The midbrain (also known as the mesencephalon) is a vital part of the central nervous system (CNS) and is located in the brainstem near the junction of the diencephalon and the hindbrain. It is responsible for various functions, including motor coordination, auditory and visual reflexes, and controlling the sleep/wake cycle. The midbrain is often referred to as the “little brain” due to its small size. It is made up of several structures, including the tectum, tegmentum, and the cerebral peduncles. The tectum is made up of two structures, the superior and inferior colliculi, which are responsible for auditory and visual reflexes, respectively. The tegmentum is made up of several different nuclei and is responsible for various motor functions. Finally, the cerebral peduncles are responsible for connecting the midbrain to other structures in the brain, such as the thalamus and the cerebellum.
In humans, the midbrain is involved in a variety of functions, including motor control, auditory and visual reflexes, and regulation of the sleep/wake cycle. It is also involved in reward processing and decision-making. Damage to the midbrain can cause a variety of symptoms, including vision and hearing problems, tremors, and cognitive deficits.
Recent evidence suggests that the midbrain is also involved in emotion and social behavior. Studies have shown that the midbrain is involved in processing facial expressions, especially those of fear and disgust. It is also implicated in reward processing and decision-making, and it is thought to be the location of the dopamine reward system.
Given its importance to the CNS, it is important to better understand the anatomy and functions of the midbrain. To that end, further research is needed to increase our understanding of the midbrain and its role in various neurological disorders.
References:
Kang, Y., & Dong, M. (2019). Anatomy and functions of the midbrain. Frontiers in Neuroscience, 13, 583. https://doi.org/10.3389/fnins.2019.00583
Kurylo, A. (2020). Midbrain: Anatomy, function, and clinical significance. Medscape. Retrieved from https://emedicine.medscape.com/article/1913947-overview#a4
Mugnaini, M. (2019). The midbrain. Retrieved from https://www.verywellhealth.com/the-midbrain-2795310