The diencephalon is the smallest but important region of the brain located in the center. It relays sensory information between parts of the nervous system and helps interpret signals more accurately. It consists of four sections - the hypothalamus regulates hormones and homeostasis, the epithalamus contains the pineal gland and assists with smell and sleep, the subthalamus connects to motor functions, and the thalamus transmits all sensory information except smell and regulates circadian rhythms. The pituitary gland's posterior portion is also part of the diencephalon.

1. Diencephalon Function: Bringing All
Your Senses Together
Your brain is an intricate structure that consists of four regions. Each of these regions differs
from the others in terms of location, function, and size.
The smallest of these is the diencephalon, which accounts for no more than 2% of the total
brain weight and measures just 2.2 inches in length.
Don’t be fooled by its size, though, as the diencephalon plays a part in many important brain
processes.
In this article, we will discuss the main diencephalon function and answer some common
questions about this small yet important part of the brain.

2. Where Is The Diencephalon Located In The Brain?
The diencephalon is located at the center of the brain, and its name (Greek for “between-
brain”) reflects that.

3. It’s surrounded by the brain stem and cerebellum on the bottom and the cerebral cortex on
top. It seamlessly continues on to the midbrain on the bottom-right and borders with the
corpus callosum on the top-left.
Due to its specific position in the brain as well as its small size, the diencephalon is mostly
obscured from view. Looking at a 3D model of the brain, you may only see the very bottom
of the diencephalon. To see this brain region in full, it is necessary to take a cross-section of
the brain.
What Is The Function Of The Diencephalon In The Brain?
On the whole, the main function of the diencephalon is to relay sensory
information between different parts of the central nervous system. It also helps the brain
interpret signals from the nervous system more accurately.
This region of the brain consists of four sections, each with its own set of functions.
Starting from the bottom, there is the almond-shaped hypothalamus, which is responsible
for many functions of the autonomic nervous system. This section is in charge of hormone
production and maintaining homeostasis. It also regulates blood pressure and body
temperature.
Next up is the epithalamus, which is home to the pineal gland. This endocrine gland
is responsible for the production of melatonin, a hormone that helps control your body’s
circadian rhythms. The epithalamus also regulates the sleep cycle. In addition, it also assists
in sense of smell.
Moving up, there is the subthalamus, which has a direct connection to the basal ganglia, a
large group of nuclei located in the cerebrum. Their primary functions include motor control
and motor learning. Because it’s connected to the basal ganglia, the subthalamus plays an
assistive role in these processes.
Finally, there is the thalamus, the largest section of the diencephalon. Like the epithalamus,
this section is in charge of regulating your body’s circadian rhythms. More importantly, it
is responsible for transmitting information obtained from all senses except for smell, which is
the job of the epithalamus.

4. Is The Diencephalon Part Of The Midbrain?
As we have already explained, the diencephalon seamlessly continues on to the midbrain,
which makes them appear as if they are the same structure. However, the diencephalon
is not part of the midbrain.
Instead, the midbrain is part of another main brain section. Together with the medulla
oblongata and the pons, the midbrain constitutes the brain stem, which is located just below
the diencephalon.
Is The Pituitary Gland Part Of The Diencephalon?
The pituitary gland is, in fact, part of the diencephalon.
However, it’s important to note that only the posterior of this gland is considered part of the
diencephalon. It connects to the hypothalamus through a small tube known as the pituitary
stalk.