What is the limbic system?
A complex set of interconnected structures of the brain involved with emotion, behavior, motivation, the regulation of memories and hormones, sexual arousal, circadian rhythms, olfation, and is generally considered the interface between emotional states and memories of physical stimuli. It is the (oldest) part of the brain involved when it comes to behaviors we need for survival: feeding, reproduction and caring for our young, and fight or flight responses.
This complex structure sits on top of the brain stem and is made up of the hippocampus, amygdala, part of the thalamus and the hypothalamus, and several regions of the cerebral cortex. It has approximately 34 structures and 53 pathways, and since aromas, emotions, and memories all meet here, we know why smell can trigger specific memories and emotions.
Damage to the limbic system can result in an inability to experience pleasure and emotions.
Essential oils and their interactions with the limbic system
When inhaling an essential oil, odiferous molecules enter the nose and travel to the top of the nasal cavity where 50 million smell receptors occupy an area in the olfactory system. When an odor molecule penetrates these receptors it sends a signal to the olfactory bulb which is a major structure within the limbic system.
Essential oils have a powerful effect on both the hypothalamus and pituitary gland, which are stimulated to produce neurochemicals and hormones that balance and regulate various systems within the body, such as the endocrine, immune, and nervous system. Hormones are like chemical messengers that target specific cells in the body, and their arrival in those cells will trigger a particular response. Therefore, when we inhale an essential oil with sedating or stimulating, properties it will produce a response in the appropriate system, and sometimes in several systems simultaneously.
Precise and adapted use of essential oils can cause various parts of the limbic system to spring into action, triggering the release of neurochemicals and hormones that for instance, will slow the heart rate, regulate blood pressure, and stimulate the immune system. For example, serotonin produces a relaxing, soothing effect while certain endorphins inhibit pain and increase sexual arousal. This is why certain aromas put us on guard while others calm us down.
Ways aromatherapy alters and impacts the limbic system to improve our wellbeing.
Modern science has now recognized the interrelationship between psychology and fragrance by studying the emotions produced when odors activate the olfactory pathways leading to the limbic system.
Research has now scientifically proven that essential oils can change mood, behavior, and productivity, and has determined which neurotransmitters were released to cause this effect.
We know that stress causes adrenalin and cortisol to be produced by the body as part of the "fight or flight" response which is essential for survival, but damaging over an extended period of time because these chemicals suppress the immune defenses. As a result, aromatherapy can be used as a tool to limit this stress response and restore balance.
Aromatherapy changes our brain’s limbic system depending on the aromas:
Reduce pain and relax the body and muscles, which can subsequently help you fall asleep quicker. Eucalyptus, ginger, lavender, black pepper oil, and marjoram are commonly recommended for soreness.
Boost and uplift the mood and alleviate dark thoughts. Neroli, Grapefruit, Rose, and Frankinscense.
Lower stress levels: Chamomile and lavender are must-haves. Both promote calmness and decrease tensions. Additionally, you can use Valerian, Jasmine, Bergamot, Holy Basil, or lemon balm.
Improve emotional connection, and increase libido and sensuality: spicy notes of clove and orange, rose, jasmine, and sandalwood make us feel more emotionally connected.
Enhance focus and alertness: Rosemary, Clary sage, lemon, and peppermint are excellent to sharpen concentration, boost motivation and energize the brain.
(1) Fung, T., Lau, B., Ngai, S., & Tsang, H. (2021). Therapeutic Effect and Mechanisms of Essential Oils in Mood Disorders: Interaction between the Nervous and Respiratory Systems. International journal of molecular sciences, 22(9), 4844. https://doi.org/10.3390/ijms22094844 (2)Zhang, Y., Wu, Y., Chen, T., Yao, L., Liu, J., Pan, X., Hu, Y., Zhao, A., Xie, G., & Jia, W. (2013). Assessing the metabolic effects of aromatherapy in human volunteers. Evidence-based complementary and alternative medicine : eCAM, 2013, 356381. https://doi.org/10.1155/2013/356381