Biology subjects

Lyon, K. A.

Publications and source records attributed to Lyon, K. A..

2 recordsLinked to original sources

bioRxiv2025

Astrocyte SEMA3C reduction improves Rett Syndrome phenotypes

Astrocytes support neuronal function during development through secreted proteins, yet how astrocyte-secreted cues are altered in disease states and contribute to neurodevelopmental disorders remains poorly defined. Rett syndrome (RTT) is a regressive neurodevelopmental disorder characterized by motor, sensory, and cognitive impairments. Here, we identify the class 3 semaphorin SEMA3C as an astrocyte-secreted protein that contributes to RTT pathology. We show that Sema3c expression is elevated in astrocytes in vivo in RTT model mice and find that SEMA3C is sufficient to inhibit cortical neuron dendrite outgrowth. Normalization of astrocyte SEMA3C levels in female RTT model mice rescues dendritic arborization deficits, restores synaptic activity, and improves visual acuity and motor behavior. Mechanistically, both SEMA3C and RTT astrocyte conditioned media inhibit dendrite outgrowth through PLXND1-dependent signaling. Together, these findings identify astrocyte-secreted SEMA3C as a contributor to RTT pathology and highlight SEMA3C and PLXND1 signaling as potential therapeutic targets in neurodevelopmental disorders.

neuroscience↗

bioRxiv2020

A single-cell transcriptomic and anatomic atlas of mouse dorsal raphe Pet1 neurons

Among the brainstem raphe nuclei, the dorsal raphe nucleus (DR) contains the greatest number of Pet1-lineage neurons, a predominantly serotonergic group distributed throughout DR subdomains. These neurons collectively regulate diverse physiology and behavior and are often therapeutically targeted to treat affective disorders. Characterizing Pet1 neuron molecular heterogeneity and relating it to anatomy is vital for understanding DR functional organization, with potential to inform therapeutic separability. Here we use high-throughput and DR subdomain-targeted single-cell transcriptomics and intersectional genetic tools to map molecular and anatomical diversity of DR-Pet1 neurons. We describe up to fourteen neuron subtypes, many showing biased cell body distributions across the DR. We further show that P2ry1-Pet1 DR neurons - the most molecularly distinct subtype - possess unique efferent projections and electrophysiological properties. These data complement and extend previous DR characterizations, combining intersectional genetics with multiple transcriptomic modalities to achieve fine-scale molecular and anatomic identification of Pet1 neuron subtypes.

neuroscience↗