Biology subjects

Mills, W.

Publications and source records attributed to Mills, W..

3 recordsLinked to original sources

bioRxiv2026

Complex trait responses to complex environments: how do larval amphibians navigate co-occurring ecological demands that influence the same traits?

O_LIMany organisms alter phenotypically plastic traits in response to environmental cues to match their phenotypes with variable environments. In larval amphibians, development and growth rates respond to spatiotemporally variable mortality risk from predation, wetland drying, or resource limitation. However, these rates are also temperature-dependent for ectotherms. Although wild animals experience these factors simultaneously (e.g., thermal regimes, predation risk, resource limitation), most studies investigate their impacts in isolation, limiting our understanding of how they interact across ecological contexts. C_LIO_LIHere we simultaneously exposed larval Plains Leopard Frogs (Lithobates blairi) to varying resource levels and predation risk treatments across a thermal regime to investigate the joint effects of these ecological drivers on growth and development rates and their consequences for size and vagility after metamorphosis. We crossed two predation treatments (waterborne cues from Procambarus gracilis fed L. blairi larvae, control water) with three food resource levels (5%, 25%, 50% of body mass) and six thermal regimes (diel {+/-} 3{degrees}C cycles of 15, 20, 22, 24, 26, 28{degrees}C), replicating each combination five times for a total of 180 individuals. We recorded growth and development rates and completion of metamorphosis, then measured juvenile body size and jumping performance. C_LIO_LIThe number of larvae completing metamorphosis was primarily determined by temperature and temperature-dependent effects of resource limitation. Percent metamorphosis peaked at intermediate temperatures when resources were high and were higher in predation-risk treatments at the warmest temperatures. Under high resources, development and growth rates showed unimodal thermal responses that were absent when resources were constrained. Higher resources increased development rates, but proportional increases in growth maintained constant body size across temperatures. Post-metamorphic body size differed only by predation treatment, with predator-exposed individuals being smaller. Juvenile jumping performance increased with body size and individuals raised with high resources without predator cues exhibited the highest performance. C_LIO_LIThe absence of temperature effects on size at metamorphosis reflected unexpected coupling of growth and development rates across treatments, producing uniform body sizes. This pattern contrasts with the temperature-size rule and suggests that plastic responses may exhibit selection for a minimum viable size at metamorphosis. C_LI

ecology↗

bioRxiv2020

Spatially expandable fiber-based probes as a multifunctional deep brain interface

Understanding the cytoarchitecture and wiring of the brain requires improved methods to record and stimulate large groups of neurons with cellular specificity. This requires miniaturized neural interfaces that integrate into brain tissue without altering its properties. Existing neural interface technologies have been shown to provide high-resolution electrophysiological recording with high signal-to-noise ratio. However, with single implantation, the physical properties of these devices limit their access to one, small brain region. To overcome this limitation, we developed a platform that provides three-dimensional coverage of brain tissue through multisite multifunctional fiber-based neural probes guided in a helical scaffold. Chronic recordings from the spatially expandable fiber probes demonstrate the ability of these fiber probes capturing brain activities with a single-unit resolution for long observation times. Furthermore, using Thy1-ChR2-YFP mice we demonstrate the application of our probes in simultaneous recording and optical/chemical modulation of brain activities across distant regions. Similarly, varying electrographic brain activities from different brain regions were detected by our customizable probes in a mouse model of epilepsy, suggesting the potential of using these probes for the investigation of brain disorders such as epilepsy. Ultimately, this technique enables three-dimensional manipulation and mapping of brain activities across distant regions in the deep brain with minimal tissue damage, which can bring new insights for deciphering complex brain functions and dynamics in the near future.

bioengineering↗

bioRxiv2017

LRRTM1 underlies synaptic convergence in visual thalamus

It has long been thought that the mammalian visual system is organized into parallel pathways, with incoming visual signals being parsed in the retina based on feature (e.g. color, contrast and motion) and then transmitted to the brain in unmixed, feature-specific channels. To faithfully convey feature-specific information from retina to cortex, thalamic relay cells must receive inputs from only a small number of functionally similar retinal ganglion cells. However, recent studies challenged this by revealing substantial levels of retinal convergence onto relay cells. Here, we sought to identify mechanisms responsible for the assembly of such convergence. Using an unbiased transcriptomics approach and targeted mutant mice, we discovered a critical role for the synaptic adhesion molecule Leucine Rich Repeat Transmembrane Neuronal 1 (LRRTM1) in the emergence of retinothalamic convergence. Importantly, LRRTM1 mutant mice display impairment in visual behaviors, suggesting a functional role of retinothalamic convergence in vision.

neuroscience↗