Biology subjects

Paulson, A. L.

Publications and source records attributed to Paulson, A. L..

3 recordsLinked to original sources

bioRxiv2025

Molecular and biological characterization of a distinct species of Lolavirus infecting different accessions of seashore paspalum, a turfgrass, widely grown in the United States

Seashore paspalum (Paspalum sp.), is an economically significant grass used in golf courses, sports fields, and landscaping in the United States. A novel Lolavirus, tentatively named paspalum latent virus (PaLV), was identified for the first time in seashore paspalum plants from the USDA National Plant Germplasm System (NPGS) using high-throughput sequencing. Three complete genome sequences of PaLV from different Paspalum accessions, with a length of 6,995 nucleotides (nt), not including the poly(A) tail, were obtained by Rapid Amplification of cDNA Ends and Sanger sequencing. Phylogenetic analysis based on the replicase protein sequences from the Alphaflexiviridae family revealed that PaLV grouped with the Lolavirus genus, with the closest relative being Lolium latent virus (LoLV). PaLV shares less than 72% nt identity to the replicase and coat protein genes of LoLV, which demarks PaLV as a new species and the second member of the genus. Furthermore, the coat protein region showed intense negative selection pressure and low spatially structured diversity. Host range analysis of PaLV showed that wheat, corn, sorghum, and Lolium are systemic hosts of PaLV. A one-step RT-PCR technique was developed to reliably detect PaLV infection.

pathology↗

bioRxiv2024

40 Hz sensory stimulation enhances CA3-CA1 coordination and prospective coding during navigation in a mouse model of Alzheimer's disease

40 Hz sensory stimulation ("flicker") has emerged as a new technique to potentially mitigate pathology and improve cognition in mouse models of Alzheimers disease (AD) pathology. However, it remains unknown how 40 Hz flicker affects neural codes essential for memory. Accordingly, we investigate the effects of 40 Hz flicker on neural representations of experience in the hippocampus of the 5XFAD mouse model of AD by recording 1000s of neurons during a goal-directed spatial navigation task. We find that an hour of daily exposure to 40 Hz audio-visual stimulation over 8 days leads to higher coordination between hippocampal subregions CA3 and CA1 during navigation. Consistent with CA3s role in generating sequential activity that represents future positions, 40 Hz flicker exposure increased prospective coding of future positions. In turn, prospective coding was more prominent during efficient navigation behavior. Our findings show how 40 Hz flicker enhances key hippocampal activity during behavior that is important for memory. Significance StatementBrain stimulation has emerged as a new potential therapeutic approach to potentially correct or improve altered neural activity in Alzheimers disease. One such approach, 40 Hz sensory stimulation, or flicker, has been shown to improve cognition in disease models. However, it is not clear how 40 Hz flicker affects neural activity underlying memory processes. Here, we investigate how 40 Hz flicker exposure affects neural activity patterns that are crucial for memory. We find 40Hz flicker increases neural coordination in memory circuits, indicating better communication. Furthermore, 40Hz flicker increased neural representations of future positions, patterns theorized to support memory-based planning. These results indicate that 40 Hz flicker increases key neural activity that is important for memory.

neuroscience↗

bioRxiv2024

Body size interacts with the structure of the central nervous system: A multi-center in vivo neuroimaging study

Clinical research emphasizes the implementation of rigorous and reproducible study designs that rely on between-group matching or controlling for sources of biological variation such as subjects sex and age. However, corrections for body size (i.e. height and weight) are mostly lacking in clinical neuroimaging designs. This study investigates the importance of body size parameters in their relationship with spinal cord (SC) and brain magnetic resonance imaging (MRI) metrics. Data were derived from a cosmopolitan population of 267 healthy human adults (age 30.1{+/-}6.6 years old, 125 females). We show that body height correlated strongly or moderately with brain gray matter (GM) volume, cortical GM volume, total cerebellar volume, brainstem volume, and cross-sectional area (CSA) of cervical SC white matter (CSA-WM; 0.44[≤]r[≤]0.62). In comparison, age correlated weakly with cortical GM volume, precentral GM volume, and cortical thickness (-0.21[≥]r[≥]-0.27). Body weight correlated weakly with magnetization transfer ratio in the SC WM, dorsal columns, and lateral corticospinal tracts (-0.20[≥]r[≥]-0.23). Body weight further correlated weakly with the mean diffusivity derived from diffusion tensor imaging (DTI) in SC WM (r=-0.20) and dorsal columns (-0.21), but only in males. CSA-WM correlated strongly or moderately with brain volumes (0.39[≤]r[≤]0.64), and weakly with precentral gyrus thickness and DTI-based fractional anisotropy in SC dorsal columns and SC lateral corticospinal tracts (-0.22[≥]r[≥]-0.25). Linear mixture of sex and age explained 26{+/-}10% of data variance in brain volumetry and SC CSA. The amount of explained variance increased at 33{+/-}11% when body height was added into the mixture model. Age itself explained only 2{+/-}2% of such variance. In conclusion, body size is a significant biological variable. Along with sex and age, body size should therefore be included as a mandatory variable in the design of clinical neuroimaging studies examining SC and brain structure.

neuroscience↗