bioRxiv Science⌕ Search

Biology subjects

Marcus, A.

Publications and source records attributed to Marcus, A..

2 recordsLinked to original sources

The Environmental Games

For over 4 billion years, the environment has guided evolutionary selection by presenting biological entities with opportunities and challenges and by mediating their interactions. In evolutionary game theory (EGT), the replicator equation defines the game according to direct interactions between biological entities. Eco-evolutionary models have described environmental feedback by modeling environmental states dynamically. Yet, these models channel environmental pressures through the direct interaction coefficients instead of creating a distinct game. Here, I invent Pure Environmental Games (PEGs) and formally introduce the environment as a strategy in EGT. The PEGs describe the neutral selection game and environmental games operating in parallel. Through the net specific accumulation rates of microbes parametrized by the environmental state, Environmental Biotechnology--an engineering discipline designing wastewater treatment plants worldwide -- offers a collection of instances of PEGs. The environmental strategy resists invasion from biological strategies when it is a strict Nash equilibrium. The PEGs provide a template for identifying regimes of environmental selection within an environmental game (e.g., the r/K selection game). This mapping identifies persistence as a new dynamic regime under extinction. In a closed system, life persists by partnering with the environmental strategy consistent with Schrodingers negative entropy.

evolutionary biology↗

Sodium Butyrate Rescues Neurodevelopmental Deficits Following Perinatal Methadone Exposure

Prenatal opioid exposure (POE) induces long-term neurodevelopmental, behavioral and cognitive deficits for which no targeted treatments are available. The mechanisms underlying POE deficits are poorly understood, but have been linked to a range of central, peripheral, and enteric nervous system changes. Emerging evidence indicates that maternal microbiota changes may also contribute to these long-term deficits in offspring. Here we test the efficacy of the short-chain fatty acid sodium butyrate (NaB) to mitigate POE-induced deficits in a rat model. Both methadone and sodium butyrate treatments altered dam microbiota composition and function: notably methadone disrupted dam gene expression of microbial enzymes critical for butyric acid production and reduced faecal butyric acid levels. In postnatal day 9 pups, methadone increased gut barrier permeability that was reversed with NaB, and enzymatic disruptions were observed in pups at postnatal day 21 that resolved in adulthood. POE induced anxiety-like behavior in adolescence, and adult deficits in working spatial memory and attentional processing that were partially rescued in rats that had received prenatal NaB. POE was associated with decreased myelination in the hippocampus, and this was partially reversed by NaB. Together these results highlight for the first time the link between the gut-brain axis in animal models of POE. Furthermore, they provide the first indication in a rat model of NaB as a simple yet effective treatment to significantly improve the outcomes of children born with POE.

animal behavior and cognition↗