Behavioral Phenotyping of Juvenile Long-Evans and Sprague-Dawley Rats: Implications for Preclinical Models of Autism Spectrum Disorders.

The laboratory rat is emerging as an attractive preclinical animal model of autism spectrum disorder (ASD), allowing investigators to explore genetic, environmental and pharmacological manipulations in a species exhibiting complex, reciprocal social behavior. The present study was carried out to compare two commonly used strains of laboratory rats, Sprague-Dawley (SD) and Long-Evans (LE), between the ages of postnatal day (PND) 26-56 using high-throughput behavioral phenotyping tools commonly used in mouse models of ASD that we have adapted for use in rats. We detected few differences between young SD and LE strains on standard assays of exploration, sensorimotor gating, anxiety, repetitive behaviors, and learning. Both SD and LE strains also demonstrated sociability in the 3-chamber social approach test as indexed by spending more time in the social chamber with a constrained age/strain/sex matched novel partner than in an identical chamber without a partner. Pronounced differences between the two strains were, however, detected when the rats were allowed to freely interact with a novel partner in the social dyad paradigm. The SD rats in this particular testing paradigm engaged in play more frequently and for longer durations than the LE rats at both juvenile and young adult developmental time points. Results from this study that are particularly relevant for developing preclinical ASD models in rats are threefold: (i) commonly utilized strains exhibit unique patterns of social interactions, including strain-specific play behaviors, (ii) the testing environment may profoundly influence the expression of strain-specific social behavior and (iii) simple, automated measures of sociability may not capture the complexities of rat social interactions

Priming to promote fluent motor skill execution: Exploring attentional demands

The effect of priming on the speed and accuracy of skilled performance and on a probe-reaction time task designed to measure residual attentional capacity, was assessed. Twenty-four skilled soccer players completed a dribbling task under three prime conditions (fluency, skill-focus, and neutral) and a control condition. Results revealed changes in trial completion time and secondary task performance in line with successfully priming autonomous and skill-focused attention. Retention test data for task completion time and probe-reaction time indicated a linear decrease in the priming effect such that the effect was nonsignificant after 30 min. Results provide further support for the efficacy of priming and provide the first evidence of concurrent changes in attentional demands, consistent with promoting or disrupting automatic skill execution

Behavioral outcome measures to improve experimental stroke research

Functional recovery after an experimental stroke can be assessed by multiple behavioural tests, however, there is no consensus about which test to use in long-term stroke recovery studies or whether the tests are affected by stroke surgery, post-operative care or behavioural compensation due to repeated testing. This review describes the tests most commonly used to assess motor and sensorimotor function, cognition and mood in stroke animals. Although it is difficult to predict the direction of future research, it may be possible to prevent false-positive results by selecting an appropriate task or a battery of tasks. It is also expected that the upcoming stroke recovery recommendations and the improved dialogue between academy, industry and healthcare professionals will further promote translational success

Sensorimotor Behavioral Tests for Use in a Juvenile Rat Model of Traumatic Brain Injury: Assessment of Sex Differences

Modeling juvenile traumatic brain injury (TBI) in rodents presents several unique challenges compared to adult TBI, one of which is selecting appropriate sensorimotor behavioral tasks that enable the assessment of the extent of injury and recovery over time in developing animals. To address this challenge, we performed a comparison of common sensorimotor tests in Long-Evans rats of various sizes and developmental stages (postnatal days 16–45, 35–190 g). Tests were compared and selected for their developmental appropriateness, scalability for growth, pre-training requirements, and throughput capability. Sex differences in response to TBI were also assessed. Grid walk, automated gait analysis, rotarod, beam walk, spontaneous forelimb elevation test, and measurement of motor activity using the force-plate actometer were evaluated. Grid walk, gait analysis, and rotarod failed to meet one or more of the evaluation criteria. Beam walk, spontaneous forelimb elevation test, and measurement of motor activity using the force-plate actometer satisfied all criteria and were capable of detecting motor abnormalities in rats subjected to controlled cortical impact on postnatal day 17. No sex differences were detected in the acute effects of TBI or functional recovery during the 28 days after injury using these tests. This demonstrates the utility of these tests for the evaluation of sensorimotor function in studies using rat models of pediatric TBI, and suggest that pre-pubertal males and females respond similarly to TBI with respect to sensorimotor outcomes

Brain-Switches for Asynchronous Brain−Computer Interfaces: A Systematic Review

A brain–computer interface (BCI) has been extensively studied to develop a novel communication system for disabled people using their brain activities. An asynchronous BCI system is more realistic and practical than a synchronous BCI system, in that, BCI commands can be generated whenever the user wants. However, the relatively low performance of an asynchronous BCI system is problematic because redundant BCI commands are required to correct false-positive operations. To significantly reduce the number of false-positive operations of an asynchronous BCI system, a two-step approach has been proposed using a brain-switch that first determines whether the user wants to use an asynchronous BCI system before the operation of the asynchronous BCI system. This study presents a systematic review of the state-of-the-art brain-switch techniques and future research directions. To this end, we reviewed brain-switch research articles published from 2000 to 2019 in terms of their (a) neuroimaging modality, (b) paradigm, (c) operation algorithm, and (d) performance

Enhanced tracking system based on micro inertial measurements unit to measure sensorimotor responses in pigeons

The ability to orientate and navigate is critically important for the survival of all migratory birds and other animals. Progress in understanding the mechanisms underlying these capabilities and, in particular, the importance of a sensitivity to the Earth’s magnetic field has, thus far, been constrained by the limited number of techniques available for the analysis of often complex behavioural responses. Methods used to track the movements of animals, such as birds, have varied depending on the degree of accuracy required. Most conventional approaches involve the use of a camera for recording and then measuring an animal's head movements in response to a variety of external stimuli, such as changes in magnetic fields. However, video tracking analysis (VTA) will generally only provide a 2D tracking of head angle. Moreover, such a video analysis can only provide information about movements when the head is in view of the camera. In order to overcome these limitations, the novel invention reported here utilises a lightweight (<10g) Inertial Measurement Unit (IMU), positioned on the head of a homing pigeon, which contains a sensor with tri-axial orthogonal accelerometers, gyroscopes, and magnetometers. This highly compact (20.3×12.7×3 mm) system, can be programmed and calibrated to provide measurements of the three rotational angles (roll, pitch and yaw) simultaneously, eliminating any drift, i.e. the movement of the pigeon's head is determined by detecting and estimating the directions of motion at all angles (even those outside the defined areas of tracking). Using an existing VTA approach as a baseline for comparison, it is demonstrated IMU technology can comprehensively track a pigeon’s normal head movements with greater precision and in all 3 axes

Impaired decisional impulsivity in pathological videogamers

Abstract Background Pathological gaming is an emerging and poorly understood problem. Impulsivity is commonly impaired in disorders of behavioural and substance addiction, hence we sought to systematically investigate the different subtypes of decisional and motor impulsivity in a well-defined pathological gaming cohort. Methods Fifty-two pathological gaming subjects and age-, gender- and IQ-matched healthy volunteers were tested on decisional impulsivity (Information Sampling Task testing reflection impulsivity and delay discounting questionnaire testing impulsive choice), and motor impulsivity (Stop Signal Task testing motor response inhibition, and the premature responding task). We used stringent diagnostic criteria highlighting functional impairment. Results In the Information Sampling Task, pathological gaming participants sampled less evidence prior to making a decision and scored fewer points compared with healthy volunteers. Gaming severity was also negatively correlated with evidence gathered and positively correlated with sampling error and points acquired. In the delay discounting task, pathological gamers made more impulsive choices, preferring smaller immediate over larger delayed rewards. Pathological gamers made more premature responses related to comorbid nicotine use. Greater number of hours played also correlated with a Motivational Index. Greater frequency of role playing games was associated with impaired motor response inhibition and strategy games with faster Go reaction time. Conclusions We show that pathological gaming is associated with impaired decisional impulsivity with negative consequences in task performance. Decisional impulsivity may be a potential target in therapeutic management