Healing the Brain Through Nature

Rewiring & Rewilding

Written by Herbalist Sophia Laverdiere

There is a part of the human brain that has not evolved since the earliest hominids. Since it has remained unchanged, we can infer that it must be a key component to making up what we call being a human (Swenson). This section is called the Limbic System. The Limbic system is a complex set of structures made up of the hypothalamus, the hippocampus, and the amygdala.

As we begin to experience life, these parts of the brain behave much like a computer. The synapse that takes place, stores information within the certain structures that are responsible for processing our reality.

In specific, the synergy of the structures stores highly charged emotional memories, processes our sense of smell, regulates our mood, sleep cycles, and appetite (Swenson). In terms of our society, we tend to function with lack of many things; sleep, control of our emotions, and the ability to process events that have affected us. That is why I believe healing the limbic system, with the use of botanicals, is imperative in modern times because of our increased stress levels and societal shift away from nature.

To understand the limbic system we must take a look at the set of structures that make it up. The limbic system contains the hypothalamus, anterior thalamus (cingulate gyrus), hippocampus, amygdala, septal nuclei, olfactory cortex, and portions of the basal ganglia (LeDoux). It is noted from numerous sources, that the structures that make up the limbic system are not set in stone. There are many things we do not know about the brain, but through science we have noted that these portions constitute the emotional brain. They are in charge of very specific jobs that program our response to the world we know. Taking a closer look at each portion of the brain, we can identify where and how our reality is stored.

According to neuroscientist Joseph Ledoux, the hypothalamus evaluates the emotional relevance of environmental events. “Its job is to send signals to the brainstem, so that emotions can be expressed as bodily responses, and to the cortex, so that emotions can be experienced as subjective states” (LeDoux). In addition, the amygdala is a critical center for coordinating behavioral, autonomic and endocrine responses to environmental stimuli, especially those with emotional content. The amygdala responds to a variety of emotional stimuli, but mostly those related to fear and anxiety.

Often the olfactory cortex makes a strong connection with the anterior portions of the temporal lobe and the amygdala. Essentially, our olfactory system is set up on smell taken in by our nose. The olfactory cortex projects to the amygdala and can influence emotional and endocrine reactions particularly in connection with the hypothalamus (Swenson). Another portion of the brain that works directly with the amygdala is the hippocampus. The hippocampus has several functions. It helps control corticosteroid production and has significant contribution to understanding spatial relations within the environment. Additionally, the hippocampus is critically involved in many declarative memory functions including short term and long term memory. (Swenson)

Keeping in mind the roles of each structure, we can infer that in modern society our increased stress levels have affected these parts of the brain. According to the American Psychological Association, half of Americans report their stress levels have increased in the last five years. They also report that nearly two- thirds of all visits to family physicians are due to stress related symptoms. A result of the rising stress levels is the emotions, fear and anxiety (Smalley). The best biological model of anxiety and the fear based response is by previously mentioned, neuroscientist Joseph LeDoux. He summarizes that while fear is an acute stress response to immediate danger, anxiety is a stress response when no danger is present.

In addition, we can all admit that the world we live in is fast paced and there is little time to put ourselves first. The demands placed upon us just keep getting more stressful and this may be influenced by our societal shift away from nature. In the book, Reclaiming the Wild Soul, the author mentions that for hundreds of generations humanity’s primary relationship was with the Earth. Our ancestors engaged with the land, the water, and the creatures around them. About 10,000 years ago, we began the transformation from hunter-gatherers to agriculturalists, thus shifting our primary social form of organization. Before this, life must have been brutal at times. However, from many historical accounts we can see our ancestors never questioning their sense of belonging to a community of life which was inextricably entwined with nature (Thompson).

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In losing our intimate relationship with the Earth, we modern humans have suffered a particular trauma that has caused our wild souls to split off. Here, we can see where the accounts of increased stress levels might tie in.

In restoring the natural relationship we have with the Earth, I believe we can heal our emotions and traumas that tie into the limbic system. A quote found in the book Reclaiming the Wild Soul, by cultural historian Thomas Berry helps support this, “Beyond our genetic coding, we need to go to the earth, as the source whence we came, and ask for her guidance, for the earth carries the psychic structure as well as the physical form of every living being upon the planet.” In connection to this, by being outdoors and simply using our nose to take in the fresh scents of the surrounding area, we can relax our body through our olfactory cortex and amygdala. This very practice is of mindfulness. Through mindfulness in nature we can process our emotions freely, no longer suppressing them inside (Smalley).

In addition to the simple act of just being with nature, we can also take medicinal plants into our bodies to support our emotions and processing. Through studying the mechanism of action within these plant medicines, we can see how they work directly through our limbic system. St. John’s Wort, Hypercium perforatum, has a wide reputation as a regenerative nerve tonic for both psychiatric and neurologic conditions. “It is directly calming to the limbic system and, as numerous studies have shown, is a powerful adjunct in mild to moderate depression” (Francis). According to Bridget Mars, Fresh Milky Oats, Avena sativa, nourishes the limbic system and motor ganglia, increasing energy levels and sense of well being (Mars). In addition, after referencing literature put out by the American Herbalist Guild, many of the plants that are aromatic (containing volatile oils) help heal the limbic system (Richey). Botanicals such as lavender, rosemary, and lemon balm, are noted for their mood restorative effects on the body when taken internally. There is also a connection with the volatile oils found within these plants and their effect on the olfactory bulb, which is directly linked to the amygdala in the limbic system.

Healing the limbic system, with the use of botanicals, is imperative in modern times because of our increased stress levels and societal shift away from nature. By stepping back into the healing hands of nature, we can take the necessary steps to heal our emotions, which in return will better our lives.


Bibliography

  1. of a book written by more than one author:

Heller, Laurence and LaPierre, Aline, Healing Developmental Trauma, North Atlantic Books Berkeley, (2012).

     b. of  a book written by one author:

    Pert, Candace, Why You Feel The Way You Feel- Molecules of Emotion, Scribner   

    New York, (2003).


Works Cited

Francis, Deborah, R.N, N.D. "Nervous - Nourishing the Nerves - Specific Medicines." Medical Herbalism: Clinical Articles and Case Studies (n.d.): n. pag. Medherb.com. Paul Bergner, 2001. Web.

LeDoux, Joseph. The Emotional Brain, Fear, and the Amygdala. Thesis. Center for Neural Science, New York University, New York., 2002. N.p.: New York U, 2002. 727-38. The Emotional Brain, Fear, and the Amygdala. Center for Neural Science, 1 Oct. 2002. Web.

Mars, Brigitte, and Chrystle Fiedler. The Home Reference to Holistic Health & Healing: Easy-to-use Natural Remedies, Herbs, Flower Essences, Essential Oils, Supplements, and Therapeutic Practices for Health, Happiness, and Well-being. N.p.: Fair Winds, 2015. Print.

Richey, Holli, RH (AHG). "Emotionally Focused Herbal Therapy." (n.d.): n. pag. Hollirichey.com. Center for Integrative Medicine. Web.

Smalley, Susan L., and Diana Winston. Fully Present: The Science, Art and Practice of Mindfulness. N.p.: DaCapo, 2010. Print.

Swenson, Rand, MD. "Chapter 9 - Limbic System." Chapter 9: Limbic System. N.p., n.d. Web.

Thompson, Mary Reynolds. Reclaiming the Wild Soul: How Earth's Landscapes Restore Us to Wholeness. N.p.: White Cloud, 2014. Print.