How the Limbic System Works: Functions of the Limbic System

The limbic system is a group or set of brain structures that control various body and brain functions. It is located on both sides of the thalamus in a brain region known as the forebrain, provides it with information about our emotions and memories. The thalamus functions like a processing center, transmitting data to the cerebral cortex, the largest part of the human brain, which acts as an "information hub," processing intelligence, personality, voluntary physical action, and other higher-order functions.

The limbic system influences the endocrine system, the glands that produce hormones that regulate many of our bodily functions. It also affects the autonomic nervous system, which controls some unconscious functions, like our thirst, hunger, heart rate, and biological clock, or circadian rhythm.

In turn, our environment and experiences can change our limbic system. Mental therapy, such as psychiatry, can also change the limbic system by helping us process memory and emotion differently.

Several different brain structures make up each part of the limbic system. While neuroscientists debate the exact number of parts in the group of structures, it generally includes:

• The amygdala: The amygdala is a pair of small, almond-shaped structures located in the brain’s left and right temporal lobes, which process long-term memory. The amygdala's role is to help the body connect memories to emotions, especially when the body is faced with a threatening situation.
• The hippocampus: The hippocampus is another pair of small structures that resemble seahorses, both located on either side of the brain. It helps store sensory information about experiences in order to form long-term memories, including spatial memory and spatial reasoning—how we remember where things are and where they, and we, are in relation to each other.
• The hypothalamus: The hypothalamus is another small, almond-shaped structure located in a region of the forebrain called the diencephalon, which rests between the thalamus and the brain stem, connecting the brain and spine. It assists the other parts of the limbic system in processing sensory information, like smell and taste. It's also connected to the pituitary gland. The two structures assist the endocrine system in producing hormones that maintain homeostasis—the regulation of blood pressure, internal heat, sleep, and hunger, among others.
• The basal ganglia: The basal ganglia are a group of nuclei located on both sides of the thalamus. These nuclei oversee many automatic functions, including eye movement and reading and our internal reward and pleasure responses.
• The cingulated gyrus: The cingular gyrus is part of the cingulated cortex, which is found above the nerve tract called the corpus callosum in the medial part of the cerebral cortex. It's one of many gyri, or folds in the brain, that connect with the limbic system and processes many emotional responses and decisions that affect communication and behavior.
• The fornix: The fornix is a bundle of nerves that transmit memory-forming neurotransmitters allowing us to remember people and places that can help us.

Other parts of the limbic system include the dentate gyrus, which may contribute to the formation of new memories; the parahippocampal gyrus, which assists in forming and retrieving memories of places and scenes olfactory bulbs, which provide sensory information through olfaction, or smell.

The functions of the limbic system affect many different physical, mental, and emotional responses, including:

• Emotion. Emotion is one of the primary functions of the limbic system. The amygdala connects emotion to memories and plays an important role in creating our “fight, flight, or freeze” response to stimuli that make us feel afraid or threatened. The hippocampus assigns sensory input, like a smell, taste, or feeling, to a memory. It’s responsible for recalling memories connected to eating a particular food and why we remember to avoid hot objects after being burned. The hypothalamus also plays a role in emotion by producing oxytocin, the “love” hormone that helps parents connect with newborn babies, and adrenocorticotropic, which manages our stress response.
• Memory. The limbic system’s processes assist both short- and long-term memory. The amygdala is essential to creating short-term memories and may be related to how we process memories based on social behavior. The hippocampus helps us store long-term memories linked to sense and emotion, which is called memory consolidation. Along with the cingulate gyrus, it assists in helping us complete navigational tasks.
• Motivation and reward. Research suggests that the ventral tegmental area (VTA), a neuron in the basal ganglia attached to the nucleus accumbens, produces dopamine. This neurotransmitter produces feelings of pleasure and can motivate us to learn and try new things.
• Automatic body functions. The hypothalamus and pituitary gland produce hormones that regulate many crucial body functions, mainly without our awareness. In addition to stress and reproduction, they monitor and adjust our body temperature, hunger, blood sugar, and blood pressure levels, our growth and development, sex drive, and even when we need to sleep and wake up.

Find something comfortable to sit or lie on, grab a MasterClass Annual Membership, and dial into the present moment with Jon Kabat-Zinn, the father of the Western mindfulness movement. From formal meditation exercises to examinations of the science behind mindfulness, Jon will prepare you for the most important practice of them all: life itself.