Welcome to 2 minute neuroscience, where I simplistically explain neuroscience topics
in 2 minutes or less.
In this installment I will discuss directional terms in neuroscience.
There are several terms that we use to indicate direction in neuroscience.
Some are very straightforward.
For example, superior always means towards the top of the head, inferior always means
towards the feet.
Likewise, anterior always refers to the front of the body or the brain, while posterior
always refers to the back of the body or the brain.
There are also some terms, however, like dorsal and ventral, that change their meaning depending
on whether we are referring to the brain or the spinal cord.
When used for animals that move through the world horizontally, dorsal refers to the back
and ventral refers to the abdominal region.
With humans, the same usage applies when we are looking at the spinal cord.
At the junction between the top of the brainstem and the diencephalon, however, the axis shifts
due to the fact that humans walk upright.
Above this level dorsal refers to the superior portion of the brain and ventral refers to
the inferior portion.
A similar situation occurs with the terms rostral and caudal.
Rostral means towards the nose and caudal means towards the tail.
In animals that swim or walk on all fours these orientations are consistent, but in
humans they shift at the brainstem-diencephalon junction.
At the level of the spinal cord, rostral points up towards the head while caudal points down
towards the end of the cord.
In the brain, however, rostral points towards the anterior part of the brain while caudal
points toward the posterior part of the brain.
The brain can also be examined on three different planes, and these planes are used to describe
ways the brain is often sliced into sections for examination.
A sagittal section is seen when a slice down the middle of the brain divides the brain
into two separate halves.
A horizontal or transverse section is made by slicing the brain perpendicular to the
long axis of the body.
A coronal or frontal section is seen when a slice is made parallel to the long axis
of the body.
When looking at the brain or spinal cord in any orientation, the parts of the brain that
are closer to the midline are called medial, while those that are closer to the sides are