Biology subjects

Dickson, M.

Publications and source records attributed to Dickson, M..

4 recordsLinked to original sources

bioRxiv2026

Anatomical mapping of dopamine D1 and muscarinic M4 receptor

Dopamine D1 receptors (D1R) and muscarinic M4 receptors (M4R) regulate overlapping functions in the cortex and the striatum, but the cellular relationship between D1R- and M4R-associated populations across brain regions remains incompletely defined. Using D1R-tdTomato/M4R-EGFP double-reporter mice, we quantified tdTomato-only, EGFP-only, and coexpressing cellular populations across the dorsal striatum, nucleus accumbens, and medial prefrontal cortex in 18 animals. Reporter composition differed strongly by anatomical region. Coexpression was prominent throughout the dorsal striatum and greatest in the dorsomedial striatum, whereas the nucleus accumbens shifted toward greater tdTomato-only and reduced EGFP-only representation, particularly in the core. In contrast, the medial prefrontal cortex was dominated by EGFP-only cells. These regional patterns were broadly retained across sex and age. HCR-FISH further supported spatial correspondence between endogenous Drd1 and Chrm4 transcript signal and the respective fluorescent reporters. Together, these findings demonstrate region-dependent organization of D1R- and M4R-associated cellular populations across the cortex and striatum and define distinct anatomical contexts in which M4R-directed signaling may influence D1R-associated neurons.

neuroscience↗

bioRxiv2026

Adaptation of white adipocytes to cooler temperatures: impacts on energy metabolism and protein acetylation

Adipocytes throughout the body reside in distinct thermal environments. Visceral adipocytes within the body core are maintained near 37 {degrees}C, whereas those in bone marrow, subcutaneous, and dermal depots occupy cooler regions within the peripheral shell. While brown and beige adipocyte responses to cold stress are well characterized, much less is known about how white adipocytes adapt to moderately reduced temperatures below 37 {degrees}C. Our recent work revealed that cultured adipocytes exposed to 31 {degrees}C, a temperature representative of distal adipose regions, exhibit enhanced mitochondrial function, including increased substrate oxidation and ATP turnover, yet the mechanisms underlying this upregulation remain unclear. Here we show that adaptation to cool temperatures leads to a widespread decrease in protein acetylation in both undifferentiated and differentiated adipocytes, independent of nutrient status, and that this change is readily reversible upon rewarming. Subcellular fractionation and immunoblotting demonstrate that the hypoacetylation coincides with a compartment-specific enrichment of acetylated proteins within mitochondria, indicating selective remodeling of the mitochondrial acetylome. Transcriptomic and biochemical analyses reveal that these temperature-dependent changes occur without alterations in acetyltransferase or deacetylase expression, NAD concentration, or acetyl-CoA availability, suggesting regulation through alternative mechanisms affecting acetyl-CoA flux or enzyme activity. Integrative acetyl-proteomic and metabolomic profiling identifies mitochondrial enzymes, including serine hydroxymethyltransferase 2 (SHMT2) and propionyl-CoA carboxylase (PCCA), whose acetylation correlates closely with changes in associated metabolite pools. Together, these findings establish physiologically relevant cooling as a cell-autonomous regulator of mitochondrial protein acetylation and metabolic adaptation in adipocytes.

cell biology↗

bioRxiv2024

Non-invasive laser speckle imaging of extra-embryonic blood vessels in intact few-days-old avian eggs

Imaging blood vessels in early-stage avian embryos has a wide range of practical applications for developmental biology studies, drug and vaccine testing, and early sex determination. Optical imaging such as brightfield transmission imaging offers a compelling solution due to its safe non-ionizing radiation, and operational benefits. However, it comes with challenges such as eggshell opacity and light scattering. To address these, we have revisited an approach based on laser speckle contrast imaging (LSCI) and demonstrated a high quality, comprehensive and non-invasive visualization of blood vessels in few-days-old chicken eggs, with blood vessel as small as 100 {micro}m in diameter (with LSCI profile full-width-at-half-maximum of 275 {micro}m). We present its non-invasive use for monitoring blood flow, measuring the embryos heartbeat, and determining the embryos developmental stages using machine learning with 85% accuracy from stage HH15 to HH22. This method can potentially be used for non-invasive longitudinal studies of cardiovascular development and angiogenesis, as well as egg screening for the poultry industry.

bioengineering↗

bioRxiv2018

The effect of education on adult mortality, health, and income: triangulating across genetic and policy reforms

1On average, educated people are healthier, wealthier and have higher life expectancy than those with less education. Numerous studies have attempted to determine whether these differences are caused by education, or are merely correlated with it and are ultimately caused by another factor. Previous studies have used a range of natural experiments to provide causal evidence. Here we exploit two natural experiments, perturbation of germline genetic variation associated with education which occurs at conception, known as Mendelian randomization, and a policy reform, the raising of the school leaving age in the UK in 1972. Previous studies have suggested that the differences in outcomes associated with education may be due to confounding. However, the two independent sources of variation we exploit largely imply consistent causal effects of education on outcomes much later in life.

epidemiology↗