The hippocampus and amygdala are thought to be functionally distinct components of different learning and memory systems. This functional dissociation has been particularly apparent in pavlovian fear conditioning, where the integrity of the hippocampus is necessary for contextual conditioning, and of the amygdala for discrete cue conditioning. Their respective roles in appetitive conditioning, ...

Introduction: The influence of ascorbic acid on the nicotine-induced conditioned place preference (CPP) and behavioral sensitization was investigated in the present study. Methods: In a pilot study, place conditioning and locomotor activity were investigated after nicotine (0.25, 0.5, 0.75, 1, 1.5 and 2 mg/kg) or ascorbic acid (1, 10, 100 and 1000 mg/kg) administration. Different doses of a...

The activity of dopamine (DA)-containing neurons in the ventral tegmental area (VTA) is a key mechanism in mesolimbic reward processing that has modulatory effects on different diencephalic structures like hippocampus (HIP), and receives inhibitory feedback and excitatory feed forward control. In addition, within the hippocampus, DA receptors are mostly located in the dorsal part (CA1) and dopa...

Reactivation of memories may render them labile and subject to disruption by amnestic drugs thus reducing their impact on future behavior, but whether it is possible with well-established memories is not known. Here we examined the effect of two amnestic agents on reconsolidation of a conditioned place preference (CPP) for morphine when memory strength and memory age were varied. In a three-com...

BACKGROUND A main challenge in the therapy of drug dependent individuals is to help them reactivate interest in non-drug-associated activities. Among these activities, social interaction is doubly important because treatment adherence itself depends on it. We previously developed a rat experimental model based on the conditioned place preference (CPP) paradigm in which only four 15-min episodes...

The extinction of learned fear is a hippocampus-dependent process thought to embody new learning rather than erasure of the original fear memory, although it is unknown how these competing contextual memories are represented in the hippocampus. We previously demonstrated that contextual fear conditioning results in hippocampal place cell remapping and long-term stabilization of novel representa...

Animals return to rewarded locations. An example of this is conditioned place preference (CPP), which is widely used in studies of drug reward. Although CPP is expressed as increased time spent in a previously rewarded location, the behavioral strategy underlying this change is unknown. We continuously monitored rats (n = 22) in a three-room in-line configuration, before and after morphine cond...

When rats and mice are free to explore a familiar environment they spend more time in a previously rewarded location. This conditioned place preference (CPP) results from an increased probability of initiating transitions from an unrewarded location to one previously paired with reward. We recorded nucleus accumbens (NAc) neurons while rats explored a three-room in-line apparatus. Before place ...

Lesions of the amygdala impair acquisition of a food conditioned place preference (CPP) task. In contrast, lesions of the fornix facilitate acquisition on this task, showing that an intact hippocampal system can interfere with learning an amygdala-dependent task. Our recent findings indicate that acetylcholine (ACh) release in the hippocampus increases while rats perform a hippocampus-dependent...