Why do we need it? The amygdala is involved in fear, anxiety and aggression. Monkeys without an amygdala are not appropriately afraid of humans or of the boss monkey of their troop. Rats without an amygdala might play with their native predators, such as cats or snakes. A person with a dysfunctional amygdala finds everyone trustworthy, and can’t sense when someone else is afraid. It’s also now ...

Recent evidence indicates that networks including the amygdala and prefrontal cortex provide a key interface between affect and cognition. Converging evidence from rodents, humans, and non-human primates indicates that interconnections between the basolateral complex of the amygdala and the orbitofrontal cortex are crucial to the formation and use of expectancies of reinforcers in the guidance ...

Fear memories can be attenuated by reactivation followed by disrupted reconsolidation. Using functional magnetic resonance imaging we recently showed that reactivation and reconsolidation of a conditioned fear memory trace in the basolateral amygdala predicts subsequent fear expression over two days, while reactivation followed by disrupted reconsolidation abolishes the memory trace and suppres...

Objective(s): Post-traumatic stress disorder (PTSD), one of the most devastating kinds of anxiety disorders, is the consequence of a traumatic event followed by intense fear. In rats with contextual fear conditioning (CFC), a model of PTSD caused by CFC (electrical foot shock chamber), deep brain stimulation (DBS) alleviates CFC abnormalities.Materials and Methods: Forty Male Wistar rats (220–2...

Studies of amygdala functioning have occupied a significant place in the history of understanding how the brain controls behavior and cognition. Early work on the amygdala placed this small structure as a key component in the regulation of emotion and affective behavior. Over time, our understanding of its role in brain processes has expanded, as we have uncovered amygdala influences on memory,...

Increasing evidence suggests that substance P (SP) and its preferred receptor, namely the neurokinin 1 receptor (NK1-R), play an important role in the modulation of stress-related, affective and/or anxious behaviours. Both SP and NK1-R are expressed in brain regions critically involved in stress, fear and affective responses such as the amygdala, hippocampus and frontal cortex. In this study we...

There is strong evidence that two cerebral hemispheres are differentially involved in emotional memory and that amygdala is a key subcortical structure for emotional experience. The present research investigated the possible involvement of lateralization of basolateral amygdala (BLA) and central amygdala (CEA) in place avoidance memory. For this purpose, male Long-Evans rats (280-320 g) were im...

The amygdala, part of the limbic system, is a small collection of neurons located in the ventral temporal lobe, and can be divided into two morphologically and functionally distinct nuclei - the corticomedial, a phylogenetically old group, and the basolateral, a phylogenetically more recent group. Both divisions of the amygdala have extensive interconnections with the hypothalamus, the corticom...

Maladaptive responses to pain-related distress, such as pain catastrophizing, amplify the impairments associated with chronic pain. Many of these aspects of chronic pain are similar to affective distress in clinical anxiety disorders. In light of the role of the amygdala in pain and affective distress, disruption of amygdalar functional connectivity in anxiety states, and its implication in the...

Anxiety is integrated in the amygdaloid nuclei and involves the interplay of the amygdala and various other areas of the brain. Neuropeptides play a critical role in regulating this process. Neuropeptide Y (NPY), a 36 aa peptide, is highly expressed in the amygdala. It exerts potent anxiolytic effects through cognate postsynaptic Y1 receptors, but augments anxiety through presynaptic Y2 recepto...