Hippocampus: Difference between revisions

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{{Short description|A critical structure in the brain involved in memory and navigation}}
{{short description|Part of the brain involved in memory and navigation}}
{{Use dmy dates|date=October 2023}}


The '''hippocampus''' is a major component of the brains of humans and other vertebrates. It belongs to the [[limbic system]] and plays important roles in the consolidation of information from short-term memory to long-term memory, and in spatial memory that enables navigation.
==Hippocampus==
The '''hippocampus''' is a major component of the [[brain]] of humans and other [[vertebrates]]. It belongs to the [[limbic system]] and plays important roles in the consolidation of information from [[short-term memory]] to [[long-term memory]], and in [[spatial memory]] that enables navigation.
 
[[File:Gray739-emphasizing-hippocampus.png|thumb|right|Diagram of the human brain with the hippocampus highlighted.]]


==Anatomy==
==Anatomy==
The hippocampus is located in the medial temporal lobe of the brain, underneath the cortical surface. It has a distinctive curved shape that has been likened to a seahorse, which is reflected in its name derived from the Greek words "hippos" (horse) and "kampos" (sea monster).
The hippocampus is located in the [[medial temporal lobe]] of the brain, underneath the cortical surface. It has a distinctive curved shape that has been likened to a [[seahorse]], which is reflected in its name derived from the Greek words "hippos" (horse) and "kampos" (sea monster).


===Structure===
[[File:Hippocampus_and_seahorse_cropped.JPG|thumb|left|The hippocampus is named for its resemblance to a seahorse.]]
The hippocampus consists of two main interlocking parts:
* The [[Cornu Ammonis]] (CA) regions, which are divided into CA1, CA2, CA3, and CA4.
* The [[dentate gyrus]], which is involved in the formation of new episodic memories.


The hippocampus is connected to other parts of the brain via the [[entorhinal cortex]], which serves as a major input and output relay.
The hippocampus consists of two main interlocking parts: the [[Ammon's horn]] and the [[dentate gyrus]]. The Ammon's horn is further divided into subfields CA1, CA2, CA3, and CA4, each with distinct cellular compositions and functions.


==Function==
==Function==
The hippocampus is crucial for the formation of new memories and is also associated with learning and emotions. It is particularly important for spatial memory and navigation, allowing organisms to remember locations and navigate through their environment.
The primary function of the hippocampus is in the formation of new memories and is also associated with learning and emotions. It is particularly important for [[declarative memory]], which involves facts and events, and [[spatial memory]], which involves the ability to navigate and remember locations.


===Memory Formation===
[[File:Blausen_0614_LimbicSystem.png|thumb|right|The hippocampus is part of the limbic system, shown here in a diagram of the human brain.]]
The hippocampus is involved in the consolidation of information from short-term memory to long-term memory. It is particularly important for the formation of declarative memories, which are memories that can be consciously recalled, such as facts and events.
 
===Memory===
The hippocampus is crucial for the formation of new memories. Damage to the hippocampus can result in [[anterograde amnesia]], where the ability to form new memories is impaired, while older memories remain intact.


===Spatial Navigation===
===Spatial Navigation===
The hippocampus contains place cells, which are neurons that become active when an animal is in a specific location in its environment. This spatial coding is thought to be a key component of the brain's ability to navigate and understand spatial relationships.
The hippocampus is involved in spatial navigation and memory. It helps in the formation of [[cognitive maps]], which are mental representations of physical locations.
 
[[File:Rats_and_cognitive_maps_and_maze.png|thumb|left|Rats use their hippocampus to navigate mazes, forming cognitive maps.]]
 
==Pathology==
Damage to the hippocampus can result from various conditions, including [[Alzheimer's disease]], [[hypoxia]], [[encephalitis]], or [[temporal lobe epilepsy]]. Such damage can lead to memory deficits and difficulties in spatial navigation.


==Clinical Significance==
==Research==
Damage to the hippocampus can result in severe memory impairments. Conditions such as [[Alzheimer's disease]], [[epilepsy]], and [[hypoxia]] can affect the hippocampus, leading to memory loss and disorientation.
Research on the hippocampus has been extensive, with studies ranging from its role in memory and learning to its involvement in [[neurogenesis]] and [[plasticity]]. The hippocampus is one of the few regions of the brain where new neurons are generated throughout life.


===Alzheimer's Disease===
[[File:Sobo_1909_639.png|thumb|right|Early anatomical drawing of the hippocampus.]]
In Alzheimer's disease, the hippocampus is one of the first regions of the brain to suffer damage. This leads to the characteristic memory loss and disorientation seen in the disease.


===Epilepsy===
==Comparative Anatomy==
The hippocampus is often involved in temporal lobe epilepsy, where seizures originate in or affect this region of the brain.
The structure and function of the hippocampus are conserved across many species, including [[mammals]], [[birds]], and [[reptiles]]. In [[macaques]], the hippocampus is similarly involved in memory and spatial navigation.


==Research==
[[File:Brainmaps-macaque-hippocampus.jpg|thumb|left|Hippocampus in a macaque brain.]]
Research on the hippocampus has provided significant insights into how memories are formed and stored. Studies using techniques such as [[functional magnetic resonance imaging]] (fMRI) and [[electrophysiology]] have advanced our understanding of hippocampal function.
 
==Historical Perspective==
The study of the hippocampus has a rich history, with significant contributions from scientists such as [[Santiago Ramón y Cajal]], who provided detailed drawings of its structure.
 
[[File:CajalHippocampus_(modified).png|thumb|right|Drawing of the hippocampus by Santiago Ramón y Cajal.]]
 
==Neuroanatomy==
The hippocampus is part of the [[archicortex]], one of the oldest parts of the brain in evolutionary terms. It is connected to other parts of the brain through the [[fornix]] and receives input from the [[entorhinal cortex]].


==Images==
[[File:Hippocampus_coronal_section176157.fig.004.jpg|thumb|left|Coronal section of the hippocampus.]]
[[File:Hippocampus.png|thumb|right|Diagram of the hippocampus showing its location in the brain.]]
[[File:Hippocampus_structure.png|thumb|left|Detailed structure of the hippocampus, highlighting the CA regions and dentate gyrus.]]


==Related pages==
==Related pages==
* [[Limbic system]]
* [[Limbic system]]
* [[Memory]]
* [[Memory]]
* [[Neuroscience]]
* [[Spatial memory]]
* [[Temporal lobe]]
* [[Neurogenesis]]
* [[Cognitive map]]


[[Category:Neuroscience]]
[[Category:Brain]]
[[Category:Memory]]
[[Category:Memory]]
[[Category:Brain]]
[[Category:Limbic system]]

Latest revision as of 14:15, 21 February 2025

Part of the brain involved in memory and navigation



Hippocampus[edit]

The hippocampus is a major component of the brain of humans and other vertebrates. It belongs to the limbic system and plays important roles in the consolidation of information from short-term memory to long-term memory, and in spatial memory that enables navigation.

Diagram of the human brain with the hippocampus highlighted.

Anatomy[edit]

The hippocampus is located in the medial temporal lobe of the brain, underneath the cortical surface. It has a distinctive curved shape that has been likened to a seahorse, which is reflected in its name derived from the Greek words "hippos" (horse) and "kampos" (sea monster).

The hippocampus is named for its resemblance to a seahorse.

The hippocampus consists of two main interlocking parts: the Ammon's horn and the dentate gyrus. The Ammon's horn is further divided into subfields CA1, CA2, CA3, and CA4, each with distinct cellular compositions and functions.

Function[edit]

The primary function of the hippocampus is in the formation of new memories and is also associated with learning and emotions. It is particularly important for declarative memory, which involves facts and events, and spatial memory, which involves the ability to navigate and remember locations.

The hippocampus is part of the limbic system, shown here in a diagram of the human brain.

Memory[edit]

The hippocampus is crucial for the formation of new memories. Damage to the hippocampus can result in anterograde amnesia, where the ability to form new memories is impaired, while older memories remain intact.

Spatial Navigation[edit]

The hippocampus is involved in spatial navigation and memory. It helps in the formation of cognitive maps, which are mental representations of physical locations.

Rats use their hippocampus to navigate mazes, forming cognitive maps.

Pathology[edit]

Damage to the hippocampus can result from various conditions, including Alzheimer's disease, hypoxia, encephalitis, or temporal lobe epilepsy. Such damage can lead to memory deficits and difficulties in spatial navigation.

Research[edit]

Research on the hippocampus has been extensive, with studies ranging from its role in memory and learning to its involvement in neurogenesis and plasticity. The hippocampus is one of the few regions of the brain where new neurons are generated throughout life.

Early anatomical drawing of the hippocampus.

Comparative Anatomy[edit]

The structure and function of the hippocampus are conserved across many species, including mammals, birds, and reptiles. In macaques, the hippocampus is similarly involved in memory and spatial navigation.

Hippocampus in a macaque brain.

Historical Perspective[edit]

The study of the hippocampus has a rich history, with significant contributions from scientists such as Santiago Ramón y Cajal, who provided detailed drawings of its structure.

Drawing of the hippocampus by Santiago Ramón y Cajal.

Neuroanatomy[edit]

The hippocampus is part of the archicortex, one of the oldest parts of the brain in evolutionary terms. It is connected to other parts of the brain through the fornix and receives input from the entorhinal cortex.

Coronal section of the hippocampus.

Related pages[edit]