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Brain: Limbic system
The limbic system within the brain.
NeuroNamesancil-247
Dorlands/Elsevier s_33/12787580
The limbic system is the part of the human brain involved in emotion, motivation, and emotional association with memory. It influences the formation of memory by integrating emotional states with stored memories of physical sensations. (See emotional memory). The term "limbic" comes from Latin limbus, meaning "border" or "edge".

Anatomy

The limbic system includes many structures in the cerebral cortex and sub-cortex of the brain. Different books list different sets of structures. For ease of interpretation, this is a list of all the regions generally considered to be part of the limbic system:

Function

The limbic system operates by influencing the endocrine system and the autonomic nervous system. It is highly interconnected with the nucleus accumbens, the brain's pleasure center, which plays a role in sexual arousal and the "high" derived from certain recreational drugs. These responses are heavily modulated by dopaminergic projections from the limbic system. In 1954, Olds and Milner found that rats with metal electrodes implanted into their nucleus accumbens repeatedly pressed a lever activating this region, and did so in preference to eating and drinking, eventually dying of exhaustion.[1]

The limbic system is also tightly connected to the prefrontal cortex. Some scientists contend that this connection is related to the pleasure obtained from solving problems. To cure severe emotional disorders, this connection was sometimes surgically severed, a procedure of psychosurgery, called a prefrontal lobotomy (this is actually a misnomer). Patients who underwent this procedure often became passive and lacked all motivation.

There is circumstantial evidence that the limbic system also provides a custodial function for the maintenance of a healthy conscious state of mind.

Evolution

The limbic system is embryologically older than other parts of the brain. It developed to manage 'fight' or 'flight' chemicals and is an evolutionary necessity for reptiles as well as humans.

Recent studies of the limbic system of tetrapods have challenged some long-held tenets of forebrain evolution. The common ancestors of reptiles and mammals had a well-developed limbic system in which the basic subdivisions and connections of the amygdalar nuclei were established.[2]

History

The French physician Paul Broca first called this part of the brain "le grand lobe limbique" in 1878,[3] but most of its putative role in emotion was developed only in 1937 when the American physician James Papez described his anatomical model of emotion, the Papez circuit.[4] Paul D. MacLean expanded these ideas to include additional structures in a more dispersed "limbic system," more on the lines of the system described above.[5] The concept of the limbic system has since been further expanded and developed by Nauta, Heimer and others.

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Human brain - Limbic system
Amygdala • Cingulate gyrus • Fornicate gyrus • Hippocampus • Hypothalamus • Mammillary body • Nucleus accumbens • Olfactory System •Orbitofrontal cortex • Parahippocampal gyrus


References

1. ^ Olds, J., Milner, P. 1954. Positive reinforcement produced by electrical stimulation of septal area and other regions of rat brain. J.Comp. Physiolo. Psycholo. 47, 419- 427
2. ^ Bruce LL, Neary TJ (1995). "The limbic system of tetrapods: a comparative analysis of cortical and amygdalar populations". Brain Behav. Evol. 46 (4-5): 224-34. PMID 8564465. 
3. ^ Broca, P. Anatomie comparée des circonvolutions cérébrales: le grand lobe limbique. Rev. Anthropol. 1878;1:385-498.
4. ^ Papez JW. A proposed mechanism of emotion. 1937. J Neuropsychiatry Clin Neurosci. 1995;7(1):103-12. PMID 7711480
5. ^ Maclean, PD. Some psychiatric implications of physiological studies on frontotemporal portion of limbic system (visceral brain). Electroencephalogr Clin Neurophysiol 1952;4(4):407-18. PMID 12998590
In animals, the brain or encephalon (Greek for "in the skull"), is the control center of the central nervous system, responsible for behavior. The brain is located in the head, protected by the skull and close to the primary sensory apparatus of vision, hearing,
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NeuroNames is a system of nomenclature for the human and/or macaque brain.

It is maintained by the University of Washington and is a part of a tool called "BrainInfo". BrainInfo helps one identify structures in the brain.
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Elsevier, the world's largest publisher of medical and scientific literature, forms part of the Reed Elsevier group. Based in Amsterdam, the company has substantial operations in the UK, USA and elsewhere.
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The human brain controls the central nervous system (CNS), by way of the cranial nerves and spinal cord, the peripheral nervous system (PNS) and regulates virtually all human activity.
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emotion is a "complex reaction pattern, involving experiential, behavioral, and physiological elements, by which the individual attempts to deal with a personally significant matter of event.
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In psychology, memory is an organism's ability to store, retain, and subsequently retrieve information. Traditional studies of memory began in the realms of philosophy, including techniques of artificially enhancing the memory.
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only after a delay. For instance, Kleinsmith and Kaplan (1963) [24] found an advantage for numbers paired with arousing words over those paired with neutral words only at delayed test, but not at immediate test.
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Latin}}} 
Official status
Official language of: Vatican City
Used for official purposes, but not spoken in everyday speech
Regulated by: Opus Fundatum Latinitas
Roman Catholic Church
Language codes
ISO 639-1: la
ISO 639-2: lat
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cerebral cortex is a structure within the vertebrate brain with distinct structural and functional properties. In non-living, preserved brains, the outermost layers of the cerebrum has a grey color, hence the name "grey matter".
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In animals, the brain or encephalon (Greek for "in the skull"), is the control center of the central nervous system, responsible for behavior. The brain is located in the head, protected by the skull and close to the primary sensory apparatus of vision, hearing,
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amygdalae (Latin, also corpus amygdaloideum, singular amygdala, from Greek
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The hippocampus is a part of the forebrain, located in the medial temporal lobe. It forms a part of the limbic system and plays a part in memory and spatial navigation. Humans and other mammals have two hippocampi, one in each side of the brain.
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Long-term memory (LTM) is memory, stored as meaning, that can last as little as 30 seconds or as long as decades. It differs structurally and functionally from working memory or short-term memory, which ostensibly stores items for only around 30 seconds.
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The parahippocampal gyrus (or hippocampal gyrus) is a grey matter cortical region of the brain that surrounds the hippocampus. This region plays an important role in memory encoding and retrieval.
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The hippocampus is a part of the forebrain, located in the medial temporal lobe. It forms a part of the limbic system and plays a part in memory and spatial navigation. Humans and other mammals have two hippocampi, one in each side of the brain.
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Cingulate gyrus (lat. belt ridge) is a gyrus in the medial part of the brain. It partially wraps around the corpus callosum and is limited above by the cingulate sulcus.

The cortical part of the cingulate gyrus is referred to as cingulate cortex.
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Heart rate is a term used to describe the frequency of the cardiac cycle. It is considered one of the four vital signs. Usually it is calculated as the number of contractions (heart beats) of the heart in one minute and expressed as "beats per minute" (bpm).
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Blood pressure (strictly speaking: vascular pressure) refers to the force exerted by circulating blood on the walls of blood vessels, and constitutes one of the principal vital signs.
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Attention is the cognitive process of selectively concentrating on one aspect of the environment while ignoring other things. Examples include listening carefully to what someone is saying while ignoring other conversations in the room (the cocktail party effect) or listening to a
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fornicate gyrus is a gyrus of the cerebral cortex, located on the medial surface adjacent to the corpus callosum. It is named for the fornix, a tract of white matter that runs beneath its surface roughly in a loop, from the amygdala to the mamillary bodies.
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The hypothalamus links the nervous system to the endocrine system via the pituitary gland (hypophysis). The hypothalamus, (from Greek ὑποθαλαμος = under the thalamus) is located below the thalamus, just above the brain stem.
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hormone (from Greek όρμή - "to set in motion") is a chemical messenger that carries a signal from one cell (or group of cells) to another. All multicellular organisms produce hormones (including plants - see phytohormone).
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Hunger is a feeling experienced when the glycogen level of the liver falls below a threshold, usually followed by a desire to eat. The usually unpleasant feeling originates in the hypothalamus and is released through receptors in the liver.
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Drinking is the act of consuming a liquid through the mouth. Water, for example, is required for many of life's physiological processes, and excess or decreased water intake is associated with health problems.
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Sexual arousal is the process and state of an animal being ready for sexual activity and feeling an urge for sexual contact.

Human sexual arousal

Unlike most animals, human beings of both sexes are potentially capable of sexual arousal throughout the year, therefore, there
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A circadian rhythm is a roughly-24-hour cycle in the physiological processes of living beings, including plants, animals, fungi and cyanobacteria. The term "circadian", coined by Franz Halberg,[1] comes from the Latin circa, "around", and diem or
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The mammillary bodies are a pair of small round bodies, located on the undersurface of the brain, that form part of the limbic system. They are located at the ends of the anterior arches of the fornix, and are named mammillary for their resemblance to two breasts.
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The nucleus accumbens (NAcc), also known as the accumbens nucleus or as the nucleus accumbens septi (Latin for nucleus leaning against the septum), is a collection of neurons within the forebrain, located where the head of the caudate and the anterior
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42 (1), 43-55. doi: 10.1111/1468-5906.t01-1-00160
18. ^ Moreira-Almeida Alexander, Lotufo Neto Francisco, Koenig Harold G. "Religiousness and mental health: a review" . Rev. Bras. Psiquiatr. [serial on the Internet]. 2006 September, cited 2007 June 21, 2007 ; 28(3): 242-250.
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An addiction is a recurring compulsion by an individual to engage in some specific activity, despite harmful consequences to the individuals health, mental state or social life.
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