entorhinális

Entorhinal cortex, or entorhinális kéreg in Hungarian, is a region of the medial temporal lobe that serves as a major hub between the neocortex and the hippocampal formation. It sits in the parahippocampal gyrus, just anterior to the hippocampus, and is a central component of the limbic system involved in memory, navigation, and contextual processing.

The entorhinal cortex is traditionally divided into two subregions: the medial entorhinal cortex (MEC) and the lateral entorhinal cortex (LEC). It contains six cortical layers; the superficial layers II and III project to the hippocampus via the perforant pathway, while the deeper layers V and VI receive output from the hippocampus and relay information back to cortical networks. MEC is particularly associated with spatial representations, including grid and directional signals, whereas LEC is more involved with object-related and contextual information.

Functions of the entorhinal cortex center on its role as a gateway for multimodal sensory information entering the hippocampus, supporting the formation and consolidation of episodic memories and relational associations. Its connections with hippocampal subfields, including the dentate gyrus, CA3, and CA1, enable a bidirectional hippocampal–cortical loop that underpins navigation, scene construction, and memory organization. The discovery of grid cells in the MEC has been pivotal for understanding neural coding of space.

Clinical relevance includes its early involvement in neurodegenerative diseases; the entorhinal cortex is one of the first regions to show atrophy and tau pathology in Alzheimer's disease, with degeneration correlating with memory impairment. Damage or dysfunction in this area can disrupt episodic memory formation and spatial navigation, underscoring its critical role in memory networks.