Amygdala Pathways
The amygdala twins have also many connections with the hypothalamus, the septum, the reticular formation of the brainstem, and the hippocampus. Since the hippocampus is involved in storing and retrieving explicit memories, its connections to the amygdalas are the origin of strong emotions triggered by particular memories.
The primary and automatic bodily responses involved in emotions such as fear are controlled mainly by the outputs of the amygdala to the nuclei of the sympathetic nervous system in the brainstem and to the hypothalamus, which itself controls the hormonal secretions of the pituitary gland.
The amygdala’s actions show us what is necessary to experience an emotion such as fear. The connections from the amygdala to the cortex can influence perception and memory of dangerous situations.
The amygdala also influences the cortex indirectly, through its connections within the brainstem. Parts of the brainstem can trigger a cascade of physiological reactions associated with fear that is then sent as feedback to the brain.
The connections from the prefrontal cortex to the amygdala involve secondary emotions. They give us a certain conscious control over those emotions, as anxiety.
However, the cortex can create anxiety by allowing us to imagine the failure of a given scenario or even the presence of dangers that do not actually exist.
Most of the neural pathways that enter the amygdala twins are paired with other pathways that exit it. The gratifying or aversive nature of a stimulus is associated by connections of this pathway to the nucleus accumbens.
