Biology subjects

Reinhold, K.

Publications and source records attributed to Reinhold, K..

5 recordsLinked to original sources

bioRxiv2026

A paradigm for skilled forelimb reaching by head-restrained mice

Forelimb reaching tasks are widely used in neuroscience across species. In mice, pellet reaching is especially useful because it requires fine motor control. However, few automated pellet-delivery systems are well suited for head-restrained reaching, where pellet position must be highly consistent. Here we present a complete pipeline for head-restrained, or head-fixed, forelimb reaching in mice. The pipeline includes a simple customizable pellet-presentation rig, an effective training protocol, and analysis code to detect reaches and classify their outcomes. To demonstrate pipeline utility, we quantified interruption of an ongoing reach. The temporal requirement for initiating cancellation was dependent on the phase of the reach, lengthening significantly as the reach neared completion. These results show that the pipeline can resolve fine phase-dependent features of skilled behavior and provide a practical framework for studying motor control in head-restrained mice.

neuroscience↗

bioRxiv2023

Maintenance and evolution of individual differences in a prey defence trait examined with a dynamic predator-prey model

Predator-prey systems often feature periodic population cycles. In an empirical system with a heritable prey defence trait, ecological oscillations were previously shown to cause evolution of prey defence on the timescale of the population cycles. In this paper, we develop an eco-evolutionary mathematical model comprising partial differential equations to investigate the evolutionary dynamics of prey defence during population cycles. We reveal that ecological population cycles induce evolutionary oscillations of the mean prey defence trait. In contrast to existing continuum modelling frameworks, our model allows for the evolution of individual variability. We show that eco-evolutionary oscillations select for increased individual variability close to the transition from stable to oscillatory states. We also reveal that evolution of prey defence requires both high efficiency and low cost of prey defence and highlight that more information on trade-offs between cost and efficiency is required.

evolutionary biology↗

bioRxiv2023

Evolution of individual variation in a competitive trait: a theoretical analysis

When competitive traits are costly, negative frequency-dependence can maintain genetic variance. Most theoretical studies examining this question assume binary polymorphisms, yet most trait variation in wild populations is continuous. We propose that continuous trait variation can result from continuous variation in resource quality and that the shape of the resource distribution determines trait maintenance. We used an individual-based model to test which conditions favour the stable maintenance of variation and which cause temporal fluctuations in trait values. This approach, inspired by contrasting outcomes of previous studies, clearly showed the decisive role played by the shape of resource distributions. Under extreme conditions, like the absence of resource variation or with very scarce resources for weak competitors, traits evolved to a single non-competitive or highly competitive strategy, respectively. Some distributions led to strong temporal fluctuations on trait values, whereas others led to the maintenance of large standing variation in competitive traits together with stable mean trait values. Our results thus explain the contradicting outcomes of previous theoretical studies and at the same time provide hypotheses to explain the maintenance of genetic variation and individual differences. We also suggest how the proposed effects of resource variation on trait maintenance can be tested empirically.

evolutionary biology↗

bioRxiv2023

Striatum supports fast learning but not memory recall

Animals learn to carry out motor actions in specific sensory contexts to achieve goals. The striatum has been implicated in producing sensory-motor associations, yet its contribution to memory formation or recall is not clear. To investigate the contribution of striatum to these processes, mice were taught to associate a cue, consisting of optogenetic activation of striatum-projecting neurons in visual cortex, with forelimb reaches to access food pellets. As necessary to direct learning, striatal neural activity encoded both the sensory context and outcome of reaching. With training, the rate of cued reaching increased, but brief optogenetic inhibition of striatal activity arrested learning and prevented trial-to-trial improvements in performance. However, the same manipulation did not affect performance improvements already consolidated into short- (within an hour) or long-term (across days) memories. Hence, striatal activity is necessary for trial-to-trial improvements in task performance, leading to plasticity in other brain areas that mediate memory recall.

neuroscience↗

bioRxiv2021

Brain state-dependent modulation of thalamic visual processing by cortico-thalamic feedback

The behavioral state of a mammal impacts how the brain responds to visual stimuli as early as in the dorsolateral geniculate nucleus of the thalamus (dLGN), the primary relay of visual information to the cortex. A clear example of this is the markedly stronger response of dLGN neurons to higher temporal frequencies of the visual stimulus in alert as compared to quiescent animals. The dLGN receives strong feedback from the visual cortex, yet whether this feedback contributes to these state-dependent responses to visual stimuli is poorly understood. Here we show that in mice, silencing cortico-thalamic feedback abolishes state-dependent differences in the response of dLGN neurons to visual stimuli. This holds true for dLGN responses to both temporal and spatial features of the visual stimulus. These results reveal that the state-dependent shift of the response to visual stimuli in an early stage of visual processing depends on cortico-thalamic feedback.

neuroscience↗