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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.

Rates of food insecurity are high among adults with serious mental illness (SMI); this population also engages in less physical activity than the general population. However, the relationship between food insecurity and physical activity in this group has not been explored. We examined food insecurity prevalence and its association with physical activity in 314 adults with SMI living in supportive housing in New York City and Philadelphia and enrolled in an institutional review board-approved randomized controlled trial of a Peer Group Lifestyle Balance (PGLB) program. We analyzed 2014 baseline survey data, including demographic data and self-reported food security, and four self-reported physical activity outcomes: any physical activity per week (yes/no) and 2) total, 3) moderate, or 4) vigorous physical activity minutes per week. A logistic regression model examined food security as a predictor of any physical activity; zero-inflated negative binomial regression models were used for the other three physical activity outcomes; demographic and clinical predictors were assessed for inclusion in models. Over half of participants (51.7%) reported low or very low levels of food security. Relationships between food insecurity and three physical activity measures (any physical activity, total weekly minutes, and moderate weekly minutes) were non-significant; those with lower food security were more likely to engage in vigorous physical activity. The high food insecurity prevalence highlights the importance of measuring and addressing food security in populations experiencing SMI; measuring physical activity is also important for tailored lifestyle recommendations. Future studies should examine longitudinal changes in food security and physical activity.