scholarly journals Cerebellar associative learning underlies skilled reach adaptation

2021 ◽  
Author(s):  
Dylan J Calame ◽  
Matthew I Becker ◽  
Abigail L Person
Keyword(s):  
Associative Learning ◽  
Closed Loop ◽  
Mossy Fiber ◽  
Late Phase ◽  
Population Level ◽  
Anticipatory Control ◽  
Neural Recordings ◽  
Optogenetic Stimulation ◽  
Partial Adaptation ◽  
Insight Into

Cerebellar output has been shown to enhance movement precision by scaling the decelerative phase of reaching movements in mice. We hypothesized that during reach, initial kinematics cue late-phase adjustments through cerebellar associative learning. We identify a population-level response in mouse PCs that scales inversely with reach velocity, suggesting a candidate mechanism for anticipatory control to target limb endpoint. We next interrogate how such a response is generated by combining high-density neural recordings with closed-loop optogenetic stimulation of cerebellar mossy fiber afferents originating in the pontine nuclei during reach, using perturbation schedules reminiscent of classic adaptation paradigms. We found that reach kinematics and PC electrophysiology adapt to position-locked mossy fiber perturbations and exhibit aftereffects when stimulation is removed. Surprisingly, we observed partial adaptation to position-randomized stimulation schedules but no opposing aftereffect. A model that recapitulated these findings provided novel insight into how the cerebellum deciphers cause-and-effect relationships to adapt.

scholarly journals Medical Sciences’ Students Responses During the Late Phase of the COVID-19 Pandemic in Iran: A Comprehensive Investigation of the Risk Perception and Information Exposure

2021 ◽  
Author(s):  
Mahan Shafie ◽  
Mahsa Mayeli ◽  
Hamed Hosseini ◽  
Mahnaz Ashoorkhani
Keyword(s):  
Risk Perception ◽  
Perceived Risk ◽  
Late Phase ◽  
Population Level ◽  
Sources Of Information ◽  
Medical Sciences ◽  
Online Questionnaire ◽  
Significant Difference ◽  
Information Exposure ◽  
Risk Patients

COVID-19 pandemic obligated applying population-level behavioral modifications to effectively prevent the spread of the disease. This necessitated investigating those measures that determine population behavior. Herein we have studied risk perception and information exposure that are among those determinants in Iran. 402 cases from medical sciences students were enrolled during the last week of September 2020. Using an online questionnaire, risk perception and sources of information about COVID-19 were investigated. Although most students considered COVID-19 preventable, merely a few considered the disease curable. A higher risk was perceived concerning the families compared to themselves. Moreover, most of them believed the prognosis good even in high-risk patients. Social media was the most informative source used; however, health professionals were considered the most reliable. The risk perception was equal between those diagnosed with COVID-19 or had a family member diagnosed compared to those without such exposure in most questions. Also, no significant difference was observed in risk perception between those students with serious underlying medical conditions and those without one regarding most items. Lastly, major and grade were the most significant demographic contributors to the risk perception. Moderate risk was perceived overall among the cases in which major and grade were the only remarkable demographic contributors. Unexpectedly, underlying medical history was not significantly correlated with the perceived risk. Lastly, previous COVID-19 exposure merely altered the curability and preventability perception.

scholarly journals Longer, More Active Commute, but Still not Very Active: Five-Year Physical Activity and Travel Behavior Change in a University Population

2019 ◽  
Vol 16 (13) ◽  
pp. 2420
Author(s):  
Lina Engelen ◽  
Erika Bohn-Goldbaum ◽  
Melanie Crane ◽  
Martin Mackey ◽  
Chris Rissel
Keyword(s):  
Physical Activity ◽  
Travel Behavior ◽  
Online Survey ◽  
Population Level ◽  
Active Travel ◽  
Physical Activity Monitoring ◽  
University Population ◽  
The University ◽  
Active Commute ◽  
Insight Into

Active travel can support the achievement of recommended levels of physical activity. Monitoring travel behavior of university students and staff provides a useful insight into patterns of regional travel and population level changes in physical activity. This study sought to evaluate current travel and physical activity behaviors in a university population and to determine whether these changed over time. An online survey of travel behavior and physical activity was conducted at the University of Sydney, Australia. The survey was actively promoted for three weeks prior to the release of the survey among staff and students, which asked about travel behavior on a specific day in September 2017. The survey questions were the same as those used in a similar online survey conducted across the University in 2012. In total, 4359 People completed the survey, representing 10.8% of staff and 4.1% of students. Approximately two thirds of survey respondents were students, in both the 2012 and 2017 surveys. Compared with 2012, there was an increase in active travel to the University in 2017 from increased walking and train travel. Compared to 2012, in 2017 there was an increase in average minutes walked by about nine minutes, and less time spent sitting. Trip lengths increased, with 68% of trips taking longer than 30 min in 2017. The amount of time spent in low–moderate levels physical activity increased between 2012 and 2017, potentially related to active travel behavior. Citywide changes towards a system-wide transport fare structure was the biggest change in the transport environment between the two surveys and may have contributed to increased train travel.

scholarly journals A novel device for real-time measurement and manipulation of licking behavior in head-fixed mice

2018 ◽  
Vol 120 (6) ◽  
pp. 2975-2987 ◽  
Author(s):  
Brice Williams ◽  
Anderson Speed ◽  
Bilal Haider
Keyword(s):  
Real Time ◽  
Neural Activity ◽  
Closed Loop ◽  
Neural Circuits ◽  
Neural Circuit ◽  
Visual Behavior ◽  
Sensory Stimuli ◽  
Neural Recordings ◽  
Control Signals ◽  
Sensory Motor

The mouse has become an influential model system for investigating the mammalian nervous system. Technologies in mice enable recording and manipulation of neural circuits during tasks where they respond to sensory stimuli by licking for liquid rewards. Precise monitoring of licking during these tasks provides an accessible metric of sensory-motor processing, particularly when combined with simultaneous neural recordings. There are several challenges in designing and implementing lick detectors during head-fixed neurophysiological experiments in mice. First, mice are small, and licking behaviors are easily perturbed or biased by large sensors. Second, neural recordings during licking are highly sensitive to electrical contact artifacts. Third, submillisecond lick detection latencies are required to generate control signals that manipulate neural activity at appropriate time scales. Here we designed, characterized, and implemented a contactless dual-port device that precisely measures directional licking in head-fixed mice performing visual behavior. We first determined the optimal characteristics of our detector through design iteration and then quantified device performance under ideal conditions. We then tested performance during head-fixed mouse behavior with simultaneous neural recordings in vivo. We finally demonstrate our device’s ability to detect directional licks and generate appropriate control signals in real time to rapidly suppress licking behavior via closed-loop inhibition of neural activity. Our dual-port detector is cost effective and easily replicable, and it should enable a wide variety of applications probing the neural circuit basis of sensory perception, motor action, and learning in normal and transgenic mouse models. NEW & NOTEWORTHY Mice readily learn tasks in which they respond to sensory cues by licking for liquid rewards; tasks that involve multiple licking responses allow study of neural circuits underlying decision making and sensory-motor integration. Here we design, characterize, and implement a novel dual-port lick detector that precisely measures directional licking in head-fixed mice performing visual behavior, enabling simultaneous neural recording and closed-loop manipulation of licking.

scholarly journals Real-Time PCR Investigation of Potential Vectors, Reservoirs, and Shedding Patterns of Feline Hemotropic Mycoplasmas

2007 ◽  
Vol 73 (12) ◽  
pp. 3798-3802 ◽  
Author(s):  
Barbara Willi ◽  
Felicitas S. Boretti ◽  
Marina L. Meli ◽  
Marco V. Bernasconi ◽  
Simona Casati ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Late Phase ◽  
Direct Transmission ◽  
Tissue Samples ◽  
Indirect Transmission ◽  
Rodent Population ◽  
Hemotropic Mycoplasma ◽  
Cat Fleas ◽  
Insight Into

ABSTRACT Three hemotropic mycoplasmas have been identified in pet cats: Mycoplasma haemofelis, “Candidatus Mycoplasma haemominutum,” and “Candidatus Mycoplasma turicensis.” The way in which these agents are transmitted is largely unknown. Thus, this study aimed to investigate fleas, ticks, and rodents as well as saliva and feces from infected cats for the presence of hemotropic mycoplasmas, to gain insight into potential transmission routes for these agents. DNA was extracted from arthropods and from rodent blood or tissue samples from Switzerland and from salivary and fecal swabs from two experimentally infected and six naturally infected cats. All samples were analyzed with real-time PCR, and some positive samples were confirmed by sequencing. Feline hemotropic mycoplasmas were detected in cat fleas and in a few Ixodes sp. and Rhipicephalus sp. ticks collected from animals but not in ticks collected from vegetation or from rodent samples, although the latter were frequently Mycoplasma coccoides PCR positive. When shedding patterns of feline hemotropic mycoplasmas were investigated, “Ca. Mycoplasma turicensis” DNA was detected in saliva and feces at the early but not at the late phase of infection. M. haemofelis and “Ca. Mycoplasma haemominutum” DNA was not amplified from saliva and feces of naturally infected cats, despite high hemotropic mycoplasma blood loads. Our results suggest that besides an ostensibly indirect transmission by fleas, direct transmission through saliva and feces at the early phase of infection could play a role in the epizootiology of feline hemotropic mycoplasmas. Neither the investigated tick nor the rodent population seems to represent a major reservoir for feline hemotropic mycoplasmas in Switzerland.

scholarly journals GluA4 enables associative memory formation by facilitating cerebellar expansion coding

2020 ◽  
Author(s):  
Katarzyna Kita ◽  
Catarina Albergaria ◽  
Ana S. Machado ◽  
Megan R. Carey ◽  
Martin Müller ◽  
...  
Keyword(s):  
Associative Learning ◽  
Associative Memory ◽  
Granule Cell ◽  
Ampa Receptors ◽  
Knockout Mice ◽  
Mossy Fiber ◽  
Eyeblink Conditioning ◽  
Memory Formation ◽  
Synaptic Excitation ◽  
Excitatory Neurotransmission

AbstractAMPA receptors (AMPARs) mediate excitatory neurotransmission in the CNS and their subunit composition determines synaptic efficacy. Whereas AMPAR subunits GluA1–GluA3 have been linked to particular forms of synaptic plasticity and learning, the functional role of GluA4 remains elusive. Here we used electrophysiological, computational and behavioral approaches to demonstrate a crucial function of GluA4 for synaptic excitation and associative memory formation in the cerebellum. Notably, GluA4-knockout mice had ∼80% reduced mossy fiber to granule cell synaptic transmission. The fidelity of granule cell spike output was markedly decreased despite attenuated tonic inhibition and increased NMDA receptor-mediated transmission. Computational modeling revealed that GluA4 facilitates pattern separation that is important for associative learning. On a behavioral level, while locomotor coordination was generally spared, GluA4-knockout mice failed to form associative memories during delay eyeblink conditioning. These results demonstrate an essential role for GluA4-containing AMPARs in cerebellar information processing and associative learning.

scholarly journals SkinnerTrax: high-throughput behavior-dependent optogenetic stimulation of Drosophila

2017 ◽  
Author(s):  
Ulrich Stern ◽  
Chung-Hui Yang
Keyword(s):  
High Throughput ◽  
Closed Loop ◽  
Optogenetic Stimulation ◽  
Cns Neurons ◽  
Highly Effective ◽  
Freely Moving ◽  
Stimulation Of

AbstractWhile red-shifted channelrhodopsin has been shown to be highly effective in activating CNS neurons in freely moving Drosophila, there were no existing high-throughput tools for closed-loop, behavior-dependent optogenetic stimulation of Drosophila. Here, we present SkinnerTrax to fill this void. SkinnerTrax stimulates individual flies promptly in response to their being at specific positions or performing specific actions. Importantly, SkinnerTrax was designed for and achieves significant throughput with simple and inexpensive components.

scholarly journals Data Resource: the Kent Integrated Dataset (KID)

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Dan Lewer ◽  
Tom Bourne ◽  
Abraham George ◽  
Gerrard Abi-Aad ◽  
Clint Taylor ◽  
...  
Keyword(s):  
Service Providers ◽  
Population Level ◽  
Community Health Services ◽  
System Level ◽  
Monthly Basis ◽  
Data Resource ◽  
Care Utilisation ◽  
General Practices ◽  
The Uk ◽  
Insight Into

IntroductionElectronic healthcare records from the UK are accessible to researchers via a number of platforms, but these platforms typically include data from a limited subset of health and care services. The Kent Integrated Dataset (KID) aims to provide insight into system-wide health and care utilisation for the whole population of Kent and Medway. MethodsThe KID uses pseudonymisation-at-source to link patient-level records from services including general practices, hospitals, community health services and social care. The design and governance of the dataset is led by local authorities, health commissioners and service providers. ResultsA population-level dataset has been developed, including data from April 2014 onwards. Data providers add new data on a monthly basis. The KID has been used to understand the costs associated with frailty, estimate the prevalence of rare conditions and compare the risk of non-elective hospitalisation between general practices. ConclusionThe KID is a unique and rich dataset available to researchers who are investigating a broad range of public health questions. It provides system-level insight into patient journeys and care utilisation and supports commissioning based on patient needs.

scholarly journals Mendelian randomization for studying the effects of perturbing drug targets

2021 ◽  
Vol 6 ◽  
pp. 16
Author(s):  
Dipender Gill ◽  
Marios K. Georgakis ◽  
Venexia M. Walker ◽  
A. Floriaan Schmidt ◽  
Apostolos Gkatzionis ◽  
...  
Keyword(s):  
Drug Targets ◽  
Mendelian Randomization ◽  
Population Level ◽  
Success Rates ◽  
Level Data ◽  
Large Databases ◽  
Natural Sequence Variation ◽  
Development Pipeline ◽  
Association Data ◽  
Insight Into

Drugs whose targets have genetic evidence to support efficacy and safety are more likely to be approved after clinical development. In this paper, we provide an overview of how natural sequence variation in the genes that encode drug targets can be used in Mendelian randomization analyses to offer insight into mechanism-based efficacy and adverse effects. Large databases of summary level genetic association data are increasingly available and can be leveraged to identify and validate variants that serve as proxies for drug target perturbation. As with all empirical research, Mendelian randomization has limitations including genetic confounding, its consideration of lifelong effects, and issues related to heterogeneity across different tissues and populations. When appropriately applied, Mendelian randomization provides a useful empirical framework for using population level data to improve the success rates of the drug development pipeline.

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