Muscle memory, motor control, both of these terms may not have been investigated by humans thousands of years ago. But, it still developed and helped humans survive. Today, endocannabinoids are an exciting new field of research being investigated. Today, the role of the endocannabinoid system in motor control will be investigated.
What is Motor Control?
The way in which humans and animals use their brain to activate, coordinate, and propagate the muscles and limbs at their disposal to perform a movement is, motor control. To live in this world, adequate motor control is necessary and synergy amongst all the components of it is required. At its most basic level, motor control is the integration of sensory information from external stimuli and the inside of the body, to orchestrate the appropriate muscles and joints to produce an action. Motor control can be reflexive (involuntary & uncontrolled) or it can be controlled (voluntary).
How Does Motor Control Work?
For motor control to work it requires cooperation between the central nervous system & musculoskeletal system. It requires that a human or animal be able to : respond to stimuli, process information, coordinate, and perceive the external world.
Voluntary motor control, begins in the motor cortex of the brain. It is here where it is planned. It is in the motor cortex that there is a map of the body, termed “sensory homunculus”. A surgeon may decades ago was able to map this out during an open brain surgery and find that all the regions of the body could be activated to move by stimulating certain parts of this area in the brain.
Voluntary movement begins in the frontal lobe, the thought of it is sent to the middle region of the brain called the basal ganglia and also to the motor cortex on the dorsal medial aspect of the brain. The basal ganglia is called upon because it relays sensory information to the motor cortex, constantly notifying it of the external world and the internal world of the body. Scientists believe that the basal ganglia is necessary to initiate a planned movement as patients with Parkinson’s disease (deficient in the basal region) have trouble initiating planned movement.
While all this is happening, while the thought of movement began in the frontal lobe, and the basal ganglia and motor cortex relayed information and planning back-and-forth, the cerebellum was gearing up for action. The cerebellum is a circular organ just above the spine and below the occipital lobe. The cerebellum was gearing up to playing a critical role in motor control, it is responsible for using incoming sensory information to determine the direction, force, balance, and duration of a desired movement. Motor control works because while the movement is initiating, the cerebellum has a loop with the basal ganglia, sending and receiving information, and processing it in such a way to determine how a movement should be conducted so that it is crisp, fine tuned, and balanced. All the while, the muscle and joints are taking orders from above. The muscles and joints are constantly intaking signals, and sending them back, to modify even the simplest of movements.
What is The Role of The Endocannabinoid System in Motor Control?
To understand the role of the endocannabinoid system in motor control, the basal ganglia must be reviewed. The basal ganglia is a group of structures linked to the thalamus in the base of the brain, it is a bundle very important nerve ganglia, is involved in the coordination of movement, Scientists believe that endocannabinoids have a role in motor control because of the abundance of CB1, CB2, and VR1 receptors within the basal ganglia and cerebellum. A simple why would it be there, it must have a purpose?
However, due to the inhibitory nature of endocannabinoids, it is suspected that they may have the potential to alleviate motor symptoms and provide neuroprotections for nerves in a variety of neurological pathologies. For example, cannabinoids are implicated in the control of irregular motor movements as a result of having Parkinson’s, Multiple Sclerosis, and Alzheimer’s.
Can Endocannabinoid Deficiency Affect Motor Control?
This paragraph should answer:
- What are some ways the ECS can become dysfunctional in this system/process
- What are some conditions that may result from ECS deficiency in this system/process
A deficiency of endocannabinoid could worsen the situation for a patient diagnosed with any nervous system disorder affecting movement. Although, there is still much conflict on the effect of endocannabinoids on motor control, perhaps, the best example is this. Studies in animal models and patients with Parkinson’s disease have found that an imbalance in basal ganglia pathways is caused by dopaminergic-neuronal degeneration. Break down of the neurons that make dopamine. But, this imbalance is characterized by decreased activity of GABA producing neurons and hyperactivity of different striatal neurons. If cannabinoids are not produced in sufficient quantities then these movements could be uncontrolled, unnatural, and exaggerated. Even more so, if a patient has a movement disorder such as Parkinson’s disease. However, the endocannabinoid system is vast and affects many aspects of the body. It is for this reason that research must continue to uncover the nuances of the body and how the endocannabinoid system is implicated in them.