An automated Y-maze based on a reduced instruction set computer (RISC) microcontroller for the assessment of continuous spontaneous alternation in rats.

Continuous spontaneous alternation behavior (SAB) in a Y-maze is used for evaluating working memory in rodents. Here, the design of an automated Y-maze equipped with three infrared optocouplers per arm, and commanded by a reduced instruction set computer (RISC) microcontroller is described. The software was devised for recording only true entries and exits to the arms. Experimental settings are programmed via a keyboard with three buttons and a display. The sequence of arm entries and the time spent in each arm and the neutral zone (NZ) are saved as a text file in a non-volatile memory for later transfer to a USB flash memory. Data files are analyzed with a program developed under LabVIEW® environment, and the results are exported to an Excel® spreadsheet file. Variables measured are: latency to exit the starting arm, sequence and number of arm entries, number of alternations, alternation percentage, and cumulative times spent in each arm and NZ. The automated Y-maze accurately detected the SAB decrease produced in rats by the muscarinic antagonist trihexyphenidyl, and its reversal by caffeine, having 100 % concordance with the alternation percentages calculated by two trained observers who independently watched videos of the same experiments. Although the values of time spent in the arms and NZ measured by the automated system had small discrepancies with those calculated by the observers, Bland-Altman analysis showed 95 % concordance in three pairs of comparisons, while in one it was 90 %, indicating that this system is a reliable and inexpensive alternative for the study of continuous SAB in rodents.

Low-cost USB interface for operant research using Arduino and Visual Basic.

This note describes the design of a low-cost interface using Arduino microcontroller boards and Visual Basic programming for operant conditioning research. The board executes one program in Arduino programming language that polls the state of the inputs and generates outputs in an operant chamber. This program communicates through a USB port with another program written in Visual Basic 2010 Express Edition running on a laptop, desktop, netbook computer, or even a tablet equipped with Windows operating system. The Visual Basic program controls schedules of reinforcement and records real-time data. A single Arduino board can be used to control a total of 52 inputs/output lines, and multiple Arduino boards can be used to control multiple operant chambers. An external power supply and a series of micro relays are required to control 28-V DC devices commonly used in operant chambers. Instructions for downloading and using the programs to generate simple and concurrent schedules of reinforcement are provided. Testing suggests that the interface is reliable, accurate, and could serve as an inexpensive alternative to commercial equipment.

Evaluation of the potential of antipsychotic agents to induce catalepsy in rats: assessment of a new, commercially available, semi-automated instrument.

Haloperidol induced catalepsy was determined using the classic bar test and a new MED Associates Catalepsy Test Chamber instrument. The dose that produced an adverse effect in 50% of rats (AED50) for haloperidol was calculated using the instrument data as 0.29 mg/kg. Hand scoring of the video recordings gave AED50 values of 0.30 and 0.31 mg/kg, both well within the 95% CL of the instrument data. Clozapine was also evaluated and catalepsy was not detected up to 40 mg/kg. No significant difference was found between the instrument and hand scoring data. The instrument was useful for testing haloperidol and clozapine, relieving much of the tedium and variability experienced without its use. It was especially valuable at measuring shorter time periods, where the researcher cannot react as quickly. Finally, olanzapine was also evaluated. However, clenched forepaws and hind paws prevented the use of the instrument alone at higher doses. A backup stopwatch was used for the bar test in these cases. Some of the advantages and limitations are discussed. Results are also compared to the crossed-legs position (CLP) test for all three antipsychotics. While haloperidol gave similar results at all concentrations tested, clozapine deviated significantly at the highest dose (40 mg/kg) displaying catalepsy in the CLP test but not in the bar test. Olanzapine displayed catalepsy in rats significantly different from vehicle at 40 mg/kg in both the bar and CLP tests. However, the CLP test may be more suited to compounds with gripping problems which prevent the consistent grasping of the bar. Overall, the instrument was found to be a useful aid in conducting the bar test for catalepsy. The CLP test was found to complement the bar test under certain conditions and could provide additional data that might be missed by the bar test for compounds producing grasping problems.

Development and validation of an automated system for detection and assessment of scratching in the rodent.

Pruritus, the sensation of itch, which evokes reflex scratching behavior, has a diverse etiology. Because of its clinical significance, mechanisms of pruriception are an important topic. In the present work we describe and validate a paw motion detector (PMD) system. The system employs a small removable metal band placed on one hind paw that provides a signal indicative of paw movement through perturbation of an electromagnetic (EM) field. C57Bl/6 mice were fitted with a unilateral hind paw band and adapted to testing cylinders equipped with EM signal emission and detection. The following observations were made: (1) in mice, unilateral SQ injection of 48/80 into the dorsolateral aspect of the neck evoked periodic high frequency bursts of scratching at the injected site with the ipsilateral (banded) but not the contralateral (not banded) hind paw. (2) Cross correlation between PMD and human observer counts after SQ 48/80 using the specified computational algorithm revealed a highly significant correlation. (3) SQ histamine and 48/80 over a 1hour interval produced dose dependent scratching, which diphenhydramine dose dependently reversed. Chloroquine scratching displayed an inverse u-shaped dose response curve, which was insensitive to diphenhydramine. (4) SQ 48/80 at intervals over 28 days showed no change in the scratching response within the same cohort of mice. (5) Power analysis showed 40% changes in scratching activity could be detected at the p<0.05 level with groups of 4 mice. These observations indicate that the system described can efficiently define the actions and pharmacology of pruritogenic agents.

Arduino: a low-cost multipurpose lab equipment.

Typical experiments in psychological and neurophysiological settings often require the accurate control of multiple input and output signals. These signals are often generated or recorded via computer software and/or external dedicated hardware. Dedicated hardware is usually very expensive and requires additional software to control its behavior. In the present article, I present some accuracy tests on a low-cost and open-source I/O board (Arduino family) that may be useful in many lab environments. One of the strengths of Arduinos is the possibility they afford to load the experimental script on the board's memory and let it run without interfacing with computers or external software, thus granting complete independence, portability, and accuracy. Furthermore, a large community has arisen around the Arduino idea and offers many hardware add-ons and hundreds of free scripts for different projects. Accuracy tests show that Arduino boards may be an inexpensive tool for many psychological and neurophysiological labs.

Affect 4.0: a free software package for implementing psychological and psychophysiological experiments.

We describe Affect 4.0, a user-friendly software package for implementing psychological and psychophysiological experiments. Affect 4.0 can be used to present visual, acoustic, and/or tactile stimuli in highly complex (i.e., semirandomized and response-contingent) sequences. Affect 4.0 is capable of registering response latencies and analog behavioral input with millisecond accuracy. Affect 4.0 is available free of charge.

An inexpensive infrared detector to verify the delivery of food pellets.

The reproducibility of experimental outcomes depends on consistent control of independent variables. In food-maintained operant performance, it is of utmost importance that the quantity of food delivered is reliable. To that end, some commercial food pellet dispensers have add-on attachments to sense the delivery of pellets. Not all companies, however, offer such add-ons. Aside from availability, cost and temporary reduction in throughput may be a problem for smaller labs. The present paper outlines our recent development of a simple, inexpensive infrared device to detect and confirm the delivery of pellets. The in-line construction of the detector routes the falling pellet through a barrel so that it passes between an infrared emitter and receiver. The circuitry was designed to be compatible with all commercially available behavioral measurement systems, and so may be retrofit to any existing system. Our tests with the detector so far have shown that it is 100% accurate in detecting pellet delivery. The individual unit cost is approximately 25 dollars. The low cost and versatility of the device offer an easy method to ensure the integrity of food delivery in operant settings.

EMOTLAB: software for studying emotional signaling in economic bargaining games.

EMOTLAB software creates a virtual social environment in which individuals interact via computer with a virtual interaction partner in a series of economic bargaining games. The virtual partner appears on the participant's computer screen as a digital image (e.g., video or picture file) during each trial. A key feature of EMOTLAB software is its ability to control both the strategic behavior and the emotion signaling behavior (e.g., anger vs. embarrassment) of the virtual interaction partner. By simply editing a series of text files that control the subroutines governing the different features of the experiment (payoff structure, number of trials, etc.), EMOTLAB can generate an essentially infinite number of different social bargaining situations in which participants earn monetary payoffs contingent upon their decisions. This paper provides an overview of this software and how one can edit various subroutines to generate a typical experimental session in which research participants encounter a virtual interaction partner who displays different emotional signals.

Recent advances in operant conditioning technology: a versatile and affordable computerized touchscreen system.

We report the construction of a new operant chamber that incorporates modern computer, touchscreen, and display technologies. An LCD display was housed in the front wall of a lightweight Plexiglas chamber. An Apple eMac computer was used to present visual stimuli on the monitor and to control other chamber events. Responses to the stimuli were recorded using a transparent resistive-type touchscreen that overlaid the monitor. The resulting system is simple and inexpensive to construct but powerful and flexible enough to explore a broad range of issues in animal learning and behavior.

An infant-based assessment of early lexicon acquisition.

The majority of research on the acquisition of spoken language has focused on language production, due to difficulties in the assessment of comprehension. A primary limitation to comprehension assessment is maintaining the interest and attention of younger infants. We have developed an assessment procedure that addresses the need for an extensive performance-based measure of comprehension in the 2nd year of life. In the interest of developing an engaging approach that takes into account infants' limited attention capabilities, we designed an assessment based on touchscreen technology. This approach builds upon prior research by combining standardization and complexity with an engaging infant-friendly interface. Data suggest that the touchscreen procedure is effective in eliciting and maintaining infant attention and will yield more extensive and reliable estimates of early comprehension than do other procedures. The software to implement the assessment is available free of charge for academic purposes.

Actigraphic assessment of sleep-wake rhythm during the first 6 months of life.

OBJECTIVES: To examine the validity of the "Gaehwiler" actigraph (Gaehwiler Electronics, model Z80-32k V(1)) for the assessment of sleep-wake (S/W) rhythm and sleep structure in infants during the first 6 months of life using an algorithm developed in our laboratory to differentiate sleep and wake states. METHODS: A continuous 72 h actigraphic recording was performed in 10 healthy infants at 1, 3 and 6 months of age. The actigraphic data were matched to direct observation of the infants' behavioural states. Using discriminant function analysis a scoring algorithm for automatic identification of S/W states from raw activity data was developed. The chi-square periodogram analysis was performed to estimate periodic components of S/W rhythm. RESULTS: The overall agreement rates between the actigraphic and observer scoring for S/W were between 87 and 95% for the infants after the third month of life, while for the 1-month-old infants they never exceeded 72%. The actigraphic discrimination between active and quiet sleep was the best in 3-month-old infants. The circadian influence on S/W rhythm was already present by the end of the first month of life. CONCLUSIONS: Using the "Gaehwiler" actigraph in our study, valid discrimination between sleep and wake states was obtained in infants during 3 and 6 months. The actigraph, however, did not provide valid active vs. quiet sleep state measures. The circadian rhythm of S/W was observed as early as during the first month of life.

The cryoloop: an adaptable reversible cooling deactivation method for behavioral or electrophysiological assessment of neural function.

We describe a very adaptable reversible inactivation technique for the behavioral or electrophysiological analysis of neural circuits. The cryoloop device can be permanently implanted or topically applied in an acute preparation to apply cold to discrete surface regions of the central nervous system (e.g. cerebral cortex or midbrain). The cryoloop consists of a custom shaped, stainless steel, hypodermic tubing and cooling is effected by passing chilled methanol through the lumen of the tubing. Cryoloop temperature is monitored by a microthermocouple attached to the union of the loop, and can be maintained within +/- 1 degrees C of a desired temperature. In chronic preparations, implanted cryoloops have been maintained in cats and monkeys for periods in excess of 2 years. After this period there are no structural, metabolic of functional changes in the deactivated tissue, and full reversibility of cooling-induced effects is maintained. Operation of multiple cryoprobes provides great flexibility of experimental protocols, permits double and triple functional dissociations to be made, and strengthens experimental design considerably.

An automated method for the assessment of spontaneous and stereotyped climbing behavior in mice. Effects of the selective D1- and D2-dopamine receptor agonists SKF-38393 and RU-24926 and their association.

A video-tracking technique has been used for the evaluation of climbing behavior in mice. An automated image analysis system, the Videotrack 512 (Electronique Lyonnaise), was adapted for this specific application. This allowed distinguishing between spontaneous climbing and stereotyped climbing. The activity duration of mice was simultaneously measured. In order to validate this method, in the present study the ability of apomorphine to induce climbing in mice, and the effects of the D1-dopamine receptor agonist SKF-38393 and the D2-dopamine agonist RU-24926 and their association were investigated.

[The assessment of the action of pharmacological agents based on a new computer program for analysing animal operant behavior]. / Otsenka deistviia farmakologicheskikh sredstv na osnove novoi komp'iuternoi programmy dlia analiza operantnogo povedeniia zhivotnykh.

The new programme is developed for the experimental automatization and analysis of animal operant behavior in Skinner's box (Lafayette Instrument Co., USA) by means of the Apple 2e computer (USA). The fundamental of the programme is the division of the training procedure into different functional intervals. Operant behavior of rats is determined by diverse schedules of food and water reinforcement and electric shock. Rats were trained to response on schedules FR 20, FI 1, drug discrimination. Phenazepam (2 mg/kg) markedly decreases the number of responses on schedule FR 20. Phenazepam is a discriminable stimulus. The experimental results make it possible to use the programme for modelling various forms of operant behavior and analysing pharmacological properties of the well-known and new drugs.

Neuropharmacological and physiological validation of a computer-controlled two-compartment black and white box for the assessment of anxiety.

1. The two-compartment black and white box first described by Crawley and Goodwin (1980) has been used to study anti-anxiety properties of drugs but has not been validated. 2. An automated test system and validation of the protocol for the evaluation of compounds with anxiolytic or anxiogenic potential is described. 3. The box is partitioned into black and white sections with an interconnecting opening and is equipped with micro-switch photoelectric controls (light source and photoreceiver) and an interface connected to the menu-driven computer during anxiety testing. 4. Plasma corticosterone levels in naive mice maintained on a reversed L:D cycle was significantly reduced following restricted exposure to the brightly lit white section but not in the red-illuminated black section. 5. The optimal structural configuration in different test situations was found to be a square rather than a round box. 6. Under normal conditions, mice spend about 60% of the time in the dark compartment so that the exploratory activities and time spent in the white section are taken as a measure of anxiety. 7. Compounds examined included the reference anxiolytic diazepam, nicotine, naloxone, MDL 72222, ICS 205 930 and buspirone, all of which increased mouse exploratory activities in the white section. PTZ, beta-CCP, morphine and amphetamine increased exploration in the black compartment and reduced exploration in the white area. 8. Fluphenazine and imipramine had no specific effects on anxiety responding, although the cataleptogenic effect of fluphenazine was apparent. 9. Daily repeated testing was possible with a maximum of up to four trials a week using naive animals during the 5-min test session. 10. The results suggest that the rapid and automated test system for the assessment of changes in measures of anxiety is not only valid for large scale evaluation of compounds but could be used to elucidate mechanisms of drug action and the CNS pathways linked with anxiolysis and/or anxiogenesis.

A simple, inexpensive rotometer for automatically recording the dynamics of circling behavior.

An inexpensive, automated system for recording circling behavior in small animals is described. The apparatus provides information concerning: left and right full (360 degrees) rotations, half (180 degrees) turns, the time it takes for a rotation, the number of consecutive rotations in each direction, reversals (180 degree changes in direction), net rotations which are displayed directly without a source of electrical power, plus other parameters of circling behavior. The system is simple in principle and construction, and is virtually maintenance free. Depending on the options desired, a single rotometer can be built for approximately $350 or less than $70 by anyone able to use basic hand tools.

An assessment of spectral analysis of amphetamine-induced behavior.

Testing of a new radio frequency capacitance field type transducer and power spectrum analysis system for assessment of rat behavior is described. Power spectrum estimates of amphetamine-induced behavior had an orderly relationship with behavior ratings ranging from inactive to intense stereotypy. The effects of thorazine dose-response blocking on amphetamine-induced behavior were linear. Separation between adjacent doses could not be accomplished with a single frequency, but required differential frequency-time period information.