iScience (Nov 2023)

Distinct effects of AMPAR subunit depletion on spatial memory

  • Ahmed Eltokhi,
  • Ilaria Bertocchi,
  • Andrei Rozov,
  • Vidar Jensen,
  • Thilo Borchardt,
  • Amy Taylor,
  • Catia C. Proenca,
  • John Nick P. Rawlins,
  • David M. Bannerman,
  • Rolf Sprengel

Journal volume & issue
Vol. 26, no. 11
p. 108116

Abstract

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Summary: Pharmacological studies established a role for AMPARs in the mammalian forebrain in spatial memory performance. Here we generated global GluA1/3 double knockout mice (Gria1/3−/−) and conditional knockouts lacking GluA1 and GluA3 AMPAR subunits specifically from principal cells across the forebrain (Gria1/3ΔFb). In both models, loss of GluA1 and GluA3 resulted in reduced hippocampal GluA2 and increased levels of the NMDAR subunit GluN2A. Electrically-evoked AMPAR-mediated EPSPs were greatly diminished, and there was an absence of tetanus-induced LTP. Gria1/3−/− mice showed premature mortality. Gria1/3ΔFb mice were viable, and their memory performance could be analyzed. In the Morris water maze (MWM), Gria1/3ΔFb mice showed profound long-term memory deficits, in marked contrast to the normal MWM learning previously seen in single Gria1−/− and Gria3−/− knockout mice. Our results suggest a redundancy of function within the pool of available ionotropic glutamate receptors for long-term spatial memory performance.

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