Pavlovian aversive conditioning is a fundamental form of learning helping organisms survive in their environment. Previous research has suggested that organisms are prepared to preferentially learn to fear stimuli that have posed threats to survival across evolution. Here, we examined whether enhanced Pavlovian aversive conditioning can occur to…

L-type voltage-gated calcium channels (LVGCCs) have been implicated in both the formation and the reduction of fear through Pavlovian fear conditioning and extinction. Despite the implication of LVGCCs in fear learning and extinction, studies of the individual LVGCC subtypes, Ca[subscript V]1.2 and Ca[subscript V] 1.3, using transgenic mice have…

Fear-relevant stimuli such as snakes and spiders are thought to capture attention due to evolutionary significance. Classical conditioning experiments indicate that these stimuli accelerate learning, while instructed extinction experiments suggest they may be less responsive to instructions. We manipulated stimulus type during instructed aversive…

Fear conditioning studies in rodents allow us to assess vulnerability factors which might underlie fear-based psychopathology such as post-traumatic stress disorder (PTSD). Despite PTSD being more prevalent in females than males, very few fear conditioning studies in rodents have tested females. Our study assessed fear conditioning and extinction…

Studies have shown that neonate rodents exhibit high ability to learn a preference for novel odors associated with thermo-tactile stimuli that mimics maternal care. Artificial odors paired with vigorous strokes in rat pups younger than 10 postnatal days (P), but not older, rapidly induce an orientation-approximation behavior toward the conditioned…

Honeybees are a standard model for the study of appetitive learning and memory. Yet, fewer attempts have been performed to characterize aversive learning and memory in this insect and uncover its molecular underpinnings. Here, we took advantage of the positive phototactic behavior of bees kept away from the hive in a dark environment and…

One experiment determined the relationship between renewed associative strength and attention. Following cue1-outcome pairings in Context A, cue1 was extinguished in Context B while cue2 was conditioned. On test cue2 was chosen as a predictor of the outcome in Context B. Both cues were chosen equally often as predictors in Context A. Consistent…

One experiment with rats explored whether an extinction-cue prevents the recovery of extinguished lever-pressing responses. Initially, rats were trained to perform one instrumental response (R1) for food in Context A, and a different instrumental response (R2) in Context B. Then, responses were extinguished each in the alternate context (R1 in…

This series of experiments used rats to compare counterconditioning and extinction of conditioned fear responses (freezing) with respect to the effects of a context shift. In each experiment, a stimulus was paired with shock in context A, extinguished or counterconditioned through pairings with sucrose in context B, and then tested for renewal…

The absence of a2* nicotinic acetylcholine receptors (nAChRs) in oriens lacunosum moleculare (OLM) GABAergic interneurons ablate the facilitation of nicotine-induced hippocampal CA1 long-term potentiation and impair memory. The current study delineated whether genetic mutations of a2* nAChRs ("Chrna2"[superscript L9'S/L9'S] and…

Clinical and preclinical studies that have examined the neurobiology of persistent fear memory in posttraumatic stress disorder (PTSD) have focused on the medial prefrontal cortex, hippocampus, and amygdala. Sensory systems, the periaqueductal gray (PAG), and midline thalamic nuclei have been implicated in fear and extinction memory, but whether…

Evaluative conditioning (EC) is a change in liking of neutral conditioned stimuli (CS) following pairings with positive or negative stimuli (unconditioned stimulus, US). A dissociation has been reported between US expectancy and CS evaluation in extinction learning: When CSs are presented alone subsequent to CS-US pairings, participants cease to…

Humans excel in categorization. Yet from a computational standpoint, learning a novel probabilistic classification task involves severe computational challenges. The present paper investigates one way to address these challenges: assuming class-conditional independence of features. This feature independence assumption simplifies the inference…

Anxiety disorders emerge early, and girls are significantly more likely to develop anxiety compared to boys. However, sex differences in fear during development are poorly understood. Therefore, we investigated juvenile male and female rats in the relapse behaviors following extinction of conditioned fear. In all experiments, 18-d-old rats first…

Zebrafish are a genetically tractable vertebrate that hold considerable promise for elucidating the molecular basis of behavior. Although numerous recent advances have been made in the ability to precisely manipulate the zebrafish genome, much less is known about many aspects of learning and memory in adult fish. Here, we describe the development…