A long-standing hypothesis termed "Hebbian plasticity" suggests that memories are formed through strengthening of synaptic connections between neurons with correlated activity. In contrast, other theories propose that coactivation of Hebbian and neuromodulatory processes produce the synaptic strengthening that underlies memory formation. Using optogenetics we directly tested whether Hebbian pla...

Aversive memories underlie many types of anxiety disorders. One area research to more effectively treat disorders has therefore been identifying pharmacological targets affect memory processes. Among these targets, the metabotropic glutamate 5 receptor (mGlu5) received attention due availability drugs utilize its role in learning and memory. In this review, we highlight preclinical studies exam...

The one-trial passive avoidance learning task is commonly used in avian research to explore anatomical, cellular and molecular parameters of learning and memory. Many factors are known to influence the effectiveness and/or duration of such learning events. Combinations of novel odours, such as pyrazine, and aposematic colours, such as brig ht yellow or red, have been shown to induce a long-last...

Learning and memory is not an attribute of higher animals. Even Drosophila larvae are able to form and recall an association of a given odor with an aversive or appetitive gustatory reinforcer. As the Drosophila larva has turned into a particularly simple model for studying odor processing, a detailed neuronal and functional map of the olfactory pathway is available up to the third order neuron...

The motivation to seek cocaine comes in part from a dysregulation of reward processing manifested in dysphoria, or affective withdrawal. Learning is a critical aspect of drug abuse; however, it remains unclear whether drug-associated cues can elicit the emotional withdrawal symptoms that promote cocaine use. Here we report that a cocaine-associated taste cue elicited a conditioned aversive stat...

Medial prefrontal cortex (mPFC) is essential for initial memory processing and expression but its involvement in persistent memory storage has seldom been studied. Using the hippocampus dependent inhibitory avoidance learning task and the hippocampus-independent conditioned taste aversion paradigm together with specific dopamine receptor agonists and antagonists we found that persistence but no...

Conditioning and extinction of fear have traditionally been viewed as two independent learning processes for encoding representations of contexts or cues (conditioned stimuli, CS), aversive events (unconditioned stimuli, US), and their relationship. Based on the analysis of protein kinase signaling patterns in neurons of the fear circuit, we propose that fear and extinction are best conceptuali...

Animals and humans learn to approach and acquire pleasant stimuli and to avoid or defend against aversive ones. However, both pleasant and aversive stimuli can elicit arousal and attention, and their salience or intensity increases when they occur by surprise. Thus, adaptive behavior may require that neural circuits compute both stimulus valence--or value--and intensity. To explore how these co...

Previous research has suggested that communication and especially promises increase cooperation in laboratory experiments. This has been taken as evidence for internal motivations such as guilt aversion or preference for promise keeping. The goal of this paper was to examine messages under a double-blind payoff procedure to test the alternative explanation that promise keeping is due to externa...