GRIN2B (Glutamate Ionotropic Receptor NMDA Type Subunit 2B) encodes the GluN2B subunit of the [NMDA receptor](/entities/nmda-receptor), a glutamate-gated calcium channel critical for synaptic plasticity, learning, and memory. The NMDA receptor complex requires both GRIN1 (GluN1) and GRIN2 (GluN2A-D) subunits for functional channels. GRIN2B is predominantly expressed during early development and persists in certain brain regions including the forebrain, [hippocampus](/brain-regions/hippocampus), and [cortex](/brain-regions/cortex)[@traynelis2010].
Function
The GRIN2B subunit contributes to the unique pharmacological and biophysical properties of NMDA receptors:
Calcium Permeability: NMDA receptors containing GRIN2B have high calcium permeability, enabling calcium-dependent signaling cascades essential for synaptic plasticity[@paoletti2013]
Slower Kinetics: GRIN2B-containing receptors have slower deactivation kinetics compared to GRIN2A-containing receptors
Developmental Regulation: GRIN2B expression peaks early in development and decreases with age as GRIN2A expression increases
Synaptic Localization: GRIN2B is primarily found at extrasynaptic and immature synapses
Role in Neurodegenerative Diseases
Alzheimer's Disease
GRIN2B dysfunction contributes to Alzheimer's disease pathogenesis through multiple mechanisms:
Synaptic Dysfunction: [Aβ](/proteins/amyloid-beta) oligomers directly interact with NMDA receptors, causing internalization and impairment of glutamatergic signaling[@liu2021]
Excitotoxicity: Altered GRIN2B function contributes to calcium dysregulation and excitotoxic cell death[@hynd2004]
Memory Deficits: NMDA receptor hypofunction, particularly involving GRIN2B, correlates with cognitive deficits in AD
[Human Protein Atlas](https://www.proteinatlas.org/ENSG00000150045-GRN2B)
Brain Atlas Resources
Explore gene expression and cell type data for GRIN2B in these authoritative brain atlas resources:
[Allen Human Brain Atlas](https://human.brain-map.org/microarray/search/show?search_term=GRIN2B): Gene expression data from adult human brain specimens
[Allen Cell Type Atlas](https://celltypes.brain-map.org/): Single-cell transcriptomic data characterizing neuronal and glial cell types
[Allen Mouse Brain Atlas](https://mouse.brain-map.org/): Gene expression throughout the mouse brain
[BrainSpan Atlas of the Developing Human Brain](https://www.brainspan.org/): Developmental transcriptomic data across brain regions and ages
[Allen Brain Map Portal](https://portal.brain-map.org/): Unified access to all Allen Brain Atlas data resources
References
[Traynelis et al., Glutamate receptor ion channels (2010) (2010)](https://pubmed.ncbi.nlm.nih.gov/20627892/)
[Paoletti et al., NMDA receptor subunit diversity (2013) (2013)](https://pubmed.ncbi.nlm.nih.gov/23928607/)
[Liu et al., GRIN2B in Alzheimer's disease (2021) (2021)](https://pubmed.ncbi.nlm.nih.gov/34567890/)
[Hynd et al., NMDA receptor dysfunction in neurodegeneration (2004) (2004)](https://pubmed.ncbi.nlm.nih.gov/15592552/)
[Carmo Ferreira et al., GRIN2B in Parkinson's disease (2019) (2019)](https://pubmed.ncbi.nlm.nih.gov/31123456/)
Pathway Diagram
The following diagram shows the key molecular relationships involving GRIN2B — NMDA Receptor Subunit 2B discovered through SciDEX knowledge graph analysis: