Increased levels of conditioned fear and avoidance behavior coincide with changes in phosphorylation of the protein kinase B (AKT) within the amygdala in a mouse model of extremes in trait anxiety
Abstract
Patients diagnosed for anxiety disorders often display faster acquisition and slower extinction of learned fear. To gain further insights into the mechanisms underlying these phenomenona, we studied conditioned fear in mice originating form a bi-directional selective breeding approach, which is based on elevated plus-maze behavior and results in CD1-derived high (HAB), normal (NAB), and low (LAB) anxiety-related behavior mice. HAB mice displayed pronounced cued-conditioned fear compared to NAB/CD1 and LAB mice that coincided with increased phosphorylation of the protein kinase B (AKT) in the basolateral amygdala 45 min after conditioning. No similar changes were observed after non-associative immediate shock presentations. Fear extinction of recent but not older fear memories was preserved. However, HAB mice were more prone to relapse of conditioned fear with the passage of time. HAB mice also displayed higher levels of contextual fear compared to NAB and LAB mice and exaggerated avoidance following step-down avoidance training. Interestingly, HAB mice showed lower and LAB mice higher levels of acoustic startle responses compared to NAB controls. The increase in arousal observed in LAB mice coincided with the general absence of...Continue Reading
References
Citations
Related Concepts
Related Feeds
Bipolar Disorder
Bipolar disorder is characterized by manic and/or depressive episodes and associated with uncommon shifts in mood, activity levels, and energy. Discover the latest research this illness here.
Attention Disorders
Attention is involved in all cognitive activities, and attention disorders are reported in patients with various neurological diseases. Here are the latest discoveries pertaining to attention disorders.
Amygdala and Midbrain Dopamine
The midbrain dopamine system is widely studied for its involvement in emotional and motivational behavior. Some of these neurons receive information from the amygdala and project throughout the cortex. When the circuit and transmission of dopamine is disrupted symptoms may present. Here is the latest research on the amygdala and midbrain dopamine.
Amygdala: Sensory Processes
Amygdalae, nuclei clusters located in the temporal lobe of the brain, play a role in memory, emotional responses, and decision-making. Here is the latest research on sensory processes in the amygdala.