Biology subjects

Barrett, M. E.

Publications and source records attributed to Barrett, M. E..

3 recordsLinked to original sources

bioRxiv2025

Ethics review for insect research in the UK: Patterns, drivers, and perceived impact on research quality and process

Research involving insects currently falls outside the scope of animal welfare legislation in the UK; however, many institutions in the UK require submission of procedures involving insects to their internal ethics review board. Here, we have surveyed UK institutions to assess what proportion require ethics applications for work with insects. Further, we surveyed entomologists working at UK institutions to understand when requirements first came about at their institution and (if applicable) their experiences with ethics review, including feedback received, resources used/desired, and their self-reported confidence in submitting applications. In addition, we assessed entomologists perception of the influence of ethics review on research quality and their general attitudes and values towards the ethical treatment of insects in research and the process of ethics review. Our data demonstrate that just over half of UK institutions (51.6%) require ethics review for research with insects starting in 2008 with a steady trend towards increasing institutional requirements over time. Entomologists currently submitting are largely confident in their applications (68.8%, confident) but the majority believed that resources like training on ethics in the insect context and greater research on insect welfare would be helpful. Entomologists largely believed that ethics applications had either a positive effect (44.6%) or no effect (39.6%) on research quality; early career entomologists were more likely to report a positive effect of ethics review on study quality. Qualitative responses suggest the entomological community has diverse values and attitudes towards the ethical treatment of insects in research.

zoology↗

bioRxiv2023

A long-term ketogenic diet in young and aged rats has dissociable effects on prelimbic cortex and CA3 ensemble activity

Age-related cognitive decline has been linked to distinct patterns of cellular dysfunction in the prelimbic cortex (PL) and the CA3 subregion of the hippocampus. Because higher cognitive functions require both structures, selectively targeting a neurobiological change in one region, at the expense of the other, is not likely to restore normal behavior in older animals. One change with age that both the PL and CA3 share, however, is a reduced ability to utilize glucose, which can produce aberrant neural activity patterns. The current study used a ketogenic diet (KD) intervention, which reduces the brains reliance on glucose, and has been shown to improve cognition, as a metabolic treatment for restoring neural ensemble dynamics in aged rats. Expression of the immediate-early genes Arc and Homer1a were used to quantify the neural ensembles that were active in the home cage prior to behavior, during a working memory/biconditional association task, and a continuous spatial alternation task. Aged rats on the control diet had increased activity in CA3 and less ensemble overlap in PL between different task conditions than did the young animals. In the PL, the KD was associated with increased activation of neurons in the superficial cortical layers. The KD did not lead to any significant changes in CA3 activity. These observations suggest that the KD does not restore neuron activation patterns in aged animals, but rather the availability of ketone bodies in the frontal cortices may permit the engagement of compensatory mechanisms that produce better cognitive outcomes. Significance StatementThis study extends understanding of how a ketogenic diet (KD) intervention may improve cognitive function in older adults. Young and aged rats were given 3 months of a KD or a calorie-match control diet and then expression of the immediate-early genes Arc and Homer1a were measured to examine neural ensemble dynamics during cognitive testing. The KD diet was associated with increased activation of neurons in the superficial layers of the PL, but there were no changes in CA3. These observations are significant because they suggest that compensatory mechanisms for improving cognition are engaged in the presence of elevated ketone bodies. This metabolic shift away from glycolysis can meet the energetic needs of the frontal cortices when glucose utilization is compromised.

neuroscience↗

bioRxiv2020

Age-related alterations in prelimbic cortical neuron Arc expression vary by behavioral state and cortical layer

Prefrontal cortical and medial temporal lobe connectivity is critical for higher cognitive functions that decline in older adults. Likewise, these cortical areas are among the first to show anatomical, functional, and biochemical alterations in advanced age. The prelimbic subregion of the prefrontal cortex and the perirhinal cortex of the medial temporal lobe are densely reciprocally connected and well-characterized as undergoing age-related neurobiological changes that correlate with behavioral impairment. Despite this fact, it remains to be determined how changes within these brain regions manifest as alterations in their functional connectivity. In our previous work, we observed an increased probability of age-related dysfunction for perirhinal cortical neurons that projected to the prefrontal cortex in old rats compared to neurons that were not identified as projection neurons. The current study was designed to investigate the extent to which aged prelimbic cortical neurons also had altered patterns of Arc expression during behavior, and if this was more evident in those cells that had long-range projections to the perirhinal cortex. The expression patterns of the immediate-early gene Arc were quantified in behaviorally characterized rats that also received the retrograde tracer cholera toxin B (CTB) in the perirhinal cortex to identify projection neurons to this region. As in our previous work, the current study found that CTB+ cells were more active than those that did not have the tracer. Moreover, there were age-related reductions in prelimbic cortical neuron Arc expression that correlated with a reduced ability of aged rats to multitask. Unlike the perirhinal cortex, however, the age-related reduction in Arc expression was equally likely in CTB+ and CTB- negative cells. Thus, the selective vulnerability of neurons with long-range projections to dysfunction in old age may be a unique feature of the perirhinal cortex. Together, these observations identify a mechanism involving prelimbic-perirhinal cortical circuit disruption in cognitive aging.

neuroscience↗