A5057681413- Circadian rhythm and melatonin
- Photoreceptor and optogenetics research
- Retinal Development and Disorders
- Neuroscience and Neuropharmacology Research
- Sleep and Wakefulness Research
- Olfactory and Sensory Function Studies
- Spaceflight effects on biology
- Neurobiology and Insect Physiology Research
- Bat Biology and Ecology Studies
- Impact of Light on Environment and Health
- Thermoregulation and physiological responses
- Neural dynamics and brain function
- Neuroscience of respiration and sleep
- melanin and skin pigmentation
- Genetic Neurodegenerative Diseases
- Genetics, Aging, and Longevity in Model Organisms
- Thermal Regulation in Medicine
- Effects of Environmental Stressors on Livestock
- Infrared Thermography in Medicine
- Dye analysis and toxicity
- Biochemical Analysis and Sensing Techniques
- Dietary Effects on Health
- Mitochondrial Function and Pathology
- Adipose Tissue and Metabolism
- Memory and Neural Mechanisms
University of Oxford
2012-2022
John Radcliffe Hospital
2012-2021
Oxford Centre for Computational Neuroscience
2020
Canadian Sleep & Circadian Network
2018
Neuroscience Institute
2018
University College London
2002-2005
Light exerts widespread effects on physiology and behaviour. As well as the widely-appreciated role of light in vision, also plays a critical many non-visual responses, including regulating circadian rhythms, sleep, pupil constriction, heart rate, hormone release learning memory. In mammals, responses to are all mediated via retinal photoreceptors, classical rods cones involved vision recently identified melanopsin-expressing photoreceptive ganglion cells (pRGCs). Understanding laboratory...
Sleep is a fundamental biological rhythm involving the interaction of numerous brain structures and diverse neurotransmitter systems. The primary measures used to define sleep are electroencephalogram (EEG) electromyogram (EMG). However, EEG-based methods often unsuitable for use in high-throughput screens as they time-intensive involve invasive surgery. As such, dissection mechanisms discovery novel drugs that modulate would benefit greatly from further development rapid behavioral assays...
Light plays a critical role in the regulation of numerous aspects physiology and behaviour, including entrainment circadian rhythms sleep. These responses involve melanopsin (OPN4)-expressing photosensitive retinal ganglion cells (pRGCs) addition to rods cones. Nocturnal light exposure rodents has been shown result rapid sleep induction, which key role. However, studies have also that can elevated corticosterone, response is not compatible with To investigate these contradictory findings...
Abstract TRPM1 is a spontaneously active non‐selective cation channel that has recently been shown to play an important role in the depolarizing light responses of ON bipolar cells. Consistent with this role, mutations gene have identified as principal cause congenital stationary night blindness. However, previous microarray studies Trpm1 and Trpm3 are acutely regulated by eyes mice lacking rods cones ( rd/rd cl ), finding consistent non‐image‐forming photoreception. In study we show...
Accurately measuring activity and feeding is frequently important in laboratory animal research, whether for welfare-monitoring or experimental recording. Quantification commonly involves manual pellet-weighing; however, this can physically disturb animals cannot continuously assess both the amount pattern of feeding. Improved means food-intake measurement have been developed yet are often costly incompatible with cage configurations. We therefore validated SnackerTracker—a cost-effective,...
Melanopsin (OPN4) is a retinal photopigment that mediates wide range of non-image-forming (NIF) responses to light [1Freedman M.S. Lucas R.J. Soni B. von Schantz M. Muñoz David-Gray Z. Foster R. Regulation mammalian circadian behavior by non-rod, non-cone, ocular photoreceptors.Science. 1999; 284: 502-504Crossref PubMed Scopus (644) Google Scholar, 2Hattar S. Mrosovsky N. Thompson Douglas R.H. Hankins M.W. Lem J. Biel Hofmann F. R.G. Yau K.W. and rod-cone photoreceptive systems account for...
Significance In modern societies, people are regularly exposed to artificial light (e.g., light-emitting electronic devices). Dim in the evening (DLE) imposes an extension of solar day, increasing our alertness before bedtime, delaying melatonin timing and sleep onset, sleepiness next morning. Using laboratory mice as a model organism, we show that 2 wk 4-h, 20-lux DLE postpones rest–activity rhythms, delays molecular rhythms brain body, reverses diurnal pattern short-term memory...
Abstract Body temperature is an important physiological parameter in many studies of laboratory mice. Continuous assessment body has traditionally required surgical implantation a telemeter, but this invasive procedure adversely impacts animal welfare. Near-infrared thermography provides non-invasive alternative by continuously measuring the highest on outside (T skin ), reliability these recordings as proxy for continuous core ) measurements not been assessed. Here, T (30 s resolution) and...
Abstract Study Objectives Torpor is a regulated and reversible state of metabolic suppression used by many mammalian species to conserve energy. Whereas the relationship between torpor sleep has been well-studied in seasonal hibernators, less known about effects fasting-induced on states vigilance brain activity laboratory mice. Methods Continuous monitoring electroencephalogram (EEG), electromyogram (EMG), surface body temperature was undertaken adult, male C57BL/6 mice over consecutive...
Circadian deficits in Huntington's disease (HD) are recapitulated both fragment (R6/2) and full-length (Q175) mouse models of HD. rhythms regulated by the suprachiasmatic nuclei (SCN) hypothalamus, which primarily entrained light detected retina. The SCN receives input from intrinsically photosensitive retinal ganglion cells (ipRGCs) that express photopigment melanopsin, but also receive rods cones. In turn, ipRGCs mediate a range non-image forming responses to including circadian...
Cryptochromes 1 and 2 (CRY1/2) are key components of the negative limb mammalian circadian clock. Like many peripheral tissues, Cry1 -2 expressed in retina, where they thought to play a role regulating rhythmic physiology. However, studies differ consensus as their localization function, CRY1 immunostaining has not been convincingly demonstrated retina. Here we describe expression function mouse retina both sexes. Unexpectedly, show that is throughout all retinal layers, whereas CRY2...
Mistimed exposure to light has been demonstrated negatively affect multiple aspects of physiology and behavior. Here we analyzed the effects chronic abnormal lighting conditions in mice. We exposed mice for 1 year either: a standard light/dark cycle, "light-pollution" condition which low levels were present dark phase circadian cycle (dim at night, DLAN), or altered cycles length weekday weekend differed by 6 h ("social jetlag"). Mice exhibited several activity phenotypes, as well changes...
Abstract Mutations in transcription factors often exhibit pleiotropic effects related to their complex expression patterns and multiple regulatory targets. One such mutation the zinc finger homeobox 3 (ZFHX3) factor, short circuit ( Sci , Zfhx3 Sci/+ ), is associated with significant circadian deficits mice. However, given evidence of its retinal expression, we set out establish on function using molecular, cellular, behavioral electrophysiological measures. Immunohistochemistry confirms...
Group I metabotropic glutamate receptors (mGluRs) are expressed in cells the superficial layers of rat superior colliculus (SSC) and SSC afferents. The purpose this study was to investigate physiological effect mGluR activation on visual responses neurones using both vivo vitro techniques. In preparation, agonists antagonists were applied by iontophoresis single neurone activity recorded extracellularly anaesthetised rats. Application agonist ( S )‐3,5‐dihydroxyphenylglycine (DHPG) resulted...
Melanopsin (OPN4) is an opsin photopigment expressed within intrinsically photosensitive retinal ganglion cells (ipRGCs) that mediate non-image forming (NIF) responses to light. Two single-nucleotide polymorphisms (SNPs) in human melanopsin (hOPN4), Pro10Leu and Thr394Ile, have recently been associated with abnormal NIF light, including seasonal affective disorder. It has suggested these behavioural changes are due altered signalling. However, there currently no direct evidence support this....
Light plays a critical role in regulating physiology and behavior, including both visual non-visual responses. In mammals, loss of eyes abolishes all these responses, demonstrating that the photoreceptors involved are exclusively ocular. By contrast, many non-mammalian species possess extra-ocular located pineal complex deep brain. Whilst there have been suggestions photoreception man, evidence for is limited. One approach to objectively determine presence such receptors measure brain...
Abstract Torpor is a regulated reversible state of metabolic suppression used by many mammalian species to conserve energy. Although torpor has been studied extensively in terms general physiology, metabolism and neuroendocrinology, the effects hypometabolism associated hypothermia on brain activity states vigilance have received little attention. Here we performed continuous monitoring electroencephalogram (EEG), electromyogram (EMG) peripheral body temperature adult, male C57BL/6 mice over...