A Body Mind Workers Neuroanatomical Approach to Anxiety: PART 1
The amygdaloid nucleus (amygdala) is located in the temporal lobe.
The amygdala has neural connections to the basal ganglia, an area of the brain important for smooth, coordinated and controlled skeletal movement. However, the amygdala is anatomically and functionally part of the limbic system.
As its most simplistic description, the limbic system is an area of the brain integral to emotions. An emotion can be described as a subjective sensation, most notably of anger, distress, excitement, fear, happiness, hate, love, or sadness. The expression of emotion is accompanied by a physiological and somatic ‘state change’.
The specific areas of the limbic system are sometimes described inconsistently among neuroanatomists, due to the widespread and complex nature of the connections. However, two of the most important parts of the limbic system are the ‘hypocampal formation’ and the ‘amygdala’.
The hippocampal formation is primarily tasked with the conversion and consolidation of short-term memory into long-term memory, whereas the amygdala regulates emotional expression via modulation of the hypothalamus.
A key function of the amygdala is its involvement in the control of the autonomic nervous system, which are the portions of the nervous system controlling unconscious processes such as respiration, heart rate, digestive processes etc. The modulation of the autonomic nervous system is achieved through reciprocal projections between the amygdala and hypothalamus, in addition to direct descending pathways that terminate in the brain stem.
The hypothalamus is an area of the brain responsible for the production of many of the body’s essential hormones. The hormones from the hypothalamus govern physiologic functions such as temperature regulation, thirst, hunger, sleep, mood, sex drive, and the release of other hormones within the body. This area of the brain also houses the pituitary gland – often referred to as the ‘Master Gland’.
Anatomically, the modulation of the hypothalamus is achieved via the ‘stria terminalis’ and ‘amygdaloid’ pathways.
The amygdala is remarkable as it receives sensory input from widespread areas of the nervous system. This includes somatosensory, visual, auditory, olfactory (smell) and gustatory (taste) input. These connections mean the amygdala is constantly updated by input from all of our senses.
The autonomic nervous system is mediated by the amygdala through instinct. The amygdala utilises past experiences, and via the basolateral nucleus has reciprocal projections with the sensory association areas of all four lobes and is associated with the processing of input related to past experiences and in particular, suffering. The amygdala also has reciprocal connections with the insula, an area of the brain that interprets information and plays an important role in creating the perception of pain.
In conclusion, the amygdala is a primitive cluster of nuclei in the brain that controls our emotional responses, and is driven by instinct. The amygdala receives constant, ongoing information from all of the brains lobes about input from all of our senses simultaneously. When we experience a context that is perceived as a threat, our amygdala stimulates one of a number of responses, most people are only aware of the fight of flight response, but this also includes flock, freeze, fawn, feast and famine. Each one causing a cascade of chemical events designed to prepare us for an immediate threat.
Clinical research has shown a strong correlation between individuals suffering with conditions such as anxiety, depression and chronic pain, with an increased activity, connectivity, and even anatomical size of the amygdala itself.
If only there were a light, fun, and safe way to influence with amygdala…
Stay tuned for part 2!
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