Triune brain: Difference between revisions

Revision as of 20:55, 9 February 2025

Theory of brain evolution

The triune brain is a model of the evolution of the vertebrate forebrain and behavior, proposed by neuroscientist Paul D. MacLean in the 1960s. The model suggests that the human brain is composed of three distinct layers that reflect its evolutionary history.

Overview

The triune brain model divides the brain into three parts:

The reptilian complex, or "R-complex", which includes the basal ganglia. This part of the brain is thought to be responsible for instinctual behaviors involved in aggression, dominance, territoriality, and ritual displays.

The paleomammalian complex, or "limbic system", which includes structures such as the hippocampus, amygdala, and hypothalamus. This layer is associated with emotions, memories, and social behaviors.

The neomammalian complex, or "neocortex", which is unique to higher mammals, particularly primates. It is involved in higher-order brain functions such as sensory perception, generation of motor commands, spatial reasoning, conscious thought, and language.

Historical context

MacLean's model was developed during a time when the field of neuroscience was rapidly expanding. It provided a framework for understanding the evolutionary development of the brain and its functions. The triune brain theory was influential in the fields of psychology, psychiatry, and neurobiology.

Criticism and current status

While the triune brain model was popular for many years, it has been criticized for oversimplifying the complexity of brain evolution and function. Modern neuroscience has shown that brain functions are not as compartmentalized as the model suggests. The model is now considered outdated, but it remains a useful heuristic for understanding some aspects of brain evolution and behavior.

Related pages

References

MacLean, P. D. (1990). The Triune Brain in Evolution: Role in Paleocerebral Functions. Springer.
Panksepp, J. (1998). Affective Neuroscience: The Foundations of Human and Animal Emotions. Oxford University Press.
LeDoux, J. (1996). The Emotional Brain: The Mysterious Underpinnings of Emotional Life. Simon & Schuster.

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-'''Toxic shock syndrome toxin''' (TSST) is a [[superantigen]] produced by certain strains of [[Staphylococcus aureus]]. It is one of the causative agents of [[toxic shock syndrome]] (TSS).
+{{Short description|Theory of brain evolution}}
+{{Use dmy dates|date=October 2023}}
+[[File:Triune brain.png|thumb|Diagram of the triune brain model]]
+[[File:Comparative evolution of the striatum and pallium in vertebrates.png|thumb|Comparative evolution of the striatum and pallium in vertebrates]]
+The '''triune brain''' is a model of the evolution of the vertebrate forebrain and behavior, proposed by neuroscientist [[Paul D. MacLean]] in the 1960s. The model suggests that the human brain is composed of three distinct layers that reflect its evolutionary history.
 ==Overview==
-TSST is a potent [[toxin]] that can cause severe illness in humans. It is produced by certain strains of the bacterium Staphylococcus aureus, which is commonly found on the skin and in the nose of healthy individuals. However, when the bacteria multiply and produce the toxin, it can lead to toxic shock syndrome, a severe and potentially life-threatening illness.
+The triune brain model divides the brain into three parts:
+* The '''reptilian complex''', or "R-complex", which includes the [[basal ganglia]]. This part of the brain is thought to be responsible for instinctual behaviors involved in aggression, dominance, territoriality, and ritual displays.
+* The '''paleomammalian complex''', or "limbic system", which includes structures such as the [[hippocampus]], [[amygdala]], and [[hypothalamus]]. This layer is associated with emotions, memories, and social behaviors.
-==Structure and Function==
+* The '''neomammalian complex''', or "neocortex", which is unique to higher mammals, particularly [[primates]]. It is involved in higher-order brain functions such as sensory perception, generation of motor commands, spatial reasoning, conscious thought, and language.
-TSST is a single polypeptide chain with a molecular weight of approximately 22,000 daltons. It is a [[superantigen]], meaning it has the ability to activate a large proportion of the body's [[T cells]], leading to a massive release of [[cytokines]]. This cytokine release is responsible for the symptoms of toxic shock syndrome.
-==Clinical Significance==
+==Historical context==
-TSST is one of the causative agents of toxic shock syndrome. This syndrome is characterized by sudden onset of fever, chills, vomiting, diarrhea, muscle aches and rash. It can rapidly progress to severe and life-threatening complications such as shock and organ failure. Early recognition and treatment of toxic shock syndrome is critical to prevent severe illness and death.
+MacLean's model was developed during a time when the field of [[neuroscience]] was rapidly expanding. It provided a framework for understanding the evolutionary development of the brain and its functions. The triune brain theory was influential in the fields of [[psychology]], [[psychiatry]], and [[neurobiology]].
-==Prevention and Treatment==
+==Criticism and current status==
-Prevention of toxic shock syndrome involves proper hygiene practices to prevent Staphylococcus aureus infection. Treatment typically involves antibiotics to kill the bacteria, and supportive care to manage symptoms and complications.
+While the triune brain model was popular for many years, it has been criticized for oversimplifying the complexity of brain evolution and function. Modern neuroscience has shown that brain functions are not as compartmentalized as the model suggests. The model is now considered outdated, but it remains a useful heuristic for understanding some aspects of brain evolution and behavior.
-==See Also==
+==Related pages==
-* [[Staphylococcus aureus]]
+* [[Brain evolution]]
-* [[Toxic shock syndrome]]
+* [[Limbic system]]
-* [[Superantigen]]
+* [[Neocortex]]
-* [[Cytokines]]
+* [[Basal ganglia]]
-[[Category:Toxins]]
+==References==
-[[Category:Bacterial diseases]]
+* MacLean, P. D. (1990). ''The Triune Brain in Evolution: Role in Paleocerebral Functions''. Springer.
-[[Category:Infectious diseases]]
+* Panksepp, J. (1998). ''Affective Neuroscience: The Foundations of Human and Animal Emotions''. Oxford University Press.
-[[Category:Microbiology]]
+* LeDoux, J. (1996). ''The Emotional Brain: The Mysterious Underpinnings of Emotional Life''. Simon & Schuster.
-{{stub}}
+[[Category:Neuroscience]]
+[[Category:Evolutionary biology]]