TY - JOUR T1 - The Postsubiculum and Spatial Learning: The Role of Postsubicular Synaptic Activity and Synaptic Plasticity in Hippocampal Place Cell, Object, and Object-Location Memory JF - The Journal of Neuroscience JO - J. Neurosci. SP - 6928 LP - 6943 DO - 10.1523/JNEUROSCI.5476-12.2013 VL - 33 IS - 16 AU - David Bett AU - Cassie H. Stevenson AU - Kate L. Shires AU - Michael T. Smith AU - Stephen J. Martin AU - Paul A. Dudchenko AU - Emma R. Wood Y1 - 2013/04/17 UR - http://www.jneurosci.org/content/33/16/6928.abstract N2 - Visual landmarks exert stimulus control over spatial behavior and the spatially tuned firing of place, head-direction, and grid cells in the rodent. However, the neural site of convergence for representations of landmarks and representations of space has yet to be identified. A potential site of plasticity underlying associations with landmarks is the postsubiculum. To test this, we blocked glutamatergic transmission in the rat postsubiculum with CNQX, or NMDA receptor-dependent plasticity with d-AP5. These infusions were sufficient to block evoked potentials from the lateral dorsal thalamus and long-term depression following tetanization of this input to the postsubiculum, respectively. In a second experiment, CNQX disrupted the stability of rat hippocampal place cell fields in a familiar environment. In a novel environment, blockade of plasticity with d-AP5 in the postsubiculum did not block the formation of a stable place field map following a 6 h delay. In a final behavioral experiment, postsubicular infusions of both compounds blocked object-location memory in the rat, but did not affect object recognition memory. These results suggest that the postsubiculum is necessary for the recognition of familiar environments, and that NMDA receptor-dependent plasticity in the postsubiculum is required for the formation of new object–place associations that support recognition memory. However, plasticity in the postsubiculum is not necessary for the formation of new spatial maps. ER -