Dynamic changes of timing precision in timed actions during a behavioural task in guinea pigs

AbstractTemporal precision is a determinant of performance in various motor activities. Although the accuracy and precision of timing in activities have been previously measured and quantified, temporal dynamics with flexible precision have not been considered. Here, we examined the temporal dynamics in timed motor activities (timed actions) using a guinea pig model in a behavioural task requiring an animal to control action timing to obtain a water reward. In well-trained animals, momentary variations in timing precision were extracted from the temporal distribution of the timed actions measured over daily 12-h sessions. The resampling of the observed time of action in each session demonstrated significant changes of timing precision within a session. Periods with higher timing precision appeared indiscriminately during the same session, and such periods lasted ~ 20 min on average. We conclude that the timing precision in trained actions is flexible and changes dynamically in guinea pigs. By elucidating the brain mechanisms involved in flexibility and dynamics with an animal model, future studies should establish more effective methods to actively enhance timing precision in our motor activities, such as sports.

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Stability and flexibility in multisensory sampling: insights from perceptual illusions

Journal of Neurophysiology ◽

10.1152/jn.00060.2019 ◽

2019 ◽

Vol 121 (5) ◽

pp. 1588-1590 ◽

Cited By ~ 3

Author(s):

Luca Casartelli

Keyword(s):

Temporal Dynamics ◽

Multisensory Processing ◽

General Idea ◽

Perceptual Illusions ◽

The Brain ◽

Multisensory Processes

Neural, oscillatory, and computational counterparts of multisensory processing remain a crucial challenge for neuroscientists. Converging evidence underlines a certain efficiency in balancing stability and flexibility of sensory sampling, supporting the general idea that multiple parallel and hierarchically organized processing stages in the brain contribute to our understanding of the (sensory/perceptual) world. Intriguingly, how temporal dynamics impact and modulate multisensory processes in our brain can be investigated benefiting from studies on perceptual illusions.

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Intravitreal brimonidine inhibits form-deprivation myopia in guinea pigs

Eye and Vision ◽

10.1186/s40662-021-00248-0 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Yifang Yang ◽

Junshu Wu ◽

Defu Wu ◽

Qi Wei ◽

Tan Zhong ◽

...

Keyword(s):

Guinea Pig ◽

Intravitreal Injection ◽

Guinea Pigs ◽

Intravitreal Injections ◽

Eye Drops ◽

Rna Seq ◽

Myopia Progression ◽

Expression Levels ◽

Guinea Pig Model ◽

Administration Methods

Abstract Background The use of ocular hypotensive drugs has been reported to attenuate myopia progression. This study explores whether brimonidine can slow myopia progression in the guinea pig form-deprivation (FD) model. Methods Three-week-old pigmented male guinea pigs (Cavia porcellus) underwent monocular FD and were treated with 3 different methods of brimonidine administration (eye drops, subconjunctival or intravitreal injections). Four different concentrations of brimonidine were tested for intravitreal injection (2 μg/μL, 4 μg/μL, 20 μg/μL, 40 μg/μL). All treatments continued for a period of 21 days. Tonometry, retinoscopy, and A-scan ultrasonography were used to monitor intraocular pressure (IOP), refractive error and axial length (AL), respectively. On day 21, guinea pigs were sacrificed for RNA sequencing (RNA-seq) to screen for associated transcriptomic changes. Results The myopia model was successfully established in FD animals (control eye vs. FD eye, respectively: refraction at day 20, 0.97 ± 0.18 D vs. − 0.13 ± 0.38 D, F = 6.921, P = 0.02; AL difference between day 0 and day 21, 0.29 ± 0.04 mm vs. 0.45 ± 0.03 mm, F = 11.655, P = 0.004). Among the 3 different brimonidine administration methods, intravitreal injection was the most effective in slowing myopia progression, and 4 μg/μL was the most effective among the four different concentrations of brimonidine intravitreal injection tested. The AL and the refraction of the brimonidine intravitreal injection group was significantly shorter or more hyperopic than those of other 2 groups. Four μg/μL produced the smallest difference in AL and spherical equivalent difference values. FD treatment significantly increased the IOP. IOP was significantly lower at 1 day after intravitreal injections which was the lowest in FD eye of intravitreal injection of brimonidine. At day 21, gene expression analyses using RNA-seq showed upregulation of Col1a1 and Mmp2 expression levels by intravitreal brimonidine. Conclusions Among the 3 different administration methods, intravitreal injection of brimonidine was the most effective in slowing myopia progression in the FD guinea pig model. Intravitreal brimonidine at 4 μg/μL significantly reduced the development of FD myopia in guinea pigs. Expression levels of the Col1a1 and Mmp2 genes were significantly increased in the retinal tissues of the FD-Inj-Br group.

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The Peptide Vaccine Combined with Prior Immunization of a Conventional Diphtheria-Tetanus Toxoid Vaccine Induced AmyloidβBinding Antibodies on Cynomolgus Monkeys and Guinea Pigs

Journal of Immunology Research ◽

10.1155/2015/786501 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Akira Yano ◽

Kaori Ito ◽

Yoshikatsu Miwa ◽

Yoshito Kanazawa ◽

Akiko Chiba ◽

...

Keyword(s):

Immune Responses ◽

Tetanus Toxoid ◽

Guinea Pigs ◽

Peptide Vaccine ◽

Cell Epitope ◽

T Cell Epitope ◽

Peptide Vaccination ◽

Binding Profile ◽

Cynomolgus Monkeys ◽

The Brain

The reduction of brain amyloid beta (Aβ) peptides by anti-Aβantibodies is one of the possible therapies for Alzheimer’s disease. We previously reported that the Aβpeptide vaccine including the T-cell epitope of diphtheria-tetanus combined toxoid (DT) induced anti-Aβantibodies, and the prior immunization with conventional DT vaccine enhanced the immunogenicity of the peptide. Cynomolgus monkeys were given the peptide vaccine subcutaneously in combination with the prior DT vaccination. Vaccination with a similar regimen was also performed on guinea pigs. The peptide vaccine induced anti-Aβantibodies in cynomolgus monkeys and guinea pigs without chemical adjuvants, and excessive immune responses were not observed. Those antibodies could preferentially recognize Aβ40, and Aβ42compared to Aβfibrils. The levels of serum anti-Aβantibodies and plasma Aβpeptides increased in both animals and decreased the brain Aβ40level of guinea pigs. The peptide vaccine could induce a similar binding profile of anti-Aβantibodies in cynomolgus monkeys and guinea pigs. The peptide vaccination could be expected to reduce the brain Aβpeptides and their toxic effects via clearance of Aβpeptides by generated antibodies.

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Spatial-Temporal Distribution of the Freeze–Thaw Cycle of the Largest Lake (Qinghai Lake) in China Based on Machine Learning and MODIS from 2000 to 2020

Remote Sensing ◽

10.3390/rs13091695 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1695

Author(s):

Weixiao Han ◽

Chunlin Huang ◽

Juan Gu ◽

Jinliang Hou ◽

Ying Zhang

Keyword(s):

Machine Learning ◽

Land Surface ◽

Temporal Dynamics ◽

Temporal Distribution ◽

Ice Cover ◽

Qinghai Lake ◽

Gap Filling ◽

Thaw Cycle ◽

Break Up ◽

Ice Phenology

The lake ice phenology variations are vital for the land–surface–water cycle. Qinghai Lake is experiencing amplified warming under climate change. Based on the MODIS imagery, the spatio-temporal dynamics of the ice phenology of Qinghai Lake were analyzed using machine learning during the 2000/2001 to 2019/2020 ice season, and cloud gap-filling procedures were applied to reconstruct the result. The results showed that the overall accuracy of the water–ice classification by random forest and cloud gap-filling procedures was 98.36% and 92.56%, respectively. The annual spatial distribution of the freeze-up and break-up dates ranged primarily from DOY 330 to 397 and from DOY 70 to 116. Meanwhile, the decrease rates of freeze-up duration (DFU), full ice cover duration (DFI), and ice cover duration (DI) were 0.37, 0.34, and 0.13 days/yr., respectively, and the duration was shortened by 7.4, 6.8, and 2.6 days over the past 20 years. The increased rate of break-up duration (DBU) was 0.58 days/yr. and the duration was lengthened by 11.6 days. Furthermore, the increase in temperature resulted in an increase in precipitation after two years; the increase in precipitation resulted in the increase in DBU and decrease in DFU in corresponding years, and decreased DI and DFI after one year.

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THE PATHOLOGIC EFFECTS OF STREPTOCOCCI FROM CASES OF POLIOMYELITIS AND OTHER SOURCES

Journal of Experimental Medicine ◽

10.1084/jem.25.4.557 ◽

1917 ◽

Vol 25 (4) ◽

pp. 557-580 ◽

Cited By ~ 25

Author(s):

Carroll G. Bull

Keyword(s):

Spinal Cord ◽

Guinea Pigs ◽

The Other ◽

Laboratory Animals ◽

Histological Changes ◽

Other Hand ◽

Brain And Spinal Cord ◽

The Brain

Streptococci cultivated from the tonsils of thirty-two cases of poliomyelitis were used to inoculate various laboratory animals. In no case was a condition induced resembling poliomyelitis clinically or pathologically in guinea pigs, dogs, cats, rabbits, or monkeys. On the other hand, a considerable percentage of the rabbits and a smaller percentage of some of the other animals developed lesions due to streptococci. These lesions consisted of meningitis, meningo-encephalitis, abscess of the brain, arthritis, tenosynovitis, myositis, abscess of the kidney, endocarditis, pericarditis, and neuritis. No distinction in the character or frequency of the lesions could be determined between the streptococci derived from poliomyelitic patients and from other sources. Streptococci isolated from the poliomyelitic brain and spinal cord of monkeys which succumbed to inoculation with the filtered virus failed to induce in monkeys any paralysis or the characteristic histological changes of poliomyelitis. These streptococci are regarded as secondary bacterial invaders of the nervous organs. Monkeys which have recovered from infection with streptococci derived from cases of poliomyelitis are not protected from infection with the filtered virus, and their blood does not neutralize the filtered virus in vitro. We have failed to detect any etiologic or pathologic relationship between streptococci and epidemic poliomyelitis in man or true experimental poliomyelitis in the monkey.

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The brain timewise: how timing shapes and supports brain function

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2014.0170 ◽

2015 ◽

Vol 370 (1668) ◽

pp. 20140170 ◽

Cited By ~ 39

Author(s):

Riitta Hari ◽

Lauri Parkkonen

Keyword(s):

Human Brain ◽

Brain Imaging ◽

Brain Function ◽

Temporal Dynamics ◽

Generative Models ◽

Network Activity ◽

Brain Diseases ◽

Specific Information ◽

Non Invasive ◽

The Brain

We discuss the importance of timing in brain function: how temporal dynamics of the world has left its traces in the brain during evolution and how we can monitor the dynamics of the human brain with non-invasive measurements. Accurate timing is important for the interplay of neurons, neuronal circuitries, brain areas and human individuals. In the human brain, multiple temporal integration windows are hierarchically organized, with temporal scales ranging from microseconds to tens and hundreds of milliseconds for perceptual, motor and cognitive functions, and up to minutes, hours and even months for hormonal and mood changes. Accurate timing is impaired in several brain diseases. From the current repertoire of non-invasive brain imaging methods, only magnetoencephalography (MEG) and scalp electroencephalography (EEG) provide millisecond time-resolution; our focus in this paper is on MEG. Since the introduction of high-density whole-scalp MEG/EEG coverage in the 1990s, the instrumentation has not changed drastically; yet, novel data analyses are advancing the field rapidly by shifting the focus from the mere pinpointing of activity hotspots to seeking stimulus- or task-specific information and to characterizing functional networks. During the next decades, we can expect increased spatial resolution and accuracy of the time-resolved brain imaging and better understanding of brain function, especially its temporal constraints, with the development of novel instrumentation and finer-grained, physiologically inspired generative models of local and network activity. Merging both spatial and temporal information with increasing accuracy and carrying out recordings in naturalistic conditions, including social interaction, will bring much new information about human brain function.

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Heterogeneous activity level of jaw-closing and -opening muscles and its association with arousal levels during sleep in the guinea pig

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00205.2009 ◽

2010 ◽

Vol 298 (1) ◽

pp. R34-R42 ◽

Cited By ~ 10

Author(s):

Takafumi Kato ◽

Yuji Masuda ◽

Hayato Kanayama ◽

Norimasa Nakamura ◽

Atsushi Yoshida ◽

...

Keyword(s):

Heart Rate ◽

Eye Movement ◽

Rem Sleep ◽

Muscle Activity ◽

Guinea Pigs ◽

Nrem Sleep ◽

Activity Level ◽

Jaw Muscles ◽

High Activity Level ◽

Motor Activities

Exaggerated jaw motor activities during sleep are associated with muscle symptoms in the jaw-closing rather than the jaw-opening muscles. The intrinsic activity of antagonistic jaw muscles during sleep remains unknown. This study aims to assess the balance of muscle activity between masseter (MA) and digastric (DG) muscles during sleep in guinea pigs. Electroencephalogram (EEG), electroocculogram, and electromyograms (EMGs) of dorsal neck, MA, and DG muscles were recorded with video during sleep-wake cycles. These variables were quantified for each 10-s epoch. The magnitude of muscle activity during sleep in relation to mean EMG activity of total wakefulness was up to three times higher for MA muscle than for DG muscle for nonrapid eye movement (NREM) and rapid-eye-movement (REM) sleep. Although the activity level of the two jaw muscles fluctuated during sleep, the ratio of activity level for each epoch was not proportional. Epochs with a high activity level for each muscle were associated with a decrease in δEEG power and/or an increase in heart rate in NREM sleep. However, this association with heart rate and activity levels was not observed in REM sleep. These results suggest that in guinea pigs, the magnitude of muscle activity for antagonistic jaw muscles is heterogeneously modulated during sleep, characterized by a high activity level in the jaw-closing muscle. Fluctuations in the activity are influenced by transient arousal levels in NREM sleep but, in REM sleep, the distinct controls may contribute to the fluctuation. The above intrinsic characteristics could underlie the exaggeration of jaw motor activities during sleep (e.g., sleep bruxism).

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Vaccination with Recombinant Mycobacterium tuberculosis PknD Attenuates Bacterial Dissemination to the Brain in Guinea Pigs

PLoS ONE ◽

10.1371/journal.pone.0066310 ◽

2013 ◽

Vol 8 (6) ◽

pp. e66310 ◽

Cited By ~ 12

Author(s):

Ciaran Skerry ◽

Supriya Pokkali ◽

Michael Pinn ◽

Nicholas A. Be ◽

Jamie Harper ◽

...

Keyword(s):

Mycobacterium Tuberculosis ◽

Guinea Pigs ◽

Bacterial Dissemination ◽

The Brain

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Differential Contribution of Bacillus anthracis Toxins to Pathogenicity in Two Animal Models

Infection and Immunity ◽

10.1128/iai.00244-12 ◽

2012 ◽

Vol 80 (8) ◽

pp. 2623-2631 ◽

Cited By ~ 29

Author(s):

Haim Levy ◽

Shay Weiss ◽

Zeev Altboum ◽

Josef Schlomovitz ◽

Itai Glinert ◽

...

Keyword(s):

Animal Models ◽

Guinea Pigs ◽

Protective Antigen ◽

Comprehensive Evaluation ◽

Lethal Factor ◽

Rabbit Model ◽

Content Type ◽

Edema Factor ◽

Genes Encoding ◽

Guinea Pig Model

ABSTRACTThe virulence ofBacillus anthracis, the causative agent of anthrax, stems from its antiphagocytic capsule, encoded by pXO2, and the tripartite toxins encoded by pXO1. The accepted paradigm states that anthrax is both an invasive and toxinogenic disease and that the toxins play major roles in pathogenicity. We tested this assumption by a systematic study of mutants with combined deletions of thepag,lef, andcyagenes, encoding protective antigen (PA), lethal factor (LF), and edema factor (EF), respectively. The resulting seven mutants (single, double, and triple) were evaluated following subcutaneous (s.c.) and intranasal (i.n.) inoculation in rabbits and guinea pigs. In the rabbit model, virulence is completely dependent on the presence of PA. Any mutant bearing apagdeletion behaved like a pXO1-cured mutant, exhibiting complete loss of virulence with attenuation indices of over 2,500,000 or 1,250 in the s.c. or i.n. route of infection, respectively. In marked contrast, in guinea pigs, deletion ofpagor even of all three toxin components resulted in relatively moderate attenuation, whereas the pXO1-cured bacteria showed complete attenuation. The results indicate that a pXO1-encoded factor(s), other than the toxins, has a major contribution to the virulence mechanism ofB. anthracisin the guinea pig model. These unexpected toxin-dependent and toxin-independent manifestations of pathogenicity in different animal models emphasize the importance and need for a comprehensive evaluation ofB. anthracisvirulence in general and in particular for the design of relevant next-generation anthrax vaccines.

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Using the past to estimate sensory uncertainty

10.1101/589275 ◽

2019 ◽

Cited By ~ 1

Author(s):

Ulrik Beierholm ◽

Tim Rohe ◽

Ambra Ferrari ◽

Oliver Stegle ◽

Uta Noppeney

Keyword(s):

Temporal Dynamics ◽

Visual Signals ◽

Perceptual Inference ◽

Reliability Estimates ◽

Uncertainty Estimates ◽

Classical Models ◽

Past Experiences ◽

Combine Information ◽

Sensory Uncertainty ◽

The Brain

AbstractTo form the most reliable percept of the environment, the brain needs to represent sensory uncertainty. Current theories of perceptual inference assume that the brain computes sensory uncertainty instantaneously and independently for each stimulus.In a series of psychophysics experiments human observers localized auditory signals that were presented in synchrony with spatially disparate visual signals. Critically, the visual noise changed dynamically over time with or without intermittent jumps. Our results show that observers integrate audiovisual inputs weighted by sensory reliability estimates that combine information from past and current signals as predicted by an optimal Bayesian learner or approximate strategies of exponential discountingOur results challenge classical models of perceptual inference where sensory uncertainty estimates depend only on the current stimulus. They demonstrate that the brain capitalizes on the temporal dynamics of the external world and estimates sensory uncertainty by combining past experiences with new incoming sensory signals.

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