The Role of the Basolateral Nuclear Complex & Central Nucleus of the Amygdala in Fear-Conditioned Responses to External Stimuli and Anxiety Responses

This thesis reviews the role of the amygdala, particularly the basolateral nuclear complex (BLA) and central nucleus (CeA), in fear-conditioned responses and generalized anxiety disorder (GAD). By investigating the neurological and physiological mechanisms that influence the amygdala’s fear and anxiety responses, further connections can be made between this region and other notable brain regions, like the prefrontal cortex (PFC). We review both human and rodent models to explore the overlap between the two and explore various therapeutic interventions that regulate amygdalar activity and therefore mitigate anxiety symptoms. Key research into the patient SM, who lacks fear responses due to bilateral amygdala lesions have shown the influence of the amygdala in fear responses and the dangers that can arise due to lesions in this region. This review also highlights the emerging pharmacological and non-invasive techniques, such as propranolol and transcranial magnetic stimulation (TMS) that might enhance PFC function and thus reduce amygdala hyperactivity. These studies provide various avenues for anxiety treatment, thereby offering a holistic and effective means of treatment for a number of individuals with anxiety disorders. This thesis concludes that integrating advancements in neurobiology, biomedical technology, and non-invasive techniques could result in more holistic treatments for GAD, thereby enhancing the quality of life for individuals with anxiety disorders.