Rafe nuclei, anatomy and function

Rafe nuclei, anatomy and function

Surely you've ever heard of the serotonin, a neurotransmitter that has a lot to do with mood and whose lack is related to states such as depression. Serotonin is very important for our survival and well-being and today we talk about the brain structure that makes its creation possible: the Rafe nucleus.


  • 1 What is the core of the Rafe?
  • 2 Anatomy of the Rafe Nucleus
  • 3 What is the function of the Rafe nuclei?

What is the core of the Rafe?

The word "Rafe", in Greek, refers to a crest that separates two symmetrical areas of an organ or tissue. Thus, the core of Rafe is a set of groups of neurons that are in the midline of Brain stem. The brain stem, in turn, is made up of several very important areas such as the midbrain, the bridge and the spinal bulb and is responsible for communicating the spinal cord and nerves of the periphery with the different areas of the brain, in addition to participating in different very important functions such as the maintenance of breathing.

In this area rests the core of the Rafe next to structures as important as the bridge or the cerebellum. In addition, this nucleus is part of the reticular formation, one of the most primitive areas of the brain that is responsible for controlling sleep rhythms.

Anatomy of the Rafe Nucleus

The Rafe core is divided into six small cores. Some of these nuclei are located in the rostral zone, closer to the upper area of ​​the brainstem, while others are in the caudal group, the lowest zone.

In the rostral zone, 85% of brain serotonergic neurons are found. This area is composed of the Rafe pontis nucleus and the upper central nucleus, in the area of ​​the bridge and the Rafe dorsalis nucleus, in the midbrain area. These nuclei usually connect with the areas of the brain in which the superior functions are performed, such as the frontal areas, although the neurons of the dorsalis nucleus connect with numerous brain areas such as the orbitofrontal cortex or the hypothalamus.

In the caudal zone there are fewer serotonergic neurons and there is the nucleus of the Rafe magnus, in the area of ​​the bridge, the obscurus nucleus and the nucleus of the Rafe pallidus, of lesser extent, in the area of ​​the medulla oblongata. These nuclei in the lower zone of the brainstem They usually project to the spinal cord and brain stem.

What is the function of the Rafe nuclei?

The main function of these nuclei is the production of the serotonin. Serotonin is a main neurotransmitter for the proper functioning of the nervous system and manages to regulate mood by controlling negative emotions such as fear, aggressiveness or anxiety, as well as its lack can lead to disorders such as depression.

The nucleus of the Rafe synthesizes this neurotransmitter and sends it to the rest of the nervous system getting it to fulfill its mission. In addition, these nuclei contain other types of neurons, not only serotonergic cells, although these are concentrated here more than anywhere else in the brain.

This generation of serotonin, get maintain and regulate mood and control certain aggressive behaviors. When medicines such as SSRIs that inhibit the reuptake of serotonin are promoted, promoting their greater creation, psychological states such as depression are considerably reduced, this being a widely used treatment.

The neurons that transmit serotonin reach other parts of the brain stem and appear to participate in the regulation of the circadian rhythm that this large structure manages to control. Thus, the Rafe nucleus is also involved in the sleep-wake cycle regulation, working in accordance with the hypothalamus with which it will carry out a feedback on alert and wakefulness levels producing more or less serotonin.

It seems that in addition, the Rafe nuclei, especially the magnus nucleus and the dorsal nucleus, are involved in pain inhibition processes. The projections of the Rafe nuclei reach the spinal cord and there they inhibit the dorsal horn neurons that are responsible for transmitting pain information. Thus, the nervous system manages to regulate the intensity of this sensation. As we see, many are the tasks of this interesting structure of which, however, we still do not know all its functions and secrets to discover, as well as the neurotransmitter that is most associated with it: serotonin.

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