Biology subjects

Uchigashima, M.

Publications and source records attributed to Uchigashima, M..

3 recordsLinked to original sources

bioRxiv2020

A Specific Neuroligin3-αNeurexin1 Code Regulates GABAergic Synaptic Function in Mouse Hippocampus

Synapse formation and regulation require interactions between pre- and postsynaptic proteins, notably cell adhesion molecules (CAMs). It has been proposed that the functions of neuroligins (Nlgns), postsynaptic CAMs, rely on the formation of trans-synaptic complexes with neurexins (Nrxns), presynaptic CAMs. Nlgn3 is a unique Nlgn isoform that localizes at both excitatory and inhibitory synapses. However, Nlgn3 function mediated via Nrxn interactions is unknown. Here, we demonstrate that Nlgn3 localizes at postsynaptic sites apposing vesicular glutamate transporter 3-expressing (VGT3+) inhibitory terminals and regulates VGT3+ inhibitory interneuron-mediated synaptic transmission in mouse organotypic slice cultures. Gene expression analysis of interneurons revealed that the Nrxn1+AS4 splice isoform is highly expressed in VGT3+ interneurons as compared with other interneurons. Most importantly, postsynaptic Nlgn3 requires presynaptic Nrxn1+AS4 expressed in VGT3+ interneurons to regulate inhibitory synaptic transmission. Our results indicate that specific Nlgn-Nrxn interactions generate distinct functional properties at synapses.

neuroscience↗

bioRxiv2020

Neuroligin3 Splice Isoforms Shape Mouse Hippocampal Inhibitory Synaptic Function

Synapse formation is a dynamic process essential for neuronal circuit development and maturation. At the synaptic cleft, trans-synaptic protein-protein interactions constitute major biological determinants of proper synapse efficacy. The balance of excitatory and inhibitory synaptic transmission (E-I balance) stabilizes synaptic activity. Dysregulation of the E-I balance has been implicated in neurodevelopmental disorders including autism spectrum disorders. However, the molecular mechanisms underlying E-I balance remain to be elucidated. Here, we investigate Neuroligin (Nlgn) genes that encode a family of postsynaptic adhesion molecules known to shape excitatory and inhibitory synaptic function. We demonstrate that Nlgn3 protein differentially regulates inhibitory synaptic transmission in a splice isoform-dependent manner at hippocampal CA1 synapses. Distinct subcellular localization patterns of Nlgn3 isoforms contribute to the functional differences observed among splice variants. Finally, single-cell sequencing analysis reveals that Nlgn1 and Nlgn3 are the major Nlgn genes and that expression of Nlgn splice isoforms are highly diverse in CA1 pyramidal neurons.

neuroscience↗

bioRxiv2019

Enhanced emotional memory retrieval by chemogenetic activation of locus coeruleus norepinephrine neurons

The ability to retrieve memory store in response to the environment is essential for animal behavioral adaptation. Norepinephrine (NE)-containing neurons in the brain play a key role in the modulation of synaptic plasticity underlying various processes of memory formation. However, the role of the central NE system in memory retrieval remains unclear. In this study, we developed a neural chemogenetic activation strategy using insect olfactory Ionotropic Receptors (IRs), and used it for selective stimulation of NE neurons in the locus coeruleus (LC) in transgenic mice. Ligand-induced activation of LC NE neurons resulted in enhancement of the retrieval process of conditioned taste aversion, which was mediated through at least partly adrenergic receptors in the amygdala. Pharmacological blockade of LC activity confirmed the facilitative role of these neurons in memory retrieval. Our findings indicate that the LC-amygdalar pathway is required and sufficient for enhancing the recall of taste associative memory.

neuroscience↗