Loss of Grin2a causes a transient delay in the electrophysiological maturation of hippocampal parvalbumin interneurons.
Commun Biol
; 6(1): 952, 2023 09 19.
Article
in En
| MEDLINE
| ID: mdl-37723282
N-methyl-D-aspartate receptors (NMDARs) are ligand-gated ionotropic glutamate receptors that mediate a calcium-permeable component to fast excitatory neurotransmission. NMDARs are heterotetrameric assemblies of two obligate GluN1 subunits (GRIN1) and two GluN2 subunits (GRIN2A-GRIN2D). Sequencing data shows that 43% (297/679) of all currently known NMDAR disease-associated genetic variants are within the GRIN2A gene, which encodes the GluN2A subunit. Here, we show that unlike missense GRIN2A variants, individuals affected with disease-associated null GRIN2A variants demonstrate a transient period of seizure susceptibility that begins during infancy and diminishes near adolescence. We show increased circuit excitability and CA1 pyramidal cell output in juvenile mice of both Grin2a+/- and Grin2a-/- mice. These alterations in somatic spiking are not due to global upregulation of most Grin genes (including Grin2b). Deeper evaluation of the developing CA1 circuit led us to uncover age- and Grin2a gene dosing-dependent transient delays in the electrophysiological maturation programs of parvalbumin (PV) interneurons. We report that Grin2a+/+ mice reach PV cell electrophysiological maturation between the neonatal and juvenile neurodevelopmental timepoints, with Grin2a+/- mice not reaching PV cell electrophysiological maturation until preadolescence, and Grin2a-/- mice not reaching PV cell electrophysiological maturation until adulthood. Overall, these data may represent a molecular mechanism describing the transient nature of seizure susceptibility in disease-associated null GRIN2A patients.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Parvalbumins
/
Calcium
/
Receptors, N-Methyl-D-Aspartate
Type of study:
Etiology_studies
Limits:
Animals
Language:
En
Journal:
Commun Biol
Year:
2023
Document type:
Article
Affiliation country:
Estados Unidos
Country of publication:
Reino Unido