We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.
Conditions

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

What Is the Medial Geniculate Nucleus?

By S. Berger
Updated: Mar 03, 2024
Views: 18,462
References
Share

Incoming sensory input is routed to the cerebral cortex through a structure called the thalamus. Many distinct groups of neurons comprise the thalamus, and one of these is the medial geniculate nucleus (MGN), also called the medial geniculate body. The MGN is involved in auditory processing, and in directing one's attention toward specific auditory stimuli. Conditioned fear responses involving auditory stimuli also use this structure in the brain.

Several subnuclei exist inside of the medial geniculate nucleus, each with their own specialized neurons and functions. These regions have multiple sources of input, but all of them receive information from the inferior colliculus, the initial area that auditory information is routed to from the brain. Additionally, they all send projections to the auditory cortex, and other areas of the cerebrum. The first subarea, the ventral subnucleus, contains cells that activate in response to certain sound frequencies. Information on the intensity of sounds, and how frequency and intensity differs between the ears, is also relayed to the cerebrum through these specific cells.

Another subnucleus of the medial geniculate nucleus is the dorsal subnucleus. Some cells in this area seem to respond to both sounds and other sensory input, such as touch. They may also play a role in processing complex sounds, since they respond to a variety of frequencies. This area seems to be capable of modification by learning.

The third main subarea of the medial geniculate nucleus is the medial subnucleus. Cells in this area process sound duration and loudness. They also seem to respond to small ranges of frequencies, instead of just one frequency. Other sensory stimuli, such as visual information, seems to influence how these cells respond to sound.

Many cells in the medial geniculate nucleus send projections to the amygdala, a brain region involved in both learning and expressing fear responses. Activation of cells in the MGN that produce the chemical neurotransmitter glutamate allow learned auditory fear responses to be expressed. These same cells also seem to be involved in the extinction of the fear response.

Cells in the MGN that respond to auditory stress do so in a specific pattern. These cells are involved in the creation of certain ribonucleic acid (RNA) called c-fos. This process seems to result in the production of stress hormones, called corticosteroids, by the hypothalamus. Learning fear responses seems to depend, at least in part, on this initial RNA induction and stress response.

Share
The Health Board is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Link to Sources

Related Articles

Discussion Comments
Share
https://www.thehealthboard.com/what-is-the-medial-geniculate-nucleus.htm
Copy this link
The Health Board, in your inbox

Our latest articles, guides, and more, delivered daily.

The Health Board, in your inbox

Our latest articles, guides, and more, delivered daily.