells. The total excitation onto bursting cells within the local network is therefore larger than onto regular-firing cells. We conclude that information transmitted during sharp-wave ripples is preferentially routed to target regions of burst firing cells.

Since the 19th century neuroscientists have pondered the question of how the brain maintains a spatially accurate visual signal despite a constantly moving eye. Hering said to measure where the eye is in the orbit. Helmholtz said to adjust the visual representation by the dimensions of an upcoming movement. Both were right. Visual responses in the lateral intraparietal area (LIP) are modulated by eye position, and target position in supraretinnal coordinates can be calculated from this modulation. The eye position signals for this modulation come from the representation of eye position in somatosensory cortex. This eye position signal is, however, too slow to be accurate within 150 ms after a saccade. However, immediately before a saccade neurons in LIP respond to stimuli that will be brought into their receptive fields by an impending saccade. The signal that remaps the receptive field arises from a corollary discharge of the motor command, and a computational model shows that this remapping can be effected by a wave of activity in the cortex that propagates from the cell driven by the stimulus before the saccade to the cell in whose receptive field the stimulus will lie after the saccade. Thus spatial accuracy is effected by two systems, a relatively inaccurate, fast system using corollary discharge, and a slower proprioceptive system that more accurately measure the position of the eye in the orbit.