The amygdala as a target for behavior surgery

Abstract

The amygdala was a popular target during the era of psychosurgery, specifically for the treatment of intractable aggression. This mesiotemporal structure was thought to primarily mediate fear and anger. However, recent evidence suggests that the amygdala is part of a complex network that mediates the formation of a larger repertoire of positive and negative emotions. Dysfunctions within the network or the amygdala itself can lead to various mental illnesses. In those cases, deep brain stimulation (DBS) applied focally may treat the symptoms. This review presents data supporting the potential therapeutic role of DBS of the amygdala in the treatment of anxiety disorders, addiction, and mood disorders. The success of DBS for psychiatric conditions will likely depend on our ability to precisely determine the optimal target for a specific case.

Keywords: Addiction; amygdala; deep brain stimulation; depression; post-traumatic stress disorder.

Figure 1

The amygdala and its network. This figure shows selected afferents and efferents of the amygdala. Functional groups are color coded. The amygdala screens stimuli received from high-order sensory cortices (orange pathway). The response of the amygdala to the incoming stimulus is determined by the activity of several modulation pathways. These pathways include a context- and memory-based modulation (green pathway), a top-down modulation (red pathway), and a reward-based modulation (blue pathway). BLn: Basolateral nucleus, CEA: Central nucleus of the amygdala, DM Vagus: Dorsal motor nucleus of the Vagus, Lat. Habenual: Lateral habenula, mPFC: medial prefrontal cortex, Nacc: Nucleus accumbens, PAG: Periacqueductal gray area, Rmtg: Rostromedial tegmental nucleus, VTA: Ventral tegmental area