parahippokampaln

The parahippocampal gyrus is a C-shaped cortical area in the human brain located medial to the temporal lobe. It surrounds the hippocampus and is a crucial component of the limbic system, playing a significant role in memory formation and retrieval, particularly in the consolidation of short-term memory into long-term memory. The parahippocampal gyrus is also involved in spatial navigation and processing sensory information.

Neuroanatomically, the parahippocampal gyrus is situated on the medial surface of the temporal lobe, inferior to the collateral sulcus and superior to the hippocampal sulcus. It is an integral part of the hippocampal formation, which also includes the hippocampus proper, dentate gyrus, and subiculum. This complex is densely interconnected with various brain regions, including the amygdala, prefrontal cortex, and thalamus, enabling its widespread influence on cognitive functions.

Functionally, the parahippocampal gyrus is essential for declarative memory, which encompasses both episodic memory (memories of specific events) and semantic memory (general knowledge). It acts as a relay station, receiving input from association cortices and projecting to the hippocampus for memory encoding. Damage to the parahippocampal gyrus can lead to severe anterograde amnesia, the inability to form new memories, as well as deficits in spatial memory and recognition. Research suggests that alterations in parahippocampal function are implicated in various neurological and psychiatric conditions, including Alzheimer's disease, epilepsy, and schizophrenia.