Determinants of object‐in‐context and object‐place‐context recognition in the developing rat

Abstract

Since the seminal report on novel object recognition in the rat (Ennaceur & Delacour, 1988), novelty recognition paradigms have become increasingly prevalent in learning and memory research. Novelty recognition tasks do not require extensive training or complex behaviors, and thus are especially suitable for studying the ontogeny of various forms of memory (e.g., object, spatial, and contextual memory). However, relatively little is known about the determinants of recognition memory during development. The present study extends our recent research on the development of recognition memory by further characterizing the ontogeny of contextual recognition (Ramsaran, Westbrook, & Stanton, 2016). We report that long-term retention of object-in-context (OiC) memory emerges during early development in the rat (Experiment 1), and that performance of object-place-context (OPC), a spatial variant of the OiC task, also displays protracted development until early adolescence (Experiment 2). In addition, we examined the role of NMDA receptors (NMDARs) in contextual recognition and found that OiC memory is not dependent on NMDAR-mediated plasticity whereas performance of spatial task variants including the distal cue OiC (Ramsaran et al., 2016) and OPC tasks are NMDAR-dependent (Experiments 3 and 4). The ontogeny of contextual recognition is influenced by memory retention and spatial processing demands, which may also determine the neurobiological mechanisms supporting task performance.

Maternal and offspring methylenetetrahydrofolate‐reductase genotypes interact in a mouse model to induce autism spectrum disorder‐like behavior

“…Recognition memory depends on mature mPFC‐hippocampus and hippocampal‐entorhinal cortex circuitry . The maturation of this circuitry, which in healthy mice appears to parallel the maturation of mPFC glutamatergic innervation (around the age of P30 in rodents), was previously exemplified by late onset of the ability to perform a task . In males, both the maternal and offspring Mthfr genotypes contributed to memory impairment.…”

Mouse knockout of guanylyl cyclase C: Recognition memory deficits in the absence of activity changes

“…NOR is mediated in part by the hippocampus. Most evidence supports a role for N‐methyl‐D‐aspartate ‐ receptor (NMDA‐R) in mediating novelty recognition; however, there are conflicting data . We did not assess NMDA‐R levels here.…”

NMDA receptors and the ontogeny of post‐shock and retention freezing during contextual fear conditioning

“…It has been previously shown that NMDARs are involved in learning tasks during the pre‐weanling period of development (Highfield, Nixon, & Amsel, ; Langton, Kim, Nicholas, & Richardson, ; Lincoln, Coopersmith, Harris, Cotman, & Leon, ). The role of NMDARs in learning and memory has been previously examined by our lab in developmental studies of the CPFE (Heroux et al, ; Schiffino et al, ) and various hippocampal‐dependent object recognition tasks (Jablonski, Schreiber, Westbrook, Brennan, & Stanton, ; Ramsaran, Sanders, & Stanton, ); as well as T‐maze working memory and reversal tasks (Chadman, Watson, & Stanton, ; Watson, Herbert, & Stanton, ; Watson & Stanton, ). In the CPFE, systemic NMDAR antagonism during context preexposure or training phases disrupts retention test freezing in PD24 and PD31 rats (Burman, Murawski, Schiffino, Rosen, & Stanton, ; Heroux et al, ).…”