Multiple lines of evidence suggest that glucocorticoid hormones enhance memory consolidation of fearful events. However, most of these studies involve male individuals. Since anxiety, fear, and fear-associated disorders present differently in male and female subjects we investigated in mice whether male and female mice perform differently in a…

Recent studies have shown that exposure to a novel environment may stabilize the persistence of weak memories, a phenomenon often attributed to a process referred to as "behavioral tagging." While this phenomenon has been repeatedly demonstrated in adult animals, no studies to date have examined whether it occurs in infant animals, which…

Declarative memory performance is superior for items that were encoded in temporal proximity to reward delivery or expectancy. How reward-predicting contexts affect subsequent declarative memory formation in those contexts are, however, unknown. Using an ecological experimental setup in the form of a naturalistic driving simulator task, we…

Conditioned fear memories that are context-specific shortly after conditioning generalize over time. We exposed rats to a context reminder 30 d after conditioning, which served to reinstate context-specificity, and investigated how this reminder alters retrieval-induced activity in the hippocampus and anterior cingulate cortex (aCC) relative to a…

The nucleus reuniens of the thalamus (RE) is a key component of an extensive network of hippocampal and cortical structures and is a fundamental substrate for cognition. A common misconception is that RE is a simple relay structure. Instead, a better conceptualization is that RE is a critical component of a canonical higher-order…

microRNAs (miRNAs) have emerged as potent regulators of learning, recent memory, and extinction. However, our understanding of miRNAs directly involved in regulating complex psychiatric conditions perpetuated by aberrant memory, such as in posttraumatic stress disorder (PTSD), remains limited. To begin to address the role of miRNAs in persistent…

Spatial memory impairment is well documented in old age; however, less is known about spatial memory during middle age. We examined the performance of healthy young, middle-aged, and older adults on a spatial memory task with varying levels of spatial similarity (distance). On low similarity trials, young adults significantly outperformed…

To test the hypothesis that thalamic midline nuclei play a transient role in memory consolidation, we reanalyzed a prospective functional MRI study, contrasting recent and progressively more remote memory retrieval. We revealed a transient thalamic connectivity increase with the hippocampus, the medial prefrontal cortex (mPFC), and a…

Avoiding unfavorable situations is a vital skill and a constant task for any animal. Situations can be unfavorable because they feature something that the animal wants to escape from, or because they do not feature something that it seeks to obtain. We investigate whether the microbehavioral mechanisms by which these two classes of aversion come…

Sleep supports memory consolidation as shown in mammals and invertebrates such as bees and "Drosophila." Here, we show that sleep's memory function is preserved in "Aplysia californica" with an even simpler nervous system. Animals performed on an inhibitory conditioning task ("learning that a food is inedible") three…

The context preexposure facilitation effect (CPFE) is a contextual fear conditioning paradigm in which learning about the context, acquiring the context-shock association, and retrieving/expressing contextual fear are temporally dissociated into three distinct phases. In contrast, learning about the context and the context-shock association…

The creation of auditory threat Pavlovian memory requires an initial learning stage in which a neutral conditioned stimulus (CS), such as a tone, is paired with an aversive one (US), such as a shock. In this phase, the CS acquires the capacity of predicting the occurrence of the US and therefore elicits conditioned defense responses.…

The insular cortex (IC) is required for conditioned taste aversion (CTA) retrieval. However, it remains unknown which cortical neurotransmitters levels are modified upon CTA retrieval. Using in vivo microdialysis, we observed that there were clear elevations in extracellular glutamate, norepinephrine, and dopamine in and around the center of the…

We characterized the transcriptional response accompanying maintenance of long-term sensitization (LTS) memory in the pleural ganglia of "Aplysia californica" using microarray (N = 8) and qPCR (N = 11 additional samples). We found that 24 h after memory induction there is strong regulation of 1198 transcripts (748 up and 450 down) in a…

According to dual-process theory, recognition memory performance draws upon two processes, familiarity and recollection. The relative contribution to recognition memory are commonly distinguished in humans by analyzing receiver-operating-characteristics (ROC) curves; analogous methods are more complex and very rare in animals but fast familiarity…