Definition

1. Noun:
   • A seahorse: A small marine fish of the genus Hippocampus, characterized by a horse-like head, a prehensile tail, and bony plates covering its body.
   • A neural structure: A complex, curved structure within the brain, located in the medial temporal lobe and resembling a seahorse in shape. It is a major component of the limbic system and is critically involved in the formation of new memories, learning, and spatial navigation.

Usage

• Noun (Marine Biology):
  • The hippocampus is a unique fish that swims upright.
  • We observed a hippocampus clinging to seaweed with its tail.
• Noun (Neuroanatomy):
  • Damage to the hippocampus can result in severe memory impairment.
  • The hippocampus is essential for converting short-term memories into long-term ones.

Advanced Usage

• "Hippocampal" (Adjective): Pertaining to the hippocampus in the brain.
  • The study focused on hippocampal activity during sleep.
• "Hippocampal formation": A broader term in neuroscience that includes the hippocampus proper along with related structures like the dentate gyrus and subiculum.
  • The hippocampal formation is a key site for neurogenesis in adults.

Variants and Related Words

• Hippocampi: The plural form of hippocampus, used in both biological and anatomical contexts.
  • The fossil record shows various species of ancient hippocampi.
  • The hippocampi in both brain hemispheres work together.

Synonyms

• Seahorse: The common name for the marine fish .
• (Brain structure): There is no direct single-word synonym, but it is a part of the limbic system and is sometimes described as the "memory center."

Related Phrases

• Hippocampus-dependent memory: Memories that require the hippocampus for their formation, such as declarative (fact-based) and episodic (event-based) memories.
  • Spatial navigation tasks often rely on hippocampus-dependent memory.
• Hippocampal atrophy: The wasting away or loss of neurons in the hippocampus, often associated with conditions like Alzheimer's disease.
  • MRI scans revealed significant hippocampal atrophy in the patient.

Related Idioms

There are no common idioms that directly feature the word "hippocampus." Its usage is primarily scientific and academic.

Noun

1. seahorses
2. a complex neural structure (shaped like a sea horse) consisting of grey matter and located on the floor of each lateral ventricle; intimately involved in motivation and emotion as part of the limbic system; has a central role in the formation of memories