Automated system for training and assessing reaching and grasping behaviors in rodents.

BACKGROUND: Reaching, grasping, and pulling behaviors are studied across species to investigate motor control and problem solving. String pulling is a distinct reaching and grasping behavior that is rapidly learned, requires bimanual coordination, is ethologically grounded, and has been applied across species and disease conditions. NEW METHOD: Here we describe the PANDA system (Pulling And Neural Data Analysis), a hardware and software system that integrates a continuous string loop connected to a rotary encoder, feeder, microcontroller, high-speed camera, and analysis software for the assessment and training of reaching, grasping, and pulling behaviors and synchronization with neural data. RESULTS: We demonstrate this system in rats implanted with electrodes in motor cortex and hippocampus and show how it can be used to assess relationships between reaching, pulling, and grasping movements and single-unit and local-field activity. Furthermore, we found that automating the shaping procedure significantly improved performance over manual training, with rats pulling > 100 m during a 15-minute session. COMPARISON WITH EXISTING METHODS: String-pulling is typically shaped by tying food reward to the string and visually scoring behavior. The system described here automates training, streamlines video assessment with deep learning, and automatically segments reaching movements into distinct reach/pull phases. No system, to our knowledge, exists for the automated shaping and assessment of this behavior. CONCLUSIONS: This system will be of general use to researchers investigating motor control, motivation, sensorimotor integration, and motor disorders such as Parkinson's disease and stroke.

Automated system for training and assessing string-pulling behaviors in rodents.

String-pulling tasks have been used for centuries to study coordinated bimanual motor behavior and problem solving. String pulling is rapidly learned, ethologically grounded, and has been applied to many species and disease conditions. Typically, training of string-pulling behaviors is achieved through manual shaping and baiting. Furthermore, behavioral assessment of reaching, grasping, and pulling is often performed through labor intensive manual video scoring. No system, to our knowledge, currently exists for the automated shaping and assessment of string-pulling behaviors. Here we describe the PANDA system (Pulling And Neural Data Analysis), an inexpensive hardware and software system that utilizes a continuous string loop connected to a rotary encoder, feeder, microcontroller, high-speed camera, and analysis software for assessment and training of string-pulling behaviors and synchronization with neural recording data. We demonstrate this system in unimplanted rats and rats implanted with electrodes in motor cortex and hippocampus and show how the PANDA system can be used to assess relationships between paw movements and single-unit and local-field activity. We also found that automating the shaping procedure significantly improved overall performance, with rats regularly pulling >100 meters during a 15-minute session. In conclusion, the PANDA system will be of general use to researchers investigating motor control, motivation, and motor disorders such as Parkinson's disease, Huntington's disease, and stroke. It will also support the investigation of neural mechanisms involved in sensorimotor integration.

Marijuana use among adolescent multiple tobacco product users and unique risks of dual tobacco and marijuana use.

BACKGROUND: Adolescence is a peak time for uptake of both tobacco and marijuana (dual use). This study aimed to identify clusters of lifetime tobacco and marijuana use patterns and associated risk factors, and to determine whether dual tobacco and marijuana use is uniquely associated with greater risk than use of either tobacco or marijuana alone. METHOD: High school students participated in a survey during Fall 2014 (N = 976; 68% Hispanic; 57% parental education < high school). Items from national youth surveys were used to measure lifetime and current use of tobacco products, marijuana, alcohol, drug use, and other risk behaviors, and literature-based surveys were used to measure psychological constructs. RESULTS: Latent Class Analysis identified three clusters of lifetime tobacco use patterns (no tobacco, one or two products, and more than two products), each with a correspondingly distinct profile of risk behaviors; risk escalated with use of more tobacco products. Multinomial modeling characterized personal, environmental, and behavioral correlates of dual lifetime tobacco and marijuana use, including lower parental monitoring, lower grades, higher guilt, higher lifetime alcohol and drug use, and more substance use by friends, in reference to single lifetime use of either tobacco or marijuana. CONCLUSION: Broader use of tobacco (i.e., more products) was associated with numerous risk factors. Dual lifetime use of tobacco and marijuana was associated with numerous risks compared to single use of either tobacco or marijuana. Longitudinal work is needed to understand temporal relationships between risk variables to determine optimal timing for interventions to reduce harmful behaviors.

Internet-based Advertising Claims and Consumer Reasons for Using Electronic Cigarettes by Device Type in the US.

OBJECTIVES: Important differences exist between closed-system and open-system e-cigarettes, but it is unknown whether online companies are marketing these devices differently and whether consumer reasons for using e-cigarettes vary by device type. This paper compares Internet-based advertising claims of closed- versus open-system products, and evaluates US consumers' reasons for using closed- versus open-system e-cigarettes. METHODS: Internet sites selling exclusively closed (N = 130) or open (N = 129) e-cigarettes in December 2013-January 2014 were coded for advertising claims. Current users (≥18 years old) of exclusively closed or open e-cigarettes (N = 860) in a nationally representative online survey in February-March 2014 provided their main reason for using e-cigarettes. RESULTS: Internet sites that exclusively sold closed-system e-cigarettes were more likely to make cigarette-related claims such as e-cigarettes being healthier and cheaper than cigarettes (ps < .0001) compared to sites selling open systems. Many sites implied their products could help smokers quit. Exclusive users of both systems endorsed cessation as their top reason. Closed-system users were more likely to report their reason as "use where smoking is banned." CONCLUSIONS: Although promotion of e-cigarettes as cessation aids is prohibited, consumers of both systems endorsed smoking cessation as their top reason for using e-cigarettes.