Biology subjects

Brown, A. M.

Publications and source records attributed to Brown, A. M..

At least 19 recordsLinked to original sources

bioRxiv2026

Age-Adjusted Cerebellar Volumetry and Developmental Outcomes in Extremely Low Birth Weight Infants

Background: Infants with extremely low birth weight (ELBW) are at high risk for neurodevelopmental impairment, but the relationship between cerebellar structure and later developmental outcome remains incompletely defined. Methods: In this retrospective single-center study, we examined total cerebellar volume on clinically acquired brain magnetic resonance imaging (MRI) in ELBW infants while accounting for postmenstrual age (PMA) at imaging. Results: Of 65 infants screened, 42 were included. Mean gestational age at birth was 25.54 {+/-} 1.68 weeks, mean birth weight was 733.2 {+/-} 118.7 g, and mean PMA at MRI was 43.02 {+/-} 6.53 weeks (range, 31.57--68.00). Mean cerebellar volume was 22.17 {+/-} 9.63 cm. Independently adjudicated developmental outcomes comprised normal development in 16 infants, isolated or specific impairment in 12, and moderate/severe impairment in 14. Unadjusted cerebellar volumes did not differ across developmental groups (P = 0.490) or qualitative MRI categories (P = 0.875). However, the PMA-by-developmental-category interaction was significant (P = 0.002), with estimated cross-sectional slopes of 1.72, 1.56, and 0.39 cm per week, respectively. The interaction remained significant within 36--46 weeks PMA (n = 29; P = 0.011) and after adjustment for small-for-gestational-age (SGA) status. Sensitivity analyses indicated uncertainty in the stability of the interaction. Conclusions: These findings suggest that age-informed cerebellar volumetric patterns may provide developmental information not evident from average volumes alone and support prospective validation with standardized imaging and developmental assessments. As a result, cerebellar volumes obtained early in life may hold prognostic information for ELBW infants.

neuroscience↗

bioRxiv2026

Pick your poison: Tetrodotoxin variants give Pacific newts a potential leg up in the coevolutionary arms race with resistant garter snake predators

Coevolution proceeds through the evolution of traits that mediate ecological interactions and evolutionary outcomes. In the arms race between toxic Pacific newts (Taricha) and their garter snake predators (Thamnophis), this interface involves tetrodotoxin (TTX), an antipredator defense that inhibits nerve and muscle function by blocking voltage-gated sodium channels. In response, snakes have evolved TTX-resistant channels, in some cases leading to snake populations that are nearly invulnerable to TTX. For decades, newt TTX has been treated as a single defensive trait, yet TTX occurs as a family of structurally related analogs that may represent alternative defenses against snakes. Here, we characterize TTX analog diversity in all four species of Taricha and evaluate how these compounds interact with sodium channels in coevolved garter snakes. Using LC-MS analysis of newt skin secretions, we detected a diverse suite of TTX analogs previously unrecognized in Pacific newts. We then used molecular docking models to evaluate interactions between various TTX analogs and variants of the skeletal muscle channel (NaV1.4) that span the range of TTX resistance in garter snakes. We found that some TTX analogs docked better than canonical TTX in resistant snake channels. Notably, we show that 11-deoxy-4-epi-TTX and 11-deoxy-TTX have favorable interactions with hydrophobic amino-acid substitutions in extremely resistant garter snake sodium channels, potentially circumventing predator resistance to canonical TTX. Our results suggest a complex arms race involving multiple newt TTX analogs and multiple snake sodium channel variants. As such, newts may keep pace with snakes by diversifying their arsenal of chemical weapons. SignificanceIn western North America, some newts have enough toxin in their skin to kill most predators, but coevolution has led to toxin resistance in their garter snake predators that in some cases is so extreme that snakes should be able to withstand more toxin than newts could possibly possess. Here, we explore the possibility that newts may be able to fight back against these resistant predators through the by evolving a diverse repertoire of toxins. We use chemical analyses and computational modeling to show that newts have a wide variety of toxins, some of which are likely to be more effective against resistant snakes, suggesting that coevolution may continue to occur even when snakes become very resistant.

evolutionary biology↗

bioRxiv2026

Development of semisynthetic blasticidin S analogs with potent and fast-killing anti-malarial activity

Protein synthesis represents an attractive target space for the development of anti-malarials with novel modes of action. Natural-product inhibitors of the eukaryotic 80S ribosome can have potent anti-malarial activity but are often poorly selective due to mammalian cytotoxicity. Blasticidin S (BlaS) is a microbially-produced natural product that broadly inhibits prokaryotic and eukaryotic protein synthesis by binding to the ribosomal peptidyl transferase center. In this study, we explored the potential for improving the anti-malarial potency and selectivity of the blasticidin S scaffold with semi-synthetic analogs that are modified at the C6 and C4 sites. The two best analogs were two orders of magnitude more potent than BlaS against Plasmodium falciparum drug-sensitive and -resistant lines while displaying low cytotoxicity towards mammalian cells. These analogs exhibited improved kinetics of inhibition of protein synthesis in cultured parasites and blocked the development of asexual stages expressing the plasmodial surface anion channel, a transporter required for nutrient acquisition and BlaS uptake. They also exhibited a dramatically improved speed of killing over BlaS. Molecular docking analysis revealed that these analogs are able to form more interactions with the P. falciparum ribosomal peptidyl transferase center than is BlaS, which is consistent with their increased potency. Together, these studies demonstrate the feasibility of generating BlaS analogs with potent anti-malarial activity and provide a roadmap for further development.

microbiology↗

bioRxiv2026

Metaplastic sleep regulation in Drosophila determined by microscale circadian neural dynamics

The biophysical mechanisms by which circadian clock neurons integrate temporal coding signals to regulate sleep remain elusive. Here, using Drosophila, we identify Rabphilin (Rph) in DN1p clock neurons as a key stabilizer of the metaplasticity setpoint governing circadian regulation of sleep. Rph protein levels are elevated at night relative to daytime and modulate stochastic process of DN1p membrane potential dynamics linked to variability in synaptic activity at connections between DN1p neurons and their downstream postsynaptic partners. We find that Rph acts as a bidirectional regulator of synaptic plasticity thresholds. Under dim nocturnal light stimulation, Rph knockdown permits synaptic potentiation, whereas synthesized Rph introduction induces synaptic depression. In contrast, under optogenetic manipulation mimicking daytime spiking in DN1p neurons, these effects are reversed. We further show that spike-timing-dependent plasticity emerges when postsynaptic spiking is engaged, with nocturnal dim light conditions determining the direction of plasticity. Together, these findings establish a mechanistic link between microscale circadian neural dynamics and hierarchical metaplastic regulation, demonstrating how circadian regulation of sleep dynamically balances stability and adaptive flexibility through circadian setpoints and environmental nocturnal light interactions. Significance StatementWe show that circadian metaplasticity regulates sleep through membrane potential dynamics. Circadian clock neurons implement flexible metaplasticity, whereby the direction can be determined by internal circadian setpoints and interactions with nocturnal environmental light. This mechanism engages spike-timing-dependent plasticity to determine plasticity polarity. Our findings identify membrane potential dynamics as a computational substrate for physiological state control, linking molecular mechanisms to circuit-level circadian regulation of sleep. Together, they reframe sleep regulation as an active metaplastic process that hierarchically integrates microscale circadian neural dynamics to optimize circuit function.

neuroscience↗

bioRxiv2025

Drude SILCS-Nucleic: Harnessing Explicit Electronic Polarization in Targeting RNA and DNA for Drug Design

The growing interest in nucleic acids as therapeutic targets has prompted the devel-opment of novel computational methods to facilitate drug discovery. In this study, we extend the Site Identification by Ligand Competitive Saturation (SILCS) methodology to characterize ligand-nucleic acid interactions using the Drude polarizable force field. We demonstrate the ability of the Drude force field to better model solute-nucleic acid interactions, resulting in improved identification of known binding sites and ligand binding favorability predictions across a diverse set of nucleic acid structures. This new workflow addresses limitations in previous SILCS studies by exploiting the en-hanced sampling of solutes in the original SILCS-RNA workflow, accurately modeling the interactions of charged species, and improving solute sampling in minor groove binding sites. These results establish this Drude-based SILCS workflow as a valuable tool for structure-based drug design targeting nucleic acids and offer insights into solute preferences that can guide rational ligand design.

biophysics↗

bioRxiv2025

PlantCV v4: Image analysis software for high-throughput plant phenotyping

PlantCV is an open-source Python project aimed at developing tools to address a range of image-based, plant phenotyping questions. PlantCV has been used for more than 10 years to automate trait collection from image data and the newest release, PlantCV version 4, continues to lower the barrier to entry for users without substantial coding experience through extensive example use-case tutorials and simplified installation. In addition to usability, we document added functionality since the release of PlantCV v2, including support for more image types such as fluorescence, thermal, and hyperspectral data. Finally, we describe the development of a new subpackage focused on morphological trait measurements like leaf angle, and demonstrate its utility as compared to more manual methods of data collection. CORE IDEASO_LIPlantCV is an open-source, open-development, Python-based software package that has a new release for improved functionality and usability to make image analysis flexible and easier for researchers without a coding background. C_LIO_LIPlantCV is now capable of handling new data types that are relevant to researchers, such as thermal and hyperspectral, and has built in functionality for extracting information from these image types. C_LIO_LIThe software project aims to lower the barrier to entry into image analysis for researchers by providing numerous, versioned, interactive tutorials that cover most common use cases, particularly in plant science. C_LI

plant biology↗

bioRxiv2025

Chronic alcohol intake elicits distinct multi-omic profiles in the liver versus skeletal muscle of mice

Alcohol-related liver disease and alcohol-related myopathy are widespread consequences of chronic alcohol use. However, understanding of the associated molecular mechanisms and effective treatments remains limited. To address this, we employed multi-omics to uncover molecular blueprints of liver versus skeletal muscle responses to chronic alcohol exposure, using a pre-clinical mouse model showing signs of alcohol-related liver dysregulation (diminished liver phosphatidylcholine-to-phosphatidylethanolamine lipid ratio) and alcohol-related myopathy (reduced muscle mass and strength). We found that the liver was more sensitive to chronic alcohol than muscle across the transcriptome, proteome and metabolome levels, but both tissues were equally sensitive at the lipidome level. The liver displayed an extensive and multi-layered metabolic molecular profile, while muscle was associated with upregulated inflammatory and matrisome responses and impaired mitochondrial energetics. Lipidome analyses also revealed a novel potential role for altered phospholipid remodelling in the aetiology of alcohol-related myopathy. Finally, computational drug repurposing identified several compounds for therapeutic targeting of alcohol-induced liver (e.g., saracatinib, GSK126) and muscle (e.g., metformin, trichostatin A) pathophysiology, perhaps working partly to counter metabolic dysregulation. Overall, our study provides a tractable list of therapeutic targets and treatments to help expedite the understanding of and countermeasures against alcohol-related liver disease and alcohol-related myopathy in humans.

bioinformatics↗

bioRxiv2025

FUNCTIONAL ANALYSIS OF BIPARTITE NRF2 ACTIVATORS THAT OVERCOME FEEDBACK REGULATION FOR AGE-RELATED CHRONIC DISEASES

Activating Nrf2 with small molecules is a promising strategy for countering aging, oxidative stress, inflammation, and various disorders, including neurodegeneration. The primary regulator of Nrf2 protein stability is Keap1, a redox sensor protein and an adapter in the Cullin III ubiquitin ligase complex, which labels Nrf2 for proteasomal degradation. The known Nrf2 activators either chemically modify sensor thiols in Keap1 or competitively displace Nrf2 from the ubiquitin ligase complex. The latter approach is considered the most suitable for continuous administration, as non-specific chemical modifiers of Keap1 thiols also modify active thiols on other proteins, thus causing side effects. However, when transitioning from homogeneous to cell-based assays, genuine displacement activators show a significant loss in potency by several orders of magnitude. As we demonstrate here, this offset is due to the presence of high micromolar concentrations of Keap1 in both the cell lines and brain tissue. A potential solution could involve targeted delivery of an alkylating agent to Keap1 to achieve the desired specificity. Transcriptomic analysis of a cell-permeable Nrf2 peptide bearing an alkylating fumarate moiety indicates selective activation of the Nrf2 genetic program, confirming the high specificity of this approach. The Nrf2-triggered genetic program has a feedback regulation mechanism through the activation of Bach1, an Nrf2 transcriptional repressor, which is elevated in age-related neurodegeneration. Thus, a benign bipartite Nrf2 activator with Bach1 inhibition properties is needed for maximal benefits. The recently developed heterocyclic carboxamide, HPPE, shows overlap with the Nrf2 pathway activated by the fumarate-linked Nrf2 peptide and with zinc and tin protoporphyrins, which are recognized inhibitors of Bach1. Therefore, HPPE presents a promising and unique combination of the two desired activities that could be further optimized to treat age-related neurodegeneration. HighlightsO_LIThe decrease in potency for reversible displacement activators of Nrf2 in biological assays is attributed to high micromolar concentrations of Keap1 and competition with endogenous Keap1 client proteins. C_LIO_LINrf2 activators specific for Keap1 should combine a displacement scaffold with a substitution that undergoes intracellular conversion into active pro-oxidant or alkylating species. C_LIO_LICell-permeable fumarate-linked Nrf2 peptide solely activates the Nrf2 antioxidant genetic program, as demonstrated by transcriptomic analysis. C_LIO_LIHPPE, a small bipartite molecule, exhibits properties of both Nrf2 activation and Bach1 inhibition, to bypass feedback regulation by targeting both Keap1 and Bach1. C_LI

biochemistry↗

bioRxiv2024

Type IV pili-associated secretion of a biofilm matrix protein from Clostridium perfringens that forms intermolecular isopeptide bonds

Clostridium perfringens is a Gram-positive, anaerobic, spore-forming, bacterial pathogen of humans and animals. C. perfringens also produces type IV pili (T4P) and has two complete sets of T4P-associated genes, one of which has been shown to produce surface pili needed for cell adherence. One hypothesis about the second set of T4P genes is that they comprise a system analogous to the type II secretion systems (TTSS) found in Gram-negative bacteria, which is used to export folded proteins from the periplasm through the outer membrane to the extracellular environment. Gram-positive bacteria have a similar secretion barrier in the thick peptidoglycan (PG) layer, which blocks secretion of folded proteins >25 kD. To determine if the T4P-associated genes comprise a Gram-positive TTSS, the secretome of mutants lacking type IV pilins were examined and a single protein, a von Willebrand A domain containing protein, BsaC (CPE0517), was identified as being dependent on pilin PilA3 for secretion. The bsaC gene is in an operon with genes encoding a SipW signal peptidase and two putative biofilm matrix proteins BsaA and BsaB, both of which have remote homology to Bacillus subtilis biofilm protein TasA. Since BsaA forms long oligomers that are secreted, we analyzed BsaA monomer interactions with de novo modeling. These models projected that the monomers formed isopeptide bonds as part of a donor strand exchange process, in which an N-terminal disordered loop of one monomer intercalates into a beta sheet structure of an adjacent monomer and reforms into a beta sheet with subsequent isopeptide bond formation. Mutations in residues predicted to form the isopeptide bonds led to loss of oligomerization, supporting an exchange and lock mechanism. Phylogenetic analysis showed the BsaA family of proteins are widespread among bacteria and archaea but only a subset is predicted to form isopeptide bonds. ImportanceFor bacteria to secrete folded proteins to the environment, they have to overcome the physical barriers of an outer membrane in Gram-negative bacteria and the thick peptidoglycan layer in Gram-positive bacteria. One mechanism to do this is the use of a Type II secretion system in Gram-negative bacteria, which has a structure similar to type IV pili and is modeled to act as a piston that pumps folded proteins through the outer membrane to the environment. Clostridium perfringens, like all or most all of the clostridia, has type IV pili and, in fact, has two sets of pilus-associated genes. Here we present evidence that C. perfringens uses one set of pilus genes to secrete a biofilm associated protein and may be responsible for secreting the main biofilm protein, BsaA. We show that BsaA monomers are, unlike most other biofilm matrix proteins, linked by intermolecular isopeptide bonds, enhancing the physical strength of BsaA fibers.

microbiology↗

bioRxiv2024

Protein-ligand co-design: a case for improving binding affinity between Type II NADH:quinone oxidoreductase and quinones

Biological engineering aims to enhance biological systems by designing proteins with improved catalytic properties or ligands with enhanced function. Typically, applications permit designing proteins, e.g., an enzyme in a biodegradation reaction, or ligands e.g., a drug for a target receptor, but not both. Yet, some applications can benefit from a more flexible approach where both the protein and ligand can be designed or modified together to enhance a desired property. To meet the need for this co-design capability, we introduce a novel co-design paradigm and demon- strate its application to Ndh2-quinone pairings to enhance their binding affinity. Ndh2, type-II NADH dehydrogenase, is an enzyme found in certain bacteria that facilities extracellular electron transfer (EET) when interacting with exogenous quinone mediators. This interaction leads to the generation of a detectable electric current that can be used for biosensing applications. Our results demonstrate the benefits of the co-design paradigm in realizing Ndh2-quinone pairings with enhanced binding affinities, therefore highlighting the importance of considering protein-ligand engineering from a holistic co-design perspective.

bioinformatics↗

bioRxiv2024

A myelinic channel system for organelle transport to the glial-axonal junction

Myelin sheaths comprise compacted layers of oligodendroglial membrane wrapped spirally around axons. Each sheath, if imagined unwrapped, has a cytoplasm-filled space at its perimeter, linking it to the oligodendrocyte soma via a short process. By electron microscopy (EM), this space, which we term the myelinic channel system contains microtubules and membranous organelles, but whether these are remnants of development or serve a function is unknown. Performing live imaging of myelinating oligodendrocytes expressing fluorescent reporters, we found that the myelinic channel system serves microtubule-dependent organelle transport. Further, the intra-myelinic movement of peroxisomes was modulated by neuronal electrical activity in these mixed neural cell cultures. Loss of oligodendroglial Kif21b or CNP in vivo led to apparent stasis of myelin organelles and secondary axon pathology. This suggests that oligodendrocytes require motor transport in myelin to maintain axonal integrity.

neuroscience↗

bioRxiv2024

Targeting DBS to the centrolateral thalamic nucleus improves movement in a lesion-based model of acquired cerebellar dystonia in mice

Dystonia is the third most common movement disorder and an incapacitating co-morbidity in a variety of neurologic conditions. Dystonia can be caused by genetic, degenerative, idiopathic, and acquired etiologies, which are hypothesized to converge on a "dystonia network" consisting of the basal ganglia, thalamus, cerebellum, and cerebral cortex. In acquired dystonia, focal lesions to subcortical areas in the network - the basal ganglia, thalamus, and cerebellum - lead to a dystonia that can be difficult to manage with canonical treatments, including deep brain stimulation (DBS). While studies in animal models have begun to parse the contribution of individual nodes in the dystonia network, how acquired injury to the cerebellar outflow tracts instigates dystonia; and how network modulation interacts with symptom latency remain as unexplored questions. Here, we present an electrolytic lesioning paradigm that bilaterally targets the cerebellar outflow tracts. We found that lesioning these tracts, at the junction of the superior cerebellar peduncles and the medial and intermediate cerebellar nuclei, resulted in acute, severe dystonia. We observed that dystonia is reduced with one hour of DBS of the centrolateral thalamic nucleus, a first order node in the network downstream of the cerebellar nuclei. In contrast, one hour of stimulation at a second order node in the short latency, disynaptic projection from the cerebellar nuclei, the striatum, did not modulate the dystonia in the short-term. Our study introduces a robust paradigm for inducing acute, severe dystonia, and demonstrates that targeted modulation based on network principles powerfully rescues motor behavior. These data inspire the identification of therapeutic targets for difficult to manage acquired dystonia.

neuroscience↗

bioRxiv2024

Mechanistic insights into transport models of the sphingolipid transport protein, Spinster homolog 2 (Spns2), using MD simulations

Sphingosine-1-phosphate (S1P) is a sphingolipid signaling molecule that when elevated results in multiple disease states including metastatic cancers. Modulating the extracellular concentrations of S1P has been an evolving strategy in drug development for metastatic cancers due to its role in angiogenesis and cell migration. Research has shown that Spns2, the S1P transport protein, is an important microenvironment regulatory gene in metastatic lung cancer colonization and has demonstrated that Spns2 inhibition is a powerful suppressor of metastatic cancers. Spns2 transports and regulates cellular levels of S1P but has unresolved aspects related to mechanism of transport. Here, molecular modeling strategies including, homology modeling and molecular dynamics (MD) simulations, were used to determine structural mechanisms of action related to S1P transport and exploitable for inhibition. Results indicate Spns2 contains a unique salt-bridge network essential for structural stability that is disrupted by the R119A mutation. Additionally, we observe that Spns2 follows a rocker-switch transport model and that S1P translocation is initialized by interacting with residues such as Thr216, Arg227, and Met230. This work provides initial insight into structural morphologies sampled by Spns2, the role of a complex salt bridge network, and residues engaged in structural state transition that can be targeted with inhibitors to control extracellular concentrations of S1P.

biophysics↗

bioRxiv2024

Site-specific sulfations regulate the physicochemical properties of papillomavirus-heparan sulfate interactions for entry

Certain human papillomaviruses (HPVs) are etiological agents for several anogenital and oropharyngeal cancers. During initial infection, HPV16, the most prevalent cancer-causing type, specifically interacts with heparan sulfates (HS), not only enabling initial cell attachment but also triggering a crucial conformational change in viral capsids termed structural activation. It is unknown, whether such HS-HPV16 interactions depend on HS sulfation patterns. Thus, we probed potential roles of HS sulfations using cell-based functional and physicochemical assays, including single molecule force spectroscopy. Our results demonstrate that N-sulfation of HS is crucial for virus binding and structural activation by providing high affinity sites, and that additional 6O-sulfation is required to mechanically stabilize the interaction, whereas 2O-sulfation and 3O-sulfation are mostly dispensable. Together, our findings identify the contribution of HS sulfation patterns to HPV16 binding and structural activation and reveal how distinct sulfation groups of HS synergize to facilitate HPV16 entry, which, in turn, likely influences the tropism of HPVs. TeaserDistinct heparan sulfations facilitate HPV16 binding and structural activation through their physico-chemical properties.

microbiology↗

bioRxiv2023

Polinton-like Viruses Associated with Entomopoxviruses Provide Insight into Replicon Evolution

Polinton-like viruses (PLVs) are a diverse group of small integrative dsDNA viruses that infect diverse eukaryotic hosts. Many PLVs are hypothesized to parasitize viruses in the phylum Nucleocytoviricota for their own propagation and spread. Here we analyze the genomes of novel PLVs associated with the occlusion bodies of entomopoxvirus (EV) infections of two separate lepidopteran hosts. The presence of these elements within EV occlusion bodies suggests that they are the first known hyperparasites of poxviruses. We find that these PLVs belong to two distinct lineages that are highly diverged from known PLVs. These PLVs possess mosaic genomes, and some essential genes share homology with mobile genes within EVs. Based on this homology and observed PLV mosaicism, we propose a mechanism to explain the turnover of PLV replication and integration genes.

genomics↗

bioRxiv2023

From goal to outcome: analyzing the progression of biomedical sciences PhD careers in a longitudinal study using an expanded taxonomy

Biomedical sciences PhDs pursue a wide range of careers inside and outside academia. However, there is little data regarding how career interests of PhD students relate to the decision to pursue postdoctoral training or to their eventual career outcomes. Here, we present the career goals and career outcomes of 1,452 biomedical sciences PhDs who graduated from Vanderbilt University between 1997-2021. We categorized careers using an expanded three-tiered taxonomy and flags that delineate key career milestones. We also analyzed career goal changes between matriculation and defense, and the reasons why students became more- or less-interested in research-intensive faculty careers. We linked students career goal at defense to whether they did a postdoc, the duration of time between defense and the first non-training position, the career area of the first non-training position, and the career area of the job at ten years after graduation. Finally, we followed individual careers for ten years after graduation to characterize movement between different career areas over time. We found that most students changed their career goal during graduate school, declining numbers of alumni pursued postdoctoral training, many alumni entered first non-training positions in a different career area than their goal at defense, and the career area of the first non-training position was a good indicator of the job that alumni held 10 years after graduation. Our findings emphasize that students need a wide range of career development opportunities and career mentoring during graduate school to prepare them for futures in research and research-related professions.

scientific communication and education↗

bioRxiv2023

Purkinje cell dysfunction causes disrupted sleep in ataxic mice

Purkinje cell dysfunction causes movement disorders such as ataxia, however, recent evidence suggests that Purkinje cell dysfunction may also alter sleep regulation. Here, we used an ataxia mouse model generated by silencing Purkinje cell neurotransmission (L7Cre;Vgatfx/fx) to better understand how cerebellar dysfunction impacts sleep physiology. We focused our analysis on sleep architecture and electrocorticography (ECoG) patterns based on their relevance to extracting physiological measurements during sleep. We found that circadian activity is unaltered in the mutant mice, although their sleep parameters and ECoG patterns are modified. The L7Cre;Vgatfx/fx mutant mice have decreased wakefulness and rapid eye movement (REM) sleep, while non-rapid eye movement (NREM) sleep is increased. The mutant mice have an extended latency to REM sleep, which is also observed in human ataxia patients. Spectral analysis of ECoG signals revealed alterations in the power distribution across different frequency bands defining sleep. Therefore, Purkinje cell dysfunction may influence wakefulness and equilibrium of distinct sleep stages in ataxia. Our findings posit a connection between cerebellar dysfunction and disrupted sleep and underscore the importance of examining cerebellar circuit function in sleep disorders. Summary StatementUtilizing a precise genetic mouse model of ataxia, we provide insights into the cerebellums role in sleep regulation, highlighting its potential as a therapeutic target for motor disorders-related sleep disruptions.

neuroscience↗

bioRxiv2023

Neural spike signatures determine the behavioral presentation of cerebellar disease

The cerebellum contributes to a diverse array of motor conditions including ataxia, dystonia, and tremor. The neural substrates that encode this diversity are unclear. Here, we tested whether the neural spike activity of cerebellar output neurons is distinct between movement disorders with different impairments, generalizable across movement disorders with similar impairments, and capable of causing distinct movement impairments. Using in vivo awake recordings as input data, we trained a supervised classifier model to differentiate the spike parameters between mouse models for ataxia, dystonia, and tremor. The classifier model correctly assigned mouse phenotypes based on single neuron signatures. Spike signatures were shared across etiologically distinct but phenotypically similar disease models. Mimicking these pathophysiological spike signatures with optogenetics induced the predicted motor impairments in otherwise healthy mice. These data show that distinct spike signatures promote the behavioral presentation of cerebellar diseases.

neuroscience↗