Biology subjects

Yahiro, T.

Publications and source records attributed to Yahiro, T..

6 recordsLinked to original sources

bioRxiv2026

iFLiP: accessible and low-cost lifetime fiber photometry for robust longitudinal and quantitative measurements of neural dynamics

Fluorescence lifetime measurements overcome the limitation of widely used intensity-based measurements in quantifying tonic activities and longitudinal changes in neural dynamics. However, while lifetime sensors are rapidly emerging, their applications have been limited by the complexity and expense of required hardware and software. Here, we report a simple, low-cost lifetime fiber photometry system, named iFLiP, that uses entirely off-the-shelf products and can be assembled without specialized expertise. We also develop software that enables turn-key operation. The integrated system can accurately monitor lifetime changes at up to 5000 Hz for days. We demonstrate the utility of iFLiP in monitoring the activity of protein kinase A (PKA) in vitro and in vivo, and uncover striatal subregion- and cell-type-specific PKA dynamics elicited by locomotion in mice. Additionally, multi-day continuous measurements in the basal forebrain reveal previously unappreciated PKA activity associated with sleep/wakefulness. Overall, iFLiP may make lifetime measurements broadly accessible in neuroscience research.

neuroscience↗

bioRxiv2026

Spatial patterns of mosquito communities and monkey malaria vectors in a tropical riverine forest in Sabah, Malaysian Borneo

Understanding how vector ecology intersects with host behaviour is essential for predicting zoonotic disease risk in tropical ecosystems. We conducted a two-year field study (November 2016-October 2018) in a riverine forest in Sabah, Malaysian Borneo, to characterize mosquito communities and the spatial distribution of potential simian-malaria vectors. Mosquitoes were sampled on 44 nights using CO{square}-baited light traps repeatedly deployed along a 500 m transect at three distances from the river (0, 250, 500 m) and two vertical strata (ground and canopy), yielding 244 trap collections across repeated sampling nights. In total, 9,928 mosquitoes were collected, dominated by Culex spp. (9,079; 91.4%), whereas Anopheles spp. were rare (153; 1.5%); most remaining specimens were unidentified to genus, and species-level identification was limited primarily to Anopheles. Nevertheless, female Anopheles (n=57) were more frequently detected near the river and less commonly at intermediate distance, and tended to be captured more often in ground traps. Zero-inflated negative binomial GLMMs based on the full mosquito dataset indicated significant effects of river distance and height on mosquito abundance, while night-time temperature and humidity showed no detectable effects. The zero-inflated structure of the data further suggested that many zero captures reflected true absence rather than sampling variability. The Anopheles assemblage was dominated by An. balabacensis, and molecular screening of 57 females detected simian Plasmodium DNA in two individuals. Overall, these findings suggest that river-edge habitats may represent localized areas where vectors persist and where primates and human activities overlap, creating repeated opportunities for host-vector contact even when vector densities are low.

ecology↗

bioRxiv2025

Cerebellar climbing fibers convey perceptual choice during decision-making

Cerebellar climbing fibers are thought to signal reward prediction errors in non-motor functions. By imaging postsynaptic responses of climbing fibers onto mouse Purkinje cell dendrites during auditory discrimination, we found that climbing fibers in crus I can encode cue identities or perceptual choices. These responses were reshaped by reversal learning. Optogenetic perturbation of climbing fiber activity impaired discrimination. These results suggest a feedforward role of climbing fibers in perceptual decision-making.

neuroscience↗

bioRxiv2024

A high-performance genetically encoded sensor for cellular imaging of PKC activity in vivo

We report a genetically encoded fluorescence lifetime sensor for protein kinase C (PKC) activity, named CKAR3, based on Forster resonance energy transfer. CKAR3 exhibits a 10-fold increased dynamic range compared to its parental sensors and enables in vivo imaging of PKC activity during animal behavior. Our results reveal robust PKC activity in a sparse neuronal subset in the motor cortex during locomotion, in part mediated by muscarinic acetylcholine receptors.

neuroscience↗

bioRxiv2023

Two Ascending Thermosensory Pathways from the Lateral Parabrachial Nucleus That Mediate Behavioral and Autonomous Thermoregulation

Thermoregulatory behavior in homeothermic animals is an innate behavior to defend body core temperature from environmental thermal challenges in coordination with autonomous thermoregulatory responses. In contrast to the progress in understanding the central mechanisms of autonomous thermoregulation, those of behavioral thermoregulation remain poorly understood. We have previously shown that the lateral parabrachial nucleus (LPB) mediates cutaneous thermosensory afferent signaling for thermoregulation. To understand the thermosensory neural network for behavioral thermoregulation, in the present study, we investigated the roles of ascending thermosensory pathways from the LPB in avoidance behavior from innocuous heat and cold in rats. Neuronal tracing revealed two segregated groups of LPB neurons projecting to the median preoptic nucleus (MnPO), a thermoregulatory center (LPB[->]MnPO neurons), and those projecting to the central amygdaloid nucleus (CeA), a limbic emotion center (LPB[->]CeA neurons). While LPB[->]MnPO neurons include separate subgroups activated by heat or cold exposure of rats, LPB[->]CeA neurons were only activated by cold exposure. By selectively inhibiting LPB[->]MnPO or LPB[->]CeA neurons using tetanus toxin light chain or chemogenetic or optogenetic techniques, we found that LPB[->]MnPO transmission mediates heat avoidance, whereas LPB[->]CeA transmission contributes to cold avoidance. In vivo electrophysiological experiments showed that skin cooling-evoked thermogenesis in brown adipose tissue requires not only LPB[->]MnPO neurons but also LPB[->]CeA neurons, providing a novel insight into the central mechanism of autonomous thermoregulation. Our findings reveal an important framework of central thermosensory afferent pathways to coordinate behavioral and autonomous thermoregulation and to generate the emotions of thermal comfort and discomfort that drive thermoregulatory behavior.

neuroscience↗

bioRxiv2022

Prostaglandin EP3 receptor-expressing preoptic neurons bidirectionally control body temperature via tonic GABAergic signaling

The circuit mechanism of the thermoregulatory center in the preoptic area (POA) is unknown. Using rats, here we show prostaglandin EP3 receptor-expressing POA neurons (POAEP3R neurons) as a pivotal bidirectional controller in the central thermoregulatory mechanism. POAEP3R neurons are activated in response to elevated ambient temperature, but inhibited by prostaglandin E2, a pyrogenic mediator. Chemogenetic stimulation of POAEP3R neurons at room temperature reduces body temperature by enhancing heat dissipation, whereas inhibition of them elicits hyperthermia involving brown fat thermogenesis, mimicking fever. POAEP3R neurons innervate sympathoexcitatory neurons in the dorsomedial hypothalamus (DMH) via tonic inhibitory signaling. Although many POAEP3R neuronal cell bodies express a glutamatergic mRNA marker, paradoxically, their axons in the DMH predominantly contain terminals with GABAergic presynaptic proteins, which are increased by chronic heat exposure. These findings indicate that tonic GABAergic inhibitory signaling from POAEP3R neurons is a fundamental determinant of body temperature for thermal homeostasis and fever.

physiology↗