Biology subjects

Wood, C. M.

Publications and source records attributed to Wood, C. M..

3 recordsLinked to original sources

bioRxiv2023

Subcallosal area 25: its responsivity to the stress hormone cortisol and its opposing effects on appetitive motivation in marmosets

Aberrant activity in caudal subcallosal anterior cingulate cortex (scACC) is implicated in depression and anxiety symptomatology, with its normalisation a putative biomarker of successful treatment response. The function of scACC in emotion processing and mental health is not fully understood despite its known influence on stress-mediated processes through its rich expression of mineralocorticoid and glucocorticoid receptors. Here we examine the causal interaction between area 25 within scACC (scACC-25) and the stress hormone, cortisol, in the context of anhedonia and anxiety-like behaviour. Moreover, the overall role of scACC-25 in hedonic capacity and motivation is investigated under transient pharmacological inactivation and overactivation. The results suggest that a local increase of cortisol in scACC-25 shows a rapid induction of anticipatory anhedonia and increased responsiveness to uncertain threat. Separate inactivation and overactivation of scACC-25 increased and decreased motivation and hedonic capacity, respectively, likely through different underlying mechanisms. Together, these data show that area scACC-25 has a causal role in consummatory and motivational behaviour and produces rapid responses to the stress hormone cortisol, that mediates anhedonia and anxiety-like behaviour.

animal behavior and cognition↗

bioRxiv2023

The pore-forming apolipoprotein APOL7C drives phagosomal rupture and antigen cross-presentation by dendritic cells

Type I conventional dendritic cells (cDC1s) are essential for the generation of protective cytotoxic T lymphocyte (CTL) responses against many types of viruses and tumours. They do so by internalizing antigens from virally infected or tumour cells and presenting them to CD8+ T cells in a process known as cross-presentation (XP). Despite the obvious biological importance of XP, the molecular mechanism(s) driving this process remain unclear. Here, we show that a cDC-specific pore-forming protein called apolipoprotein 7C (APOL7C) is upregulated in response to innate immune stimuli and is recruited to phagosomes. Strikingly, the association of APOL7C with phagosomes leads to phagosomal rupture, which in turn allows for the escape of engulfed protein antigens to the cytosol where they can be processed via the endogenous major histocompatibility complex (MHC) class I antigen processing pathway. We show that APOL7C recruitment to phagosomes is voltage-dependent and occurs in response to NADPH oxidase-induced depolarization of the phagosomal membrane. Our data indicate the presence of dedicated pore-forming apolipoproteins that mediate the delivery of phagocytosed proteins to the cytosol of activated cDC1s to facilitate MHC class I presentation of exogenous antigen and to regulate adaptive immunity.

cell biology↗

bioRxiv2022

DNA metabarcoding reveals the threat of rapidly expanding barred owl populations to native wildlife in western North America

Invasive predators can have detrimental impacts on native species and biological communities through direct consumptive effects and indirect effects on trophic interactions. As an invasive, apex predator achieving high densities, barred owls (Strix varia) may pose a substantial threat to native wildlife in western North American forests. Studies of the trophic ecology of barred owls in their invasive range, however, have involved morphological examinations of prey remains with limited taxonomic resolution. We conducted DNA metabarcoding using intestinal samples collected from barred owls at the leading edge of their range expansion in northeastern California. Using customized primers, we screened the intestinal contents of 124 barred owls and detected a broad diet of 78 unique prey types (48 vertebrates and 30 invertebrates), including many previously undetected prey types. Mammals were the most consumed vertebrate class (frequency of occurrence = 65%), followed by amphibians (32%), birds (22%), and reptiles (19%). Diets differed regionally but were similar among ages and sexes and exhibited limited variation in response to local environmental conditions. Our work highlights the generalist predatory strategy of invasive barred owls, indicates that they will not serve as ecological replacements for the congeneric spotted owls (S. occidentalis) they displace, and identifies numerous native species potentially threatened by their range expansion. Expanding currently limited barred owl removals could benefit native species and wildlife communities in western North America. More broadly, DNA metabarcoding provides a powerful tool for conducting detailed assessments of species consumed by invasive predators, potentially incentivizing conservation actions and improving outcomes.

ecology↗