hippocampus

Examples of hippocampus in the following topics:

• Neural Correlates of Memory Consolidation

  • The hippocampus, amygdala, and cerebellum play important roles in the consolidation and manipulation of memory.
  • Consolidation occurs through communication between several parts of the brain, including the hippocampus, the amygdala, and the cerebellum.
  • The hippocampus is critical to the formation of memories of events and facts.
  • All this contributes to the idea that the hippocampus may not be crucial in memory retention in the post-consolidation stages.
  • The hippocampus is integral in consolidating memories from short-term to long-term memory.

• The Limbic System

  • There are several important structures within the limbic system: the amygdala, hippocampus, thalamus, hypothalamus, basal ganglia, and cingulate gyrus.
  • Due to its close proximity to the hippocampus, the amygdala is involved in the modulation of memory consolidation, particularly emotionally-laden memories.
  • The hippocampus is found deep in the temporal lobe, and is shaped like a seahorse.
  • Some researchers consider the hippocampus to be responsible for general declarative memory (memories that can be explicitly verbalized, such as memory of facts and episodic memory).
  • This image shows the horned hippocampus deep within the temporal lobe.

• Limbic System

  • It includes the hippocampus, amygdala, anterior thalamic nuclei, septum, limbic cortex, and fornix, and supports a variety of functions including emotion, behavior, motivation, long-term memory, and olfaction.
  • Hippocampus: Required for the formation of long-term memories and implicated in maintenance of cognitive maps for navigation.
  • Fornix: A white matter structure that carries signals from the hippocampus to the mammillary bodies and septal nuclei.
  • The septal nuclei receive reciprocal connections from the olfactory bulb, hippocampus, amygdala, hypothalamus, midbrain, habenula, cingulate gyrus, and thalamus.

• Amnesia

  • Amnesia, the inability to recall certain memories, often results from damage to any of a number of regions in the temporal lobe and hippocampus.
  • Amnesia typically occurs when there is damage to a variety of regions of the temporal lobe or the hippocampus, causing the inability to recall memories before, or after, an (often traumatic) event.
  • Retrograde amnesia is usually caused by head trauma or brain damage to parts of the brain other than the hippocampus (which is involved with the encoding process of new memories).
  • Brain regions related to this condition include the medial temporal lobe, medial diencephalon, and hippocampus.
  • The virus damaged his hippocampus, the area of the brain required in the transfer of memories from short-term to long-term storage.

• Amnesia

  • H.M. developed pronounced anterograde amnesia after his hippocampus and amygdala were removed to treat severe epilepsy.
  • Both categories of amnesia can occur together in the same patient, and commonly result from drug effects or damage to the brain regions most closely associated with episodic memory: the medial temporal lobes and especially the hippocampus.
  • This form of amnesia is distinct in that abnormalities in the hippocampus can sometimes be visualized using a special form of magnetic resonance imaging of the brain known as diffusion-weighted imaging (DWI).

• Biology of Emotion

  • Its structures include the hypothalamus, thalamus, amygdala, and hippocampus.
  • The hippocampus integrates emotional experience with cognition.
  • The hippocampus is also involved in emotional processing.
  • Individuals suffering from posttraumatic stress disorder (PTSD) show marked reductions in volume in several parts of the hippocampus, which may be the result of decreased levels of neurogenesis and dendritic branching (the generation of new neurons and the generation of new dendrites in existing neurons, respectively) (Wang et al., 2010).
  • Its structures include the hypothalamus, thalamus, amygdala, and hippocampus

• Defining Emotion

  • The limbic system includes the amygdala and the hippocampus and functions as the brain’s emotional circuit.
  • Both the amygdala and the hippocampus play a role in normal emotional processing as well as in mood and anxiety disorders.

• Neural Correlates of Memory Storage

  • The hippocampus is essential for the consolidation of information from short-term to long-term memory; however, it does not seem to store information itself, adding mystery to the question of where memories are stored.
  • The hippocampus receives input from different parts of the cortex and sends output to various areas of the brain.
  • The hippocampus may be involved in changing neural connections for at least three months after information is initially processed.

• Brain: Cerebral Cortex and Brain Lobes

  • It also contains the hippocampus (Greek for "seahorse", which is what it resembles), a structure that processes memory formation.
  • The role of the hippocampus in memory was partially determined by studying one famous epileptic patient, HM, who had both sides of his hippocampus removed in an attempt to cure his epilepsy.

• Stress and Disease

  • The regions of the brain involved in memory processing that are implicated in PTSD include the hippocampus, amygdala, and frontal cortex, while the heightened stress response is likely to involve the thalamus, hypothalamus, and locus coeruleus.
  • This atrophy of the hippocampus is thought to represent decreased neuronal density.
  • However, long-term exposure to cortisol damages cells in the hippocampus, which results in impaired learning.