PT  - JOURNAL ARTICLE
AU  - Peter H. Chipman
AU  - Alejandra Pazo Fernandez
AU  - Chi Chung Alan Fung
AU  - Angelo Tedoldi
AU  - Atsushi Kawai
AU  - Sunita Ghimire Gautam
AU  - Mizuki Kurosawa
AU  - Manabu Abe
AU  - Kenji Sakimura
AU  - Tomoki Fukai
AU  - Yukiko Goda
TI  - Astrocyte GluN2C NMDA receptors control basal synaptic strengths of hippocampal CA1 pyramidal neurons in the <em>stratum radiatum</em>
AID  - 10.1101/2021.05.28.446253
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.05.28.446253
4099  - http://biorxiv.org/content/early/2021/06/10/2021.05.28.446253.short
4100  - http://biorxiv.org/content/early/2021/06/10/2021.05.28.446253.full
AB  - Experience-dependent plasticity is a key feature of brain synapses for which neuronal N-Methyl-D-Aspartate receptors (NMDARs) play a major role, from developmental circuit refinement to learning and memory. Astrocytes also express NMDARs although their exact function has remained controversial. Here we identify a circuit function for GluN2C NMDAR, a subtype highly expressed in astrocytes, in layer-specific tuning of synaptic strengths in mouse hippocampal CA1 pyramidal neurons. Interfering with astrocyte NMDAR or GluN2C NMDAR activity reduces the range of presynaptic strength distribution specifically in the stratum radiatum inputs without an appreciable change in the mean presynaptic strength. Mathematical modeling shows that narrowing of the width of presynaptic release probability distribution compromises the expression of long-term synaptic plasticity. Our findings suggest a novel feedback signaling system that uses astrocyte GluN2C NMDARs to adjust basal synaptic weight distribution of Schaffer collateral inputs, which in turn impacts computations performed by the CA1 pyramidal neuron.Competing Interest StatementThe authors have declared no competing interest.