Intermediate
Technical
IVT
molecular layer
The superficial layer of cerebral cortex containing few cell bodies but numerous dendrites and synapses.
Full Definition
The molecular layer (Layer I) is the most superficial layer of the cerebral cortex, characterized by a paucity of neuronal cell bodies and an abundance of dendritic processes, axon terminals, and synaptic connections. This layer contains primarily the apical dendrites of pyramidal neurons from deeper layers, along with sparse Cajal-Retzius cells and interneurons. In pathological conditions, the molecular layer may show gliosis, neuronal loss, or specific patterns of protein deposition that aid in diagnostic interpretation.
Usage
Usage note: Specify cortical region when describing pathological changes.
In Context
- "Tau-positive threads were abundant in the molecular layer of the frontal cortex." — Alzheimer's disease case
- "The molecular layer showed preservation of cytoarchitecture despite underlying pathology." — Cortical development study
Also known as
Layer I
plexiform layer
Don't confuse with
granular layer
pyramidal layer