To label ipRGCs, a linearized mouse BAC20 (link) containing tdTomato was injected into B6SJL embryos, with transgenics backcrossed to C57BL/6J. Melanopsin immunostaining3 (link) confirmed specific expression. For recordings, mice (~P20–90) were dark-adapted overnight, anesthetized, enucleated, and euthanized. The retina was flat-mounted or dissociated (Supplementary Information S1 ). Aerated, heated bicarbonate-buffered Ames, containing synaptic blockers for flat-mount experiments, ran at ~5 ml/min through a 1-ml chamber. IpRGCs were visualized with seconds of fluorescence followed by infrared-DIC (Supplementary Information S1 ). Patch-clamp recordings used a KCl-based pipette solution (pH 7.2; see continued Methods ) supplemented with (in mM) 2 glutathione, 4 MgATP, and 0.3 Tris-GTP for whole-cell recordings or, alternatively, 125–250 μM amphotericin B for perforated-patch recording. For loose-patch recordings, the pipette contained HEPES-buffered Ames. Pipettes were parafilm-wrapped, and an Axopatch 200B in voltage-clamp or fast-current-clamp utilized (Supplementary Information S1 ). Recording stability was checked periodically with a test flash, and series resistance monitored. Vhold was −80 mV, initially for improving signal resolution though the photocurrent I–V relation was later shown to be rather shallow between −90 mV and −30 mV (Ref. 24 (link)). Liquid-junction potential was corrected. Photocurrent was low-pass filtered at 2 Hz (dim flashes) or 10 Hz (bright flashes) and membrane voltage at 10 kHz. Loose-patch recording bandwidth was 10 Hz - 1 kHz, sometimes with a notch filter. Sampling exceeded the Nyquist minimum. Flashes (10-nm bandwidth or occasionally white) were diffuse (730-μm diameter spot) or local (40-or 100-μm diameter), temporally spaced for full recovery between flashes (30–120 sec). White flashes, for response saturation, were converted to equivalent 480-nm flashes by response-matching (Supplementary Information S1 ). Consensual pupillary light reflex measurements followed previous work14 (link), with one eye of the unanesthetized mouse videoed under infrared and the other stimulated by Ganzfeld light (Supplementary Information S1 ). Data are mean ± S.D.
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Pupillary Reflex
Pupillary Reflex
The pupillary reflex, also known as the light reflex, is a physiological response of the pupil to changes in light intensity.
This involuntary reaction is controlled by the autonomic nervous system and serves to regulate the amount of light entering the eye, protecting the retina from damage.
The pupil constricts (becomes smaller) in bright light and dilates (becomes larger) in dim light, allowing the appropriate amount of light to reach the photoreceptors.
Studying the pupillary reflex can provide insights into the function of the visual system and the underlying neurological processes.
Researchers utilize this phenomenon to investigate a variety of ocular and neurological conditions, making it an important tool in clinical and experimental settings.
This involuntary reaction is controlled by the autonomic nervous system and serves to regulate the amount of light entering the eye, protecting the retina from damage.
The pupil constricts (becomes smaller) in bright light and dilates (becomes larger) in dim light, allowing the appropriate amount of light to reach the photoreceptors.
Studying the pupillary reflex can provide insights into the function of the visual system and the underlying neurological processes.
Researchers utilize this phenomenon to investigate a variety of ocular and neurological conditions, making it an important tool in clinical and experimental settings.
Most cited protocols related to «Pupillary Reflex»
Adenosine Triphosphate, Magnesium Salt
Amphotericin B
Animals, Transgenic
Bicarbonates
Embryo
Fluorescence
Glutathione
HEPES
Light
melanopsin
Mice, Laboratory
Mineralocorticoid Excess Syndrome, Apparent
Neoplasm Metastasis
Pupillary Reflex
Retina
tdTomato
Tissue, Membrane
Tromethamine
Adenosine Triphosphate, Magnesium Salt
Amphotericin B
Animals, Transgenic
Bicarbonates
Embryo
Fluorescence
Glutathione
HEPES
Light
melanopsin
Mice, Laboratory
Mineralocorticoid Excess Syndrome, Apparent
Neoplasm Metastasis
Pupillary Reflex
Retina
tdTomato
Tissue, Membrane
Tromethamine
The circadian response of ipRGCs and cone photoreceptors were determined during a
20–24 h laboratory test period, during which the participant remained
awake. On the day of testing, participants arrived at the laboratory at 8 am for
set-up and alignment in the pupillometer, and rinsed their mouth with water in
preparation for the first salivary collection, prior to the commencement of the
first pupil measurements at 9 am (Figure 4 ). To maximise pupil diameter (>6.5 mm), control retinal
illumination and minimise the effects of accommodation on pupil diameter, the
participant's right pupil was cyclopleged with 1.0% cyclopentolate.
Subjective accommodation was assessed using an optometer (Hartinger, Rodenstock)
and cyclopentolate was re-instilled as required. Exogenous circadian cues of
activity (minimum), sleep (none), posture (seated upright), caffeine (none),
ambient temperature (23–25°C), caloric intake (aliquots <500
kJ.hr−1) and ambient illumination (10 lux) [50] (link) were
controlled for the entire test duration.
Figure 4 is a flowchart
timeline of the hourly measurements procedures. At the start of each hour, after
alignment in the pupillometer, four pupil light reflex measurements were
recorded (2×488 nm; 2×610 nm). Salivary sample collection for dim
light melatonin onset (DLMO) was then completed according to standard protocols
[51] (link).
In between measurements, participants remained in an upright-seated position
with limited physical activity as monitored by the actigraph. The constant
laboratory illumination (10 lux) and repeated hourly delivery of an equivalent
stimulus energy for the pupil light reflex measurements allowed us to determine
if circadian variation in ipRGC and cone photoreceptor activity was independent
of environmental light.
20–24 h laboratory test period, during which the participant remained
awake. On the day of testing, participants arrived at the laboratory at 8 am for
set-up and alignment in the pupillometer, and rinsed their mouth with water in
preparation for the first salivary collection, prior to the commencement of the
first pupil measurements at 9 am (
illumination and minimise the effects of accommodation on pupil diameter, the
participant's right pupil was cyclopleged with 1.0% cyclopentolate.
Subjective accommodation was assessed using an optometer (Hartinger, Rodenstock)
and cyclopentolate was re-instilled as required. Exogenous circadian cues of
activity (minimum), sleep (none), posture (seated upright), caffeine (none),
ambient temperature (23–25°C), caloric intake (aliquots <500
kJ.hr−1) and ambient illumination (10 lux) [50] (link) were
controlled for the entire test duration.
timeline of the hourly measurements procedures. At the start of each hour, after
alignment in the pupillometer, four pupil light reflex measurements were
recorded (2×488 nm; 2×610 nm). Salivary sample collection for dim
light melatonin onset (DLMO) was then completed according to standard protocols
[51] (link).
In between measurements, participants remained in an upright-seated position
with limited physical activity as monitored by the actigraph. The constant
laboratory illumination (10 lux) and repeated hourly delivery of an equivalent
stimulus energy for the pupil light reflex measurements allowed us to determine
if circadian variation in ipRGC and cone photoreceptor activity was independent
of environmental light.
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Actigraphy
Caffeine
Cyclopentolate
Light
Lighting
Melatonin
Obstetric Delivery
Ocular Accommodation
Pupil
Pupillary Reflex
Retinal Cone
Sleep
Specimen Collection
Adult
Developmental Disabilities
Ethnicity
Face
Fear
Females
Head
Homo sapiens
Immune Tolerance
Light
Males
Pupil
Pupillary Reflex
A Tobii T120 infrared binocular eye tracker (Tobii Technology, Sweden) was used to record X and Y coordinates of eye position and pupil diameter. This video-based system consists of a high-resolution camera embedded in a 17-inch thin-film transistor LCD monitor (1,280 × 1,024 pixels resolution), which promotes more natural user behavior since it does not place restraints on participants such as a helmet, head-mounted sensor, or glasses. The eye tracker samples the position of the eyes at a rate of 120 Hz (one data point approximately every 10 ms, with an average precision of within 0.5° of visual angle).
Stimuli were identical to those used by Farzin et al. (2009 (link)). Images consisted of 60 colored photographs of adult human faces (equal numbers of males and females; different races and ethnicities) from the NimStim Face Stimulus Set (Tottenham et al. 2002 ), each face exhibiting a calm, happy, or fearful expression, and 60 scrambled versions of the face images. To insure that pupillary response to the onset of a face was independent of a pupillary light reflex, each face and corresponding scrambled image were matched on mean luminance, and equivalence was confirmed using a photometer (Minolta, LS-100, Osaka, Japan). Face images subtended a 12.12° by 17.19° region (the size of an actual human face) when viewed from a distance of 60 cm, and were presented on a standard 50% grey background (RGB: 128, 128, 128).
Stimuli were identical to those used by Farzin et al. (2009 (link)). Images consisted of 60 colored photographs of adult human faces (equal numbers of males and females; different races and ethnicities) from the NimStim Face Stimulus Set (Tottenham et al. 2002 ), each face exhibiting a calm, happy, or fearful expression, and 60 scrambled versions of the face images. To insure that pupillary response to the onset of a face was independent of a pupillary light reflex, each face and corresponding scrambled image were matched on mean luminance, and equivalence was confirmed using a photometer (Minolta, LS-100, Osaka, Japan). Face images subtended a 12.12° by 17.19° region (the size of an actual human face) when viewed from a distance of 60 cm, and were presented on a standard 50% grey background (RGB: 128, 128, 128).
Adult
Ethnicity
Eye
Eyeglasses
Face
Fear
Females
Head
Homo sapiens
Light
Males
Pupil
Pupillary Reflex
Most recents protocols related to «Pupillary Reflex»
Protocol full text hidden due to copyright restrictions
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Anesthesia
Anesthetics
Animals
Arecaceae
ARID1A protein, human
Aves
Base of Skull
Body Weight
Fingers
Foot
Fowls, Domestic
Head
Heart Auscultation
Human Body
Joint Dislocations
Ketamine
Ketaset
Light
Medetomidine
Medical Devices
Movement
Muscle Tonus
Neck
Operative Surgical Procedures
Pectoralis Muscles
Pharmaceutical Preparations
Pulse Rate
Pupillary Reflex
Reflex
Sternum
Therapeutics
Thumb
Veterinarian
Protocol full text hidden due to copyright restrictions
Open the protocol to access the free full text link
Anesthetic Effect
Autopsy
Consciousness
Joint Dislocations
Light
Microscopy
Movement
Neck
Pulse Rate
Pupillary Reflex
Reflex
A secondary analysis was performed on PLR data collected from a prospective cohort of adolescents between ages 12 and 19 years with pupillary light reflex (PLR) assessment conducted between 1 August 2017 and 11 May 2021, recruited from a specialty concussion program and private suburban high school, where some results from this cohort have been previously published [16 (link)]. The prospective observational cohort study was approved by the Children’s Hospital of Philadelphia institutional review board. Adolescents and/or their parents/legal guardians provided written assent/written informed consent. Pupillary light reflex metrics were measured via the same Neuroptics PLR-3000 handheld, infrared, automated, monocular pupillometer model used for the piglet portion of this study [46 (link)]. The pupillometer is approved by the US Food and Drug Administration and has been used in similar studies of mTBI in human adults and adolescents. The diagnosis of SRC was made by trained sports medicine pediatricians on the basis of the most recent Consensus Statement on Concussion in Sports [47 ], and all adolescents with concussion were assessed with pupillometry within 28 days of injury. Overall, PLR data from 167 healthy controls were used to establish a healthy RR for humans. PLR metrics for 177 concussed cases were obtained and compared to the healthy RR.
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Adolescent
Adult
Brain Concussion
Child
Diagnosis
Ethics Committees, Research
Homo sapiens
Injuries
Legal Guardians
Light
Parent
Pediatricians
Pupillary Reflex
The variables including sex, age, etiology, pupillary light reflex, GCS, absolute amplitude of N1 at electrode Fz (FzN1A), absolute amplitude of MMN at electrode Fz (FzMMNA), EEG background activity, sleep spindles, EEG-R, and PAV, which were generally considered to be associated with the prognosis of comatose patients. These 11 factors were preliminary screened, using the least absolute shrinkage and selection operator (LASSO) analysis. LASSO analysis was conducted with R software (version 4.2.1).
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Comatose
Light
Patients
Prognosis
Pupillary Reflex
Sleep
For this secondary analysis a subset of available parameters (features) was selected for the machine learning model based on the literature study and consensus of 3 experts (PW, MS, FD). We also, a priori, decided to exclude parameters with more than 20% missing values (Fig. 1 ).
The following data were included in the data set:
The dependent variable was TE (yes vs. no). Independent variables used for modelling (N = 28) included:
Patients’ characteristics at baseline: study centre (binarized at 50% of terminal extubation frequency, group1 < = 50%, group2 > 50%), age, sex, body mass index (BMI), acute physiology and chronic health evaluation II score at admission (APACHE)8 (link), chronic pre-existing medical condition (PreCond, yes/no), cardiac arrest with resuscitation before study inclusion (CPR, yes/no), admission diagnosis (3 most common categories one-hot encoded into dummy features: neurologic disorder (ADM_neuro), respiratory failure (ADM_resp), sepsis (ADM_sepsis); yes/no).
Patients’ characteristics at WLST: Glasgow coma scale (GCS), pupillary reflex (PUP, present vs. absent), cough (present vs. absent), mechanical ventilation mode (MV mode, controlled vs. supported), respiratory rate (RR, bpm), inspiratory fraction of oxygen (FiO2%), positive end expiratory pressure (PEEP, cmH2O), peak inspiratory pressure (PIP, cmH2O), intubation route (route, orotracheal intubation vs. tracheostomy), mean arterial pressure (MAP, mmHg), hear rate (HR, bmp), lactate (mmol L−1), arterial pH, arterial partial pressure of oxygen (PaO2, mmHg), arterial partial pressure of carbon dioxide (PaCO2, mmHg), total ranked circulatory drugs dose (circ_total_ranked), total ranked sedation drugs dose (sedation_total_ranked) and total ranked analgesics drugs dose at WLST (analgetics_total_ranked). Attempted donation after circulatory death was collected (DCD, yes/no).
The following data were included in the data set:
The dependent variable was TE (yes vs. no). Independent variables used for modelling (N = 28) included:
Patients’ characteristics at baseline: study centre (binarized at 50% of terminal extubation frequency, group1 < = 50%, group2 > 50%), age, sex, body mass index (BMI), acute physiology and chronic health evaluation II score at admission (APACHE)8 (link), chronic pre-existing medical condition (PreCond, yes/no), cardiac arrest with resuscitation before study inclusion (CPR, yes/no), admission diagnosis (3 most common categories one-hot encoded into dummy features: neurologic disorder (ADM_neuro), respiratory failure (ADM_resp), sepsis (ADM_sepsis); yes/no).
Patients’ characteristics at WLST: Glasgow coma scale (GCS), pupillary reflex (PUP, present vs. absent), cough (present vs. absent), mechanical ventilation mode (MV mode, controlled vs. supported), respiratory rate (RR, bpm), inspiratory fraction of oxygen (FiO2%), positive end expiratory pressure (PEEP, cmH2O), peak inspiratory pressure (PIP, cmH2O), intubation route (route, orotracheal intubation vs. tracheostomy), mean arterial pressure (MAP, mmHg), hear rate (HR, bmp), lactate (mmol L−1), arterial pH, arterial partial pressure of oxygen (PaO2, mmHg), arterial partial pressure of carbon dioxide (PaCO2, mmHg), total ranked circulatory drugs dose (circ_total_ranked), total ranked sedation drugs dose (sedation_total_ranked) and total ranked analgesics drugs dose at WLST (analgetics_total_ranked). Attempted donation after circulatory death was collected (DCD, yes/no).
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Analgesics
Arteries
Carbon dioxide
Cardiac Arrest
Cardiovascular System
Cough
Diagnosis
Disease, Chronic
Hearing
Index, Body Mass
Inhalation
Intubation
Lactate
Mechanical Ventilation
Nervous System Disorder
Oxygen
Partial Pressure
Patients
Pharmaceutical Preparations
Positive End-Expiratory Pressure
Pressure
Pupillary Reflex
Respiratory Failure
Respiratory Rate
Resuscitation
Sedatives
Septicemia
Tracheal Extubation
Tracheostomy
Tranquilizing Agents
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Cyclopentolate is a topical ophthalmic solution used in the medical field. It is a cycloplegic and mydriatic agent, primarily utilized for diagnostic purposes in eye examinations.
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Alcaine is a topical ophthalmic solution. It contains the active ingredient proparacaine hydrochloride, which is a local anesthetic used to numb the eye's surface.
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The ARK-510A is an automated refractometer designed for eye examinations. It measures the refractive power of the eye and provides data on the corneal curvature. The device is intended for use in ophthalmology and optometry practices.
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Tropicamide is a mydriatic and cycloplegic agent used in ophthalmic examinations and procedures. It is a pharmaceutical product designed to temporarily dilate the pupil and temporarily paralyze the ciliary muscle, which controls the eye's focusing ability.
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More about "Pupillary Reflex"
Pupillary Light Reflex, Pupillary Response, Pupil Constriction, Pupil Dilation, Autonomic Nervous System, Visual System, Retinal Damage, Photoreceptors, Ocular Conditions, Neurological Disorders, Mydrin-P, SL-15, Cyclopentolate, Alcaine, IOLMaster 500, ARK-510A, IOL Master, Tropicamide, RK-F1, Direct Ophthalmoscope.
The pupillary reflex, also known as the light reflex, is a physiological response of the pupil to changes in light intensity.
This involuntary reaction is controlled by the autonomic nervous system and serves to regulate the amount of light entering the eye, protecting the retina from damage.
The pupil constricts (becomes smaller) in bright light and dilates (becomes larger) in dim light, allowing the appropriate amount of light to reach the photoreceptors.
Studying the pupillary reflex can provide insights into the function of the visual system and the underlying neurological processes.
Researchers utilize this phenomenon to investigate a variety of ocular and neurological conditions, making it an important tool in clinical and experimental settings.
PubCompare.ai's AI-driven protocol optimization can help you unlock the power of the pupillary reflex and enhance your research accuracy.
Discover how this innovative tool can help you locate the best protocols from literature, pre-prints, and patents through intelligent comparisons, and experience the future of research today!
The pupillary reflex, also known as the light reflex, is a physiological response of the pupil to changes in light intensity.
This involuntary reaction is controlled by the autonomic nervous system and serves to regulate the amount of light entering the eye, protecting the retina from damage.
The pupil constricts (becomes smaller) in bright light and dilates (becomes larger) in dim light, allowing the appropriate amount of light to reach the photoreceptors.
Studying the pupillary reflex can provide insights into the function of the visual system and the underlying neurological processes.
Researchers utilize this phenomenon to investigate a variety of ocular and neurological conditions, making it an important tool in clinical and experimental settings.
PubCompare.ai's AI-driven protocol optimization can help you unlock the power of the pupillary reflex and enhance your research accuracy.
Discover how this innovative tool can help you locate the best protocols from literature, pre-prints, and patents through intelligent comparisons, and experience the future of research today!