Biology subjects

Goda, Y.

Publications and source records attributed to Goda, Y..

2 recordsLinked to original sources

bioRxiv2021

Astrocyte GluN2C NMDA receptors control basal synaptic strengths of hippocampal CA1 pyramidal neurons in the stratum radiatum

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.

neuroscience↗

bioRxiv2020

Heterosynaptic cross-talk of pre- and postsynaptic strengths along segments of dendrites

Dendrites are crucial for integrating incoming synaptic information. Individual dendritic branches are thought to constitute a signal processing unit, yet how neighbouring synapses shape the boundaries of functional dendritic units are not well understood. Here we addressed the cellular basis underlying the organization of the strengths of neighbouring Schaffer collateral-CA1 synapses by optical quantal analysis and spine size measurements. Inducing potentiation at clusters of spines produced NMDA receptor-dependent heterosynaptic plasticity. The direction of postsynaptic strength change showed distance-dependency to the stimulated synapses where proximal synapses predominantly depressed whereas distal synapses potentiated; potentiation and depression were regulated by CaMKII and calcineurin, respectively. By contrast, heterosynaptic presynaptic plasticity was confined to weakening of presynaptic strength of nearby synapses, which required CaMKII and the retrograde messenger nitric oxide. Our findings highlight the parallel engagement of multiple signalling pathways, each with characteristic spatial dynamics in shaping the local pattern of synaptic strengths.

neuroscience↗