BRIEF EXPOSURE TO A NOVEL CONTEXT ENHANCES CONSOLIDATION OF OBJECT MEMORY IN C57BL/6J MICE

Previous research revealed that episodic memories are more likely to be consolidated if something novel occurs in relative temporal proximity to the original learned event (Dunsmoor, Murty, Davachi, & Phelps, 2015). Further, research conducted with rodents has revealed that novel contextual exposure following encoding of a spatial memory in a food-motivated task results in enhanced consolidation of that spatial memory (Takeuchi, Duszkiewics, Sonneborn et al., 2016). The present study sought to examine the influence of novel context exposure on non-spatial object memory in adult female and male C57BL/6J mice when novel context exposure follows encoding of object memory under two memory strength training protocols. Results revealed that regardless of memory strength or gender, subjects exposed to a novel context following encoding of object memory exhibited greater exploration of the novel object when assessed 23.5 h later. Thus, novel context exposure significantly enhanced the consolidation of recently encoded object memory. As novel context exposure has been shown to increase dopamine release in the hippocampus, these results are consistent with the theory of synaptic tag and capture, whereby activated dopaminergic afferents enhance the on-going consolidation of non-spatial object memory. Future studies will entail parsing potential neurotransmitter modulatory afferents via pharmacological antagonists.