Biology subjects

Goodell, B.

Publications and source records attributed to Goodell, B..

4 recordsLinked to original sources

bioRxiv2025

Aseptic, semi-sealed cranial chamber implants for chronic multi-channel neurochemical and electrophysiological neural recording in nonhuman primates

We developed an implantable neural interface for monitoring both chemical and electrical forms of brain activity in monkeys that maintains aseptic properties for year-long periods while leveraging the modular functions (e.g., sensor moveability) provided by a chamber system. Invasive electrophysiological recordings, especially in subcortical structures from nonhuman primates usually involves implanting electrodes into the brain through a skull-mounted chamber. These electrodes may be attached temporarily for several hours of recording, or permanently. Permanent attachments are favorable to allow for sealing the chamber completely from externally originating pathogenic species that can infiltrate and compromise the health of the animal. A sealed chamber also reduces the need for frequent chamber cleaning required to minimize the accumulation of pathogenic organisms. However, neurochemical measurements require specialized electrodes with extremely fragile carbon fiber tips and are not compatible with recently developed sealed chamber systems. Here, we leveraged osseointegrating materials and hermetic sealing strategies to enable both neurochemical and electrical neural activity measurements from a sealed chamber with an aspirating port for culturing chamber fluid to ensure an aseptic environment. The system was shown to provide successful recordings of neural activity in two monkeys while maintaining negative bacteria culture results for over a year post-implant.

neuroscience↗

bioRxiv2024

Volumetric mesoscopic electrophysiology: a new imaging modality for the non-human primate

The primate brain is a densely interconnected organ whose function is best understood by recording from the entire structure in parallel, rather than parts of it in sequence. However, available methods either have limited temporal resolution (functional magnetic resonance imaging), limited spatial resolution (macroscopic electroencephalography), or a limited field of view (microscopic electrophysiology). To address this need, we developed a volumetric, mesoscopic recording approach (MePhys) by tessellating the volume of a monkey hemisphere with 992 electrode contacts that were distributed across 62 chronically implanted multi-electrode shafts. We showcase the scientific promise of MePhys by describing the functional interactions of local field potentials between the more than 300,000 simultaneously recorded pairs of electrodes. We find that a subanesthetic dose of ketamine -believed to mimic certain aspects of psychosis- can create a pronounced state of functional disconnection and prevent the formation of stable large-scale intrinsic states. We conclude that MePhys provides a new and fundamentally distinct window into brain function whose unique profile of strengths and weaknesses complements existing approaches in synergistic ways.

neuroscience↗

bioRxiv2021

Impact of Norway spruce pre-degradation stages induced by G. trabeum on fungal and bacterial communities

In forests ecosystems, fungi and bacteria are key actors in wood degradation. However, few studies have focused on the impact of fungal pre-degradationon bacterial and fungal communities. Coniferous forests are dominated by Brown rot fungi that are involved in earliest phase of lignocellulose breakdown, and therefore, influencing the second phase of microbial colonization. This study aimed to investigate the first microbial species colonizing after intermediate and advanced pre-degradation by the brown rot fungus Gloeophyllum trabeum. Using Illumina metabarcoding, bacterial and fungal communities were monitored after 70 days from Picea abies wood blocks placed between forest floor and topsoil. Chemical composition of the wood samples was determined for each of the pre-degradation stages. We observed significant changes in the bacterial and fungal communities associated with the pre-degradation of P. abies, and that wood substrate condition acted as a gatekeeper for both microbial communities. Our data also suggested that fungal and bacterial communities could interact and act in a synergistic way during the wood decomposition process.

microbiology↗

bioRxiv2021

The Role of Low Molecular Weight Fungal Metabolites in Grapevine Trunk Disease Pathogenesis: Eutypa Dieback and Esca

Eutypa dieback and Esca are serious grapevine trunk diseases (GTDs) caused by fungal consortia causing large economic losses in vineyards. Depending on the disease the species involved include Eutypa lata, Phaeoacremonium minimum, and Phaeomoniella chlamydospora. There is a need to understand the complex pathogenesis mechanisms used by these causative fungi to develop treatments for the diseases they cause. Low molecular weight metabolites (LMW) are known to be involved in non-enzymatic oxygen radical generation in fungal degradation of wood by some Basidiomycota species, and as part of our work to explore the basis for fungal consortia pathogenesis, LMW metabolite involvement by the causal GTD fungi was explored. The GTD fungal pathogens examined, Eutypa lata, Phaeoacremonium minimum and Phaeomoniella chlamydospora, were found to produce low molecular weight iron binding metabolites that preferentially reduced iron or redox cycled to produce hydrogen peroxide. Uniquely, different LMW metabolites isolated from the GTD fungi promoted distinct chemistries that are important in a type of non-enzymatic catalysis known as chelator-mediated Fenton (CMF) reactions. CMF chemistry promoted by LMW metabolites from these fungi allowed for the generation of highly reactive hydroxyl radicals under conditions promoted by the fungi. We hypothesize that this new reported mechanism may help to explain the necrosis of woody grapevine tissue as a causal mechanism important in pathogenesis in these two grapevine trunk diseases. IMPORTANCEUnderstanding the pathogenesis of grape trunk diseases (GTDs) is the key to the development of disease control and treatment. While fungal extracellular enzyme systems are typically cited relative to their fungal mechanisms in pathogenesis, non-enzymatic mechanisms have been less studied in this regard and the role of low molecular weight (LMW) fungal metabolites in GTD development is quite limited. In this article, we demonstrate that GTD-causative fungal pathogens Eutypa lata, Phaeoacremonium minimum and Phaeomoniella chlamydospore produce LMW phenolic metabolites under iron-restricted conditions. These metabolites undergo a series of redox reactions, with different fungi producing metabolites that preferentially either reduce iron, or generate hydrogen peroxide, under conditions simulating grapevine woody tissue. These conditions have the potential to promote generation of highly damaging hydroxyl radicals through a mechanism that appears to be similar to non-enzymatic chelator-mediated Fenton (CMF) chemistry which is involved in fungal degradation of wood by non-related fungal orders. This is the first report of CMF chemistry promoted by GTD-causative fungi under laboratory conditions and the research suggests an alternate pathway that may contribute to pathogenesis in GTDs, and a potential target for vine protection.

microbiology↗