Brain twists: the 9 major folds of the brain
There are many folds in our brain, specifically our cerebral cortex. The so-called brain turns are along with the grooves that accompany them one of the things that attracts the most attention when we observe an encephalon from the outside, giving it a wrinkled appearance that nevertheless allows brain matter to be a compact mass.
These turns are not merely aesthetic: as brain matter they are, they participate in the various functions that our cortex performs. In this article we will see what are the cerebral twists and we will review the characteristics of some of the best known.
- Related article: "Parts of the human brain (and functions)"
What is a brain turn?
Let's start with a definition of what a brain turn is. We denominate cerebral turns to set of folds visible in our cerebral cortex , generated by bending over itself as the brain develops and allowing the brain to be larger, making the space it occupies much less than expected in case it has been extended.
Also called convolutions, the cerebral turns would be the part of the fold that protrudes, being the parts that remain inward the grooves. These structures are formed throughout the brain development of the fetus, not possessing them from the beginning. Little by little they will be observing more and more, until they can observe its presence throughout the entire cerebral cortex.
It's about protrusions of brain matter, specifically gray matter . This implies that the brain twists are formed mainly by glial cells and somas of neurons, which are the part of the neuron that emits the information that will later be sent through the axon to the next neuron or target organ.
Main brain twists
Considering that they occupy the entire surface of the cerebral cortex we should consider that there is a large number of cerebral twists. Each of them has different functions in the system . Then we will discuss some of the most important and known, although it must be borne in mind that there are many more than those that will be presented in this article.
1. Precentral rotation
Also called prerrolándica gyrus, this turn is located ahead of Rolando's fissure (That is, it would be more towards the face than said fissure). The brain matter that belongs to it corresponds to the primary motor area.
- Related article: "Cisura de Rolando: characteristics and areas that surround it"
2. Postcentral rotation
Unlike the precentral, the postcentral turn is located after or after the Rolando fissure. On this occasion, we would be facing a brain turn that would be part of the primary somatosensory cortex , linked to somatic perception and body sensitivity.
3. Jagged rotation
Circumvolution present in the lower part of the temporal lobe and forming part of the hippocampal formation, connecting it with the rest of the cortex. Specifically, it acts as bridge between entorhinal cortex and hippocampus . Its functions are linked to memory, spatial navigation and the integration of emotion in memories.
4. Cingulate twist
Like the previous one, this important brain turn has an important role in the integration and connection of the limbic system and the cerebral cortex . Located near the corpus callosum, it is associated with the perception of anxiety, pleasure, fear, initiation of goal-oriented behavior, voluntary movement, modulation of the voice or direction of attention and motivation.
- Maybe you're interested: "Cingulate (brain) rotation: anatomy and functions"
5. Angular turn
This is one of the best-known brain twists, especially for its involvement in language and mathematics. It helps to allow the production and comprehension of sentences with meaning, as well as to understand written language. It is also involved in the arithmetic capacity and the interpretation of quantities, in addition to link to aspects such as behavioral control, symbol coding and creativity .
6. Supramarginal rotation
Present in the parietal lobe above the Sylvian fissure, this is another of the best-known cerebral gyrations. One of the most known functions is its involvement at the time of allow the ability of literacy , integrating the information of the visual and auditory pathways. Also the working memory or tactile perception are influenced by this convolution.
7. Turning for a hippocampus
With an important role in regard to memory, the para-hippocampal rotation can be found around the hippocampus.The function most associated with this turnaround is that of store and retrieve stored information .
8. Fusiform rotation
The fusiform gyrus, which is located between the temporal and the occipital and which can be divided into two subgroups called occipitotemporal lateral and medial rotation, seems to be involved in aspects such as visual recognition of words and faces , as well as the processing of color information or the differentiation between memory and non-memory.
It is also associated with the identification of categories, the deduction and the understanding of figurative language.
9. Lingual rotation
This cerebral rotation is found next to the parahippocampal and is in contact with the lateral and calcarine sulci, having a relevant role in the processing of visual information and transformation of graphic information into auditory information in reading .
As we have mentioned, the ones mentioned so far are only a few of the very different turns present in the brain. In addition to the above we can find, among others, the following.
- Island turns: Long and Short.
- Occipital turns
- Upper front turn.
- Front half turn.
- Lower front turn .
- Upper temporal rotation.
- Average time rotation.
- Lower temporal rotation.
- Whirling twist
- Orbital rotation .
- Triangular turn
- Opercular rotation.
- I turn straight.
- Olfactory rotation .
- Precuneiform rotation.
- Cuneiform twist.
- Paraterminal rotation.
- Clark, D.L .; Boutros, N.N. and Méndez, M.F. (2012). The brain and behavior: neuroanatomy for psychologists. 2nd edition. The Modern Manual. Mexico.
- Kandel, E.R .; Schwartz, J.H .; Jessell, T.M. (2001). Principles of Neuroscience. Madrid: McGraw Hill.
- Snell, R.S. (1999). Clinical Neuroanatomy. Buenos Aires: Editorial Medica Panamericana, S.A: 267.