Journal Article

Hippocampal long-term depression is required for the consolidation of spatial memory

Ge, Yuan, Wang, Yu Tian, Howland, John G., Dong, Zhifang, Wong, Tak Pan, Bagot, Rosemary C., Phillips, Anthony G.

2010

Overview

Although NMDA receptor (NMDAR)-dependent long-term potentiation (LTP) and long-term depression (LTD) of glutamatergic transmission are candidate mechanisms for long-term spatial memory, the precise contributions of LTP and LTD remain poorly understood. Here, we report that LTP and LTD in the hippocampal CA1 region of freely moving adult rats were prevented by NMDAR 2A (GluN2A) and 2B subunit (GluN2B) preferential antagonists, respectively. These results strongly suggest that NMDAR subtype preferential antagonists are appropriate tools to probe the roles of LTP and LTD in spatial memory. Using a Morris water maze task, the LTP-blocking GluN2A antagonist had no significant effect on any aspect of performance, whereas the LTD-blocking GluN2B antagonist impaired spatial memory consolidation. Moreover, similar spatial memory deficits were induced by inhibiting the expression of LTD with intrahippocampal infusion of a short peptide that specifically interferes with AMPA receptor endocytosis. Taken together, our findings support a functional requirement of hippocampal CA1 LTD in the consolidation of long-term spatial memory.

• Publisher: National Academy of Sciences,National Acad Sciences
• Subject: a-Amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors / adults / alpha -Amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors / Amino acids / Animal memory / Animals / Antagonists / Biological Sciences / Brain / CA1 Region, Hippocampal - physiology / Endocytosis / Excitatory Amino Acid Antagonists - pharmacology / Excitatory Postsynaptic Potentials - drug effects / Gene expression / Glutamatergic transmission / Glutamic acid receptors / Glutamic acid receptors (ionotropic) / Hippocampus / Hippocampus - physiology / Histograms / Injections / Long term depression / Long term potentiation / Long-Term Potentiation - drug effects / Long-Term Potentiation - physiology / Long-Term Synaptic Depression - drug effects / Long-Term Synaptic Depression - physiology / Male / Maze Learning - drug effects / Maze Learning - physiology / Memory / Memory - drug effects / Memory - physiology / Memory recall / N methyl D aspartate receptors / N-Methyl-D-aspartic acid receptors / Peptides / Phenols - pharmacology / Piperazines - pharmacology / Piperidines - pharmacology / Post hoc / Probes / Protein Subunits / Quinoxalines - pharmacology / Rats / Rats, Sprague-Dawley / Receptors, N-Methyl-D-Aspartate - antagonists & inhibitors / Receptors, N-Methyl-D-Aspartate - chemistry / Receptors, N-Methyl-D-Aspartate - classification / Rodents / Spatial Behavior - drug effects / Spatial Behavior - physiology / spatial memory / Training