Why You Should Be Thanking Your Cerebellum

Why You Should Be Thanking Your Cerebellum

Learn about the structure and functions of this amazing patch of brain tissue.

Cerebellum is a Latin word that means ‘little brain’. This term refers to its distinctive appearance compared to the rest of the brain. The cerebellum is a wrinkled, cauliflower-shaped brain structure located at the base of the skull. It looks like it could be a second brain and in fact, it is in some ways. For example, it has more total neurons than every other part of the brain combined. These neurons are organized in a way that creates tremendous processing power which is also a specific feature of the cerebellum. Though on the surface it seems like the cerebellum could operate just fine on its own, it is very much one part of a whole. It’s highly connected with many other areas of the brain and serves an important role in a variety of brain functions, most notably motor control.

Anatomy of the Cerebellum

The structure of the cerebellum is really quite exquisite. It’s complex yet remarkably orderly, and if you ever have the pleasure of looking at cerebellar tissue under a microscope, you’ll notice that the cell types that comprise it are strikingly beautiful. Fully describing the anatomical organization of the cerebellum could fill up an entire book, so we’ll just stick with the basics.

First, let’s start with the anatomical structures we can see with the naked eye. If you were to look at a cerebellum, you would notice that it is divided into two hemispheres connected by a central structure called the vermis (Latin for worm). The surface of the cerebellar hemispheres is characterized by a series of ridges or folds, called folia, which increase the surface area of the cerebellum and allow for greater numbers of neurons. These folia are separated by deep grooves, called fissures, which divide the cerebellum into several lobes (Kandel et al., 2000).

The cerebellum can be divided into three main lobes: the anterior lobe, the posterior lobe, and the flocculonodular lobe. The anterior lobe is the largest and is responsible for controlling movements of the limbs and body. The posterior lobe is involved in the coordination of movements and receives input from the cerebral cortex. The flocculonodular lobe is located at the bottom of the cerebellum and is involved in the coordination of eye movements (Kandel et al., 2000).

“I would not put a thief in my mouth to steal my brains.”
― William Shakespeare

Functions of the Cerebellum

The cerebellum is critical for a variety of functions and may be involved in more functions than are typically ascribed to it. Below are a few of the more well-established functions of the cerebellum (Rapoport et al., 2000).

● Temporal prediction

● Balance

● Proprioception

● Motor coordination

● Spatial orientation

● Generating large force at movement execution

● Motor planning

● Posture

● Speech

The Role of the Cerebellum in Balance

The cerebellum plays a crucial role in maintaining balance and coordination of movements. It receives input from sensory organs such as the inner ear, visual system, and proprioceptive system (which detects the position and movement of body parts), and integrates this information to coordinate and adjust body movements (Morton & Bastian, 2004).

The cerebellum uses this sensory input to generate motor commands that adjust the activity of muscles, tendons, and joints to maintain posture and balance. For example, when a person tilts forward, the cerebellum sends signals to the muscles in the legs and back to adjust their activity and prevent the person from falling.

The cerebellum also works in conjunction with other parts of the brain, such as the vestibular system and the brainstem, to control balance and posture. Together, these systems enable us to maintain balance and stability while standing, walking, or performing other movements (Barmack & Pettorossi, 2021).

The Role of the Cerebellum in Memory

While the cerebellum is primarily known for its role in motor coordination and balance, functional imaging research suggests that it also plays a role in some aspects of memory (Desmond & Fiez, 1998). Specifically, studies show that the cerebellum contributes to working memory, implicit memory, and explicit memory. Let’s break down what each of these types of memory is.

Working Memory

Working memory is generally defined as the ability to hold and manipulate a small amount of information. This capacity facilitates comprehension, problem-solving, reasoning, and planning.

Implicit Memory

Implicit memories are unconscious and often unintentionally created. Learning a new skill such as roller skating is an example of implicit memory.

Explicit Memory

Explicit memory is basically the opposite of implicit memory. These are memories that are created consciously and that can be described verbally. A memory of an important event is an example of explicit memory.

In Sum

The cerebellum is a unique and interesting brain structure with a plethora of important functions. It supports fine motor control, motor timing, walking, speech, attention, posture, spatial orientation, balance, and motor planning – just to name a few. It also has a highly organized structure and immense processing power. It comprises more neurons than all other brain regions combined even though it only occupies 10% of the total brain volume.

References

● Barmack, N. H., & Pettorossi, V. E. (2021). Adaptive balance in posterior cerebellum. Frontiers in Neurology, 12, 635259.

● Kandel, E. R., Schwartz, J. H., Jessell, T. M., Siegelbaum, S., Hudspeth, A. J., & Mack, S. (Eds.). (2000). Principles of neural science (Vol. 4, pp. 833-850). New York: McGraw-hill.

● Morton, S. M., & Bastian, A. J. (2004). Cerebellar control of balance and locomotion. The neuroscientist, 10(3), 247-259.

● Rapoport, M., van Reekum, R., & Mayberg, H. (2000). The role of the cerebellum in cognition and behavior: a selective review. The Journal of neuropsychiatry and clinical neurosciences, 12(2), 193-198