bioRxiv Science⌕ Search

Biology subjects

Xu, X. Z. S.

Publications and source records attributed to Xu, X. Z. S..

3 recordsLinked to original sources

Automated analysis of C. elegans behavior by LabGym: an open-source, AI-powered platform

The genetic tractability, well-mapped circuitry, and diverse behavioral repertoire of the nematode C. elegans make it an ideal model for physiological and behavioral studies. A wide range of methods has been developed for analyzing C. elegans behaviors, evolving with advances in technology such as videography and computer-assisted analysis. Here, we introduce LabGym--an open-source, artificial intelligence (AI)-based platform we recently developed--to the C. elegans research community. We trained deep learning models in LabGym capable of automatically categorizing and quantifying multiple user-defined parameters of worm locomotion behavior in multi-worm videos with high accuracy. Furthermore, we demonstrated their efficacy in quantifying locomotion changes in aging worms. Our work offers a cost-effective, user-accessible approach to behavioral analysis in C. elegans.

animal behavior and cognition↗

A Spinal Circuit That Transmits Innocuous Cool Sensations

Temperature information is precisely processed in the nervous system. While progress has been made in identifying molecular thermosensors in the periphery, the neural circuits that process temperature information in the central nervous system remain unknown. Here we have identified an essential node in the neural circuitry for innocuous cool sensations. We found that a population of excitatory interneurons co-expressing Calbindin1 and Lbx1 (Calb1Lbx1) in the dorsal horn of the spinal cord is activated by innocuous cool temperatures. Genetic ablation or silencing of spinal Calb1Lbx1 neurons causes loss of innocuous cool but not noxious cold sensations. Further Brainbow labeling with expansion microscopy and electrophysiology showed that a small cluster of spinal Calb1Lbx1 interneurons in lamina I and the outer layer of lamina II represents the cooling-transmission neurons. These neurons receive monosynaptic connections from TRPM8+ primary sensory neurons and amplify the activity of cool-sensitive spinoparabrachial projection neurons. Our findings reveal a microcircuit in the dorsal spinal cord that specifically transmits innocuous cool sensations.

neuroscience↗

A conserved nuclear export complex coordinates transcripts for dopaminergic synaptogenesis and neuronal surviva

Synaptic vesicle and active zone proteins are required for synaptogenesis. The molecular mechanisms for coordinated synthesis of these proteins are not understood. Using forward genetic screens, we identified the conserved THO nuclear export Complex (THOC) as master regulator of presynapse development in C.elegans dopaminergic neurons. In THOC mutants, synaptic messenger RNAs are trapped in the nucleus, resulting in dramatic decrease of synaptic protein expression, near complete loss of synapses and compromised dopamine function. cAMP-responsive element binding protein (CREB) interacts with THOC to mark activity-dependent transcripts for efficient nuclear export. Deletion of the THOC subunit Thoc5 in mouse dopaminergic neurons causes severe defects in synapse maintenance and subsequent neuronal death in the Substantia Nigra compacta (SNc). These cellular defects lead to abrogated dopamine release, ataxia and animal death. Together, our results argue that nuclear export mechanisms can select specific mRNAs and be a rate-limiting step for synapse development and neuronal survival.\n\nHighlightsO_LIDopaminergic presynapses are severely impaired in thoc mutant worms and mice\nC_LIO_LITHOC specifically controls the nuclear export of synaptic transcripts\nC_LIO_LICREB recruits THOC onto activity-dependent synaptic transcripts for efficient export\nC_LIO_LIDopamine neurons in the SNc degenerate upon conditional knock-out of thoc5\nC_LI

neuroscience↗