Quantitation of rodent catalepsy by a computer-imaging technique

Development and Validation of an Automated Video Tracking Model for Stabled Horses

Simple Summary

Although there are some methods to detect pain in horses, because of bias and time-consumption, those methods are practically challenging. However, in recent years rapidly developed automated tracking methods have proven that computer-based behaviour monitoring is more reliable in many animal species. That is why in this study we aimed to investigate an automated video tracking model for horses in a clinical context. The findings will help to develop the automated detection of daily activity, to meet the ultimate objective of objectively assessing the pain and wellbeing of horses. An initial analysis of the obtained data offers the opportunity to construct an algorithm to track automatically behaviour patterns of horses.

Abstract

Changes in behaviour are often caused by painful conditions. Therefore, the assessment of behaviour is important for the recognition of pain, but also for the assessment of quality of life. Automated detection of movement and the behaviour of a horse in the box stall should represent a significant advancement. In this study, videos of horses in an animal hospital were recorded using an action camera and a time-lapse mode. These videos were processed using the convolutional neural network Loopy for automated prediction of body parts. Development of the model was carried out in several steps, including annotation of the key points, training of the network to generate the model and checking the model for its accuracy. The key points nose, withers and tail are detected with a sensitivity of more than 80% and an error rate between 2 and 7%, depending on the key point. By means of a case study, the possibility of further analysis with the acquired data was investigated. The results will significantly improve the pain recognition of horses and will help to develop algorithms for the automated recognition of behaviour using machine learning.

SwarmSight: Measuring the temporal progression of animal group activity levels from natural-scene and laboratory videos

We describe SwarmSight (available at https://github.com/justasb/SwarmSight ), a novel, open-source, Microsoft Windows software tool for quantitative assessment of the temporal progression of animal group activity levels from recorded videos. The tool utilizes a background subtraction machine vision algorithm and provides an activity metric that can be used to quantitatively assess and compare animal group behavior. Here we demonstrate the tool's utility by analyzing defensive bee behavior as modulated by alarm pheromones, wild-bird feeding onset and interruption, and cockroach nest-finding activity. Although more sophisticated, commercial software packages are available, SwarmSight provides a low-cost, open-source, and easy-to-use alternative that is suitable for a wide range of users, including minimally trained research technicians and behavioral science undergraduate students in classroom laboratory settings.

Comparing the EthoVision 2.3 system and a new computerized multitracking prototype system to measure the swimming behavior in fry fish

Coming from the framework of unmarked fry tracking, we compared the capacities, advantages, and disadvantages of two recent video tracking systems: EthoVision 2.3 and a new prototype of multitracking. The EthoVision system has proved to be impressive for tracking a fry using the detection by gray scaling. Detection by subtraction has given less accurate results. Our video multitracking system is able to detect and track more than 100 unmarked fish by gray scaling technique. It permits an analysis at the group level as well as at the individual level. The multitracking program is able to attribute a number to each fish and to follow each one for the whole duration of the track. Our system permits the analysis of the movement of each individual, even if the trajectories of two fish cross each other. This is possible thanks to t hetheoretical estimation of th e trajectory of each fish, which can becompared with the real trajectory (analysis with feedback). However, the period of the track is limited for our system (about 1 min), whereas EthoVision is able to track for numerous hours. In spite of these limitations, these two systems allow an almost continuous automatic sampling of the movement behaviors during the track.

A novel automated rat catalepsy bar test system based on a RISC microcontroller

Catalepsy tests performed in rodents treated with drugs that interfere with dopaminergic transmission have been widely used for the screening of drugs with therapeutic potential in the treatment of Parkinson's disease. The basic method for measuring catalepsy intensity is the "standard" bar test. We present here an easy to use microcontroller-based automatic system for recording bar test experiments. The design is simple, compact, and has a low cost. Recording intervals and total experimental time can be programmed within a wide range of values. The resulting catalepsy times are stored, and up to five simultaneous experiments can be recorded. A standard personal computer interface is included. The automated system also permits the elimination of human error associated with factors such as fatigue, distraction, and data transcription, occurring during manual recording. Furthermore, a uniform criterion for timing the cataleptic condition can be achieved. Correlation values between the results obtained with the automated system and those reported by two independent observers ranged between 0.88 and 0.99 (P<0.0001; three treatments, nine animals, 144 catalepsy time measurements).

The EthoVision video tracking system--a tool for behavioral phenotyping of transgenic mice

Video tracking systems enable behavior to be studied in a reliable and consistent way, and over longer time periods than if they are manually recorded. The system takes an analog video signal, digitizes each frame, and analyses the resultant pixels to determine the location of the tracked animals (as well as other data). Calculations are performed on a series of frames to derive a set of quantitative descriptors of the animal's movement. EthoVision (from Noldus Information Technology) is a specific example of such a system, and its functionality that is particularly relevant to transgenic mice studies is described. Key practical aspects of using the EthoVision system are also outlined, including tips about lighting, marking animals, the arena size, and sample rate. Four case studies are presented, illustrating various aspects of the system: (1) The effects of disabling the Munc 18-1 gene were clearly shown using the straightforward measure of how long the mice took to enter a zone in an open field. (2) Differences in exploratory behavior between short and long attack latency mice strains were quantified by measuring the time spent in inner and outer zones of an open field. (3) Mice with hypomorphic CREB alleles were shown to perform less well in a water maze, but this was only clear when a range of different variables were calculated from their tracks. (4) Mice with the trkB receptor knocked out in the forebrain also performed poorly in a water maze, and it was immediately apparent from examining plots of the tracks that this was due to thigmotaxis. Some of the latest technological developments and possible future directions for video tracking systems are briefly discussed.

EthoVision: a versatile video tracking system for automation of behavioral experiments

The need for automating behavioral observations and the evolution of systems developed for that purpose is outlined. Video tracking systems enable researchers to study behavior in a reliable and consistent way and over longer time periods than if they were using manual recording. To overcome limitations of currently available systems, we have designed EthoVision, an integrated system for automatic recording of activity, movement, and interactions of animals. The EthoVision software is presented, highlighting some key features that separate EthoVision from other systems: easy file management, independent variable definition, flexible arena and zone design, several methods of data acquisition allowing identification and tracking of multiple animals in multiple arenas, and tools for visualization of the tracks and calculation of a range of analysis parameters. A review of studies using EthoVision is presented, demonstrating the system's use in a wide variety of applications. Possible future directions for development are discussed.

Cannabinoid withdrawal is dependent upon PKA activation in the cerebellum

Region-specific up-regulation of the cyclic AMP pathway is considered an important molecular mechanism in the origin of the somatic manifestations of the withdrawal syndrome to known drugs of abuse. Nevertheless, the existence of a withdrawal syndrome after prolonged cannabinoid administration has long been a controversial issue. Recent studies, in different species, have shown that withdrawal to prolonged cannabinoid exposure precipitated by the cannabinoid antagonist SR141716A is characterized by physical signs underlying impairment of motor coordination. Interestingly, cannabinoid withdrawal is accompanied by an increase of adenylyl cyclase activity in the cerebellum. Here, we investigate the functional role of the cyclic AMP pathway in the cerebellum in the establishment of cannabinoid withdrawal. We show that after SR141716A precipitation of cannabinoid withdrawal, basal and calcium-calmodulin-stimulated adenylyl cyclase activities as well as active PKA in the cerebellum increase in a transient manner with a temporal profile which matches that of the somatic expression of abstinence. Selectively blocking the up-regulation of the cyclic AMP pathway in the cerebellum, by microinfusing the cyclic AMP blocker Rp-8Br-cAMPS in this region, markedly reduced both PKA activation and the somatic expression of cannabinoid withdrawal. Our results (i) directly link the behavioural manifestations of cannabinoid withdrawal with the up-regulation of the cyclic AMP pathway in the cerebellum, pointing towards common molecular adaptive mechanisms for dependence and withdrawal to most drugs of abuse; (ii) suggest a particular role for the cerebellum as a major neurobiological substrate for cannabinoid withdrawal.

The selective cannabinoid antagonist SR 141716A blocks cannabinoid-induced antinociception in rats

The purported CB1 cannabinoid antagonist SR 141716A has proven to be a useful tool in the investigation of cannabinoid pharmacology. This antagonist was employed in the present study to investigate the antinociceptive and cataleptic effects of cannabinoids after either systemic or intracerebroventricular (ICV) administration. The antinociceptive potency of systemically administered delta 9-tetrahydrocannabinol (delta 9-THC) was decreased 18-fold by SR 141716A, from an ED50 value of 0.3-5.1 mg/kg. Similarly, it completely blocked the antinociceptive effects of delta 9-THC and CP 55,940, a potent bicyclic cannabinoid, after ICV administration. In addition, it prevented cannabinoid-induced catalepsy when given by either route of administration. In contrast, SR 141716A failed to antagonize the antinociceptive effects of morphine, indicating its selectivity for cannabinoid receptors. These findings indicate that the antinociceptive and cataleptic effects of delta 9-THC and CP 55,940 are mediated through CB1 cannabinoid receptors.

A quantification of goldfish behavior by an image processing system

We developed a computer-image processing system to quantitatively score the goldfish behavior. The system was composed of two CCD cameras, set in the upper and side directions of a water tank, two graphics I/O boards (video interface) and an IBM PC/AT compatible computer. From the top and side views through the two CCD cameras, 2-dimensional or 3-dimensional positional coordinates of fish freely moving in an aquarium were acquired over a long period (60 min). A positional distribution histogram of the goldfish was made by measuring the number of coordinates. Goldfish have a tendency to move at the circumference and bottom of a water tank. The velocity of moving goldfish was calculated from the time and distance. The average velocity of goldfish was in the range of 6-36 mm/s. A directional histogram (go straight and turn right or left) of a moving goldfish in an aquarium was made to measure an angle formed by two vectors, which were defined as three (middle to terminal against initial to middle) points in a unitary length (50 mm) of the path of goldfish. Three directions (go straight, right turn and left turn) were quantified as a percentage (59 +/- 12%, 20 +/- 4% and 20 +/- 4%, respectively) of a 1-h-event of moving goldfish. This image processing system thus can make an easy and quantifiable behavioral analysis of moving goldfish.

Systemic or intrahippocampal cannabinoid administration impairs spatial memory in rats

The purpose of the present study was to investigate the disruptive effects of cannabinoids on working memory as assessed in the eight-arm radial-maze. Systemic administration of delta 9-THC, WIN-55,212-2, and CP-55,940 increased the number of errors committed in the radial-maze. CP-55,940 was the most potent cannabinoid in impairing memory (ED50 = 0.13 mg/kg). delta 9-THC and WIN-55,212-2 disrupted maze-choice accuracy at equipotent doses (ED50 values = 2.1 and 2.2 mg/kg, respectively). In addition, systemic administration of each of these agents retarded completion time. Whereas the doses of delta 9-THC and CP-55,940 required to retard maze performance were higher than those needed to increase error numbers, WIN-55,212-2 was equipotent in both of these measures. On the other hand, neither anandamide, the putative endogenous cannabinoid ligand, nor cannabidiol, an inactive naturally occurring cannabinoid, had any apparent effects on memory. A second aim of this study was to elucidate the neuroanatomical substrates mediating the disruptive effects of cannabinoids on memory. Intrahippocampal injections of CP-55,940 impaired maze performance in a dose-dependent manner (ED50 = 8 micrograms/rat), but did not retard the amount of time required to complete the maze. The effects of intrahippocampal CP-55,940 were apparently specific to cognition because no other cannabinoid pharmacological effects (e.g., antinociception, hypothermia, and catalepsy) were detected. This dissociation between choice accuracy in the radial-maze and other cannabinoid pharmacological effects suggests that the working memory deficits produced by cannabinoids may be mediated by cannabinoid receptors in the hippocampus.