Psychology

A schematic model of the neural circuits involved in the afferent input of fear- and anxiety-inducing stimuli and the processing of the stimuli. The amygdala plays a pivotal role in the assessment of danger and the response. The LC is a critical component in both afferent and efferent systems, mainly through NE release. The amygdala receives input from PAG, LC, thalamus, hippocampus, association cortices, entorhinal cortex, and visceral pathways. Input from mPFC is involved in determining the significance of fear-producing sensory events, the choice and implementation and the type of behavior, and the extinction of conditioned fear responses. States of stress and fear result in a rapid increase in firing of neurons in the LC, with release of NE transmitter in different target sites in the brain. This results in an increase in attention and vigilance, as well as enhancement of memory recall, which can be life saving in threatenting situations. Patients with anxiety disorder, however, develop long-term alterations in the function of this system. The fear response is dependent on previous experience, sensitization, fear conditioning, and extinction of previous fear responses.

Ix. A working model for the neural circuitry of anxiety disorders. (2002). In V. S. Ramachandran, Encyclopedia of the human brain. Elsevier Science & Technology. Credo Reference: https://login.proxy013.nclive.org/login?url=https://search.credoreference.com/content/entry/esthumanbrain/ix_a_working_model_for_the_neural_circuitry_of_anxiety_disorders/0?institutionId=4696