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The aim of the present review is to discuss how housing conditions affect behavioral performance in laboratory rodents from an ethological view. Commonly used laboratory rodents such as rats and mice, are originally captured animals that largely retain species-typical natural behaviors, while have fully adapted to a laboratory setting after long-term domestication. Laboratory settings including caging and artificial group housing are a considerable ethological factor influencing rodents' behaviors in commonly employed behavioral test paradigms, including emotional and defensive behaviors, learning and memory, and attention-related behaviors. Particularly, isolation rearing, single-housed in a cage, is referred to a deprivation of social relationships with cagemates, has a substantial impact on behavioral performance in laboratory rodents. In this review, we will fully examine the importance of caging related ethological factors, e.g., social relationships and its deprivation, which are essential for unraveling the nature of housing effect in laboratory rodents. These discussions regarding the housing conditions will provide valuable information for appropriately conducting behavioral studies and interpreting data of rodents' behaviors in neuroscience., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Huntington's disease (HD) is an autosomal dominant, neurodegenerative disorder with a characteristic triad of cognitive, affective and motor symptoms. Transgenic HD mice show excellent construct and face validity for many of these symptoms, however the decline in some facets of every day activity in humans is difficult to model. One approach is the assessment of species-relevant behaviors. Here we described three ethologically appropriate tests in the mouse-olfactory sensitivity, nest-building and sexually-motivated vocalizations. In R6/1 HD mice, olfactory and nest-building tests were sensitive to early dysfunctions induced by the HD mutation. Male vocalization testing revealed a late-stage sexual disinterest in R6/1 HD mice compared to WT littermates. We show that essential, species-relevant functions are disrupted by the HD mutation. The development of integrative behavioral assays which more closely model 'activities of daily living' (ADL) will facilitate the testing of novel therapeutic interventions in animal models as well as their clinical translation., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Acoustic communication between animals requires them to detect, discriminate, and categorize conspecific or heterospecific vocalizations in their natural environment. Laboratory studies of the auditory-processing abilities that facilitate these tasks have typically employed a broad range of acoustic stimuli, ranging from natural sounds like vocalizations to "artificial" sounds like pure tones and noise bursts. However, even when using vocalizations, laboratory studies often test abilities like categorization in relatively artificial contexts. Consequently, it is not clear whether neural and behavioral correlates of these tasks (1) reflect extensive operant training, which drives plastic changes in auditory pathways, or (2) the innate capacity of the animal and its auditory system. Here, we review a number of recent studies, which suggest that adopting more ethological paradigms utilizing natural communication contexts are scientifically important for elucidating how the auditory system normally processes and learns communication sounds. Additionally, since learning the meaning of communication sounds generally involves social interactions that engage neuromodulatory systems differently than laboratory-based conditioning paradigms, we argue that scientists need to pursue more ethological approaches to more fully inform our understanding of how the auditory system is engaged during acoustic communication. This article is part of a Special Issue entitled "Communication Sounds and the Brain: New Directions and Perspectives"., (Copyright © 2013 Elsevier B.V. All rights reserved.)

The Barnes maze is a visuo-spatial learning and memory test originally designed for use with rats, and later adapted for use with mice. The Barnes maze design and test procedure vary across studies using mice, but the effects of variation in Barnes maze design and test procedure on learning and memory in mice have not yet been investigated. Therefore the present experiment investigates whether test procedures, such as the number of habituation trials and parameters of the probe trial (correct zone size and trial length) influence learning and memory performance on three Barnes maze designs that differed in size and the presence of a wall with intra-maze visual cues. Performance was compared across the three mazes to determine how apparatus design influences visuo-spatial cue use. The number of habituation trials and parameters of the probe trial had small effects on learning and memory performance. Apparatus design, had little effect on acquisition performance but had a significant effect on memory performance. Mice on a maze with a small diameter, external wall and intra-maze visual cues had very poor visuo-spatial memory relative to mice tested on small and large diameter mazes without a wall or intra-maze visual cues. Assessment of visuo-spatial cue use indicated that mice do not rely on visuo-spatial cues to locate the escape hole on the small-diameter maze with a wall and intra-maze visual cues, but show reliable visuo-spatial cue use on small or large diameter mazes with no wall. These results indicate that apparatus design influences search strategy use and memory performance on the Barnes maze, and that including a wall around the edge of the Barnes maze decreases visuo-spatial cue use., (Copyright © 2011 Elsevier B.V. All rights reserved.)

The acoustic startle response (ASR) is a reflexive contraction of skeletal muscles in response to a loud, abrupt acoustic stimulus. ASR magnitude is reduced if the startle stimulus is preceded by a weaker acoustic or non-acoustic stimulus, a phenomenon known as prepulse inhibition (PPI). PPI has been used to test various aspects of sensory discrimination in both animals and humans. Here we show that PPI of the ASR is an advantageous method of assessing frequency discrimination. We describe the apparatus and its performance testing frequency discrimination in young CD1 mice. Compared to classical conditioning paradigms, PPI of the ASR is less time consuming, produces robust results, and can be used without training even in young animals. This approach can be used to investigate the neuronal mechanisms underlying frequency discrimination, its maturation during development, and its relationship to tonotopic organization., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Defining genetic networks underlying animal behavior in a high throughput manner is an important but challenging task that has not yet been achieved for any organism. Using Caenorhabditis elegans, we collected quantitative parametric data related to various aspects of locomotion from wild type and 31 mutant worm strains with single mutations in genes functioning in sensory reception, neurotransmission, G-protein signaling, neuromuscular control or other facets of motor regulation. We applied unsupervised and constrained K-means clustering algorithms to the data and found that the genes that clustered together due to the behavioral similarity of their mutants encoded proteins in the same signaling networks. This approach provides a framework to identify genes and genetic networks underlying worm neuromotor function in a high-throughput manner. A publicly accessible database harboring the visual and quantitative behavioral data collected in this study adds valuable information to the rapidly growing C. elegans databanks that can be employed in a similar context., (Copyright © 2011 Elsevier B.V. All rights reserved.)

The free-exploratory paradigm (FEP) is currently the only proposed animal model of trait anxiety, making it highly valuable to behavioural neuroscience. However, FEP has not yet been automated, so its results depend on human scoring, which can be quite imprecise. The aim of this study was, therefore, to validate an automated version of FEP, using a commercially available video-tracking system (ANY-maze(©) - Stoelting Co., USA). To achieve this, two experiments were performed. The first one evaluated the reliability of the video-based automation of FEP, and the second, assessed whether the zeolites, used as a bedding material in the first experiment to facilitate video-tracking, influenced the animals' behaviour in FEP. In experiment I, 15 drug-naive, adult, male rats were tested in FEP, while their behaviour was simultaneously evaluated by ANY-maze(©) and two human observers. Subsequently, the intraclass correlation coefficient (ICC) was calculated for the automated and manual results of the parameters "percentage of time in the novel side" (%TNS) and "total units visited" (TUV). The analysis resulted in high, significant values of ICC (%TNS: 0.9962 and TUV: 0.9453). In experiment II, 18 drug-naive, adult, male rats were allocated to two different groups: (1) tested in FEP with zeolites; and (2) tested in FEP with sawdust. The data obtained were analysed using the Student's t-test, which revealed no significant differences between the groups for the parameters %TNS and TUV. In conclusion, the data presented here show that automation of FEP, using a video-based tracking system, is not only possible, but also highly reliable., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Behavioral experiments based on operant procedures can be time-consuming for small amounts of data. While individual testing and handling of animals can influence attention, emotion, and behavior, and interfere with experimental outcome, many operant protocols require individual testing. We developed an RFID-technology- and transponder-based sorting system that allows removing the human factor for longer-term experiments. Identity detectors and automated gates route mice individually from their social home cage to an adjacent operant compartment with 24/7 operation. CD1-mice learnt quickly to individually pass through the sorting system. At no time did more than a single mouse enter the operant compartment. After 3 days of adjusting to the sorting system, groups of 4 mice completed about 50 experimental trials per day in the operant compartment without experimenter intervention. The automated sorting system eliminates handling, isolation, and disturbance of the animals, eliminates experimenter-induced variability, saves experimenter time, and is financially economical. It makes possible a new approach for high-throughput experimentation, and is a viable tool for increasing quality and efficiency of many behavioral and neurobiological investigations. It can connect a social home cage, through individual sorting automation, to diverse setups including classical operant chambers, mazes, or arenas with video-based behavior classification. Such highly automated systems will permit efficient high-throughput screening even for transgenic animals with only subtle neurological or psychiatric symptoms where elaborate or longer-term protocols are required for behavioral diagnosis., (Copyright © 2011 Elsevier B.V. All rights reserved.)

We present a paradigm for assessing visuospatial working memory and skill learning in a rodent model, based on the place avoidance test. In our allothetic place avoidance alternation task (APAAT) the paradigm is comprised of minimal training sessions, tests various aspects of learning and memory and provides a rich set of parameters. A single working memory session consists of four conditions: habituation (no shock), two place avoidance training intervals (shock activated) and a retrieval test (shock inactivated). The location of the shock sector is alternated for each training day which initially requires extinction of previous representations and further working memory to achieve effective place avoidance across sessions. Visuospatial skill memory was evaluated by the shock/entrance ratio by tracking locomotor activity which is essential to execute a place avoidance strategy. For each day rats learned to avoid a new place with shock, as shown by a decreased number of entrances, and an increased time to the first entrance and maximum avoidance time. Skill learning improved according to the decreased number of shocks per entrance across conditions. These results indicate that complex cognitive functions are captured by this behavioral method. This APAAT paradigm expands and complements existing tools for studying hippocampal-prefrontal dependent functions to support development of treatment interventions., (Copyright (c) 2010 Elsevier B.V. All rights reserved.)

This paper proposes a novel robot/insect mixed society setup which enhances the possibilities for insect behavioral research and can be used as a powerful tool for interdisciplinary studies on insect behavior. Micro-robots are equipped with decoys so as to allow a controlled dynamic interaction with crickets, Gryllus bimaculatus. A camera records the interaction and the video is later processed for the automatic tracking of each encounter between cricket and robot. A novelty of our method lies in using the robots as tools for the controlled evoking of specific insect behaviors rather than trying to build an insect-like robot. The possibility for performing controlled repeatable movements allows the stimulation of certain insect behaviors that are usually difficult to trigger using insects alone, allowing consistent behavioral research. A set of experiments were performed in order to validate the proposed setup. We also demonstrate the use of our setup for stimulating agonistic behavior during an electromyography recording session., ((c) 2010 Elsevier B.V. All rights reserved.)

The whisker to barrel system in rodents has become one of the major models for the study of sensory processing. Several tens of whiskers (or vibrissae) are distributed in a regular manner on both sides of the snout. Many tactile discrimination tasks using this system need multiple contacts with more than one whisker to be solved. With the aim of mimicking those multi-whisker stimuli during electrophysiological recordings, we developed a novel mechanical stimulator composed of 24 independent multi-directional piezoelectric benders adapted to the five rows and the five caudal arcs of the rat whisker pad. The most widely used technology for producing mechanical deflections of the whiskers is based on piezoelectric benders that display a non-linear behavior when driven with high frequency input commands and, if not compensated, show high unwanted ringing at particular resonance frequencies. If not corrected, this non-linear behavior precludes the application of high frequency deflections and the study of cortical responses to behaviorally relevant stimuli. To cope with the ringing problem, a mechanical and a software based solutions have been developed. With these corrections, the upper bound of the linear range of the bender is increased to 1 kHz. This new device allows the controlled delivery of large scale natural patterns of whisker deflections characterized by rapid high frequency vibrations of multiple whiskers., ((c) 2010 Elsevier B.V. All rights reserved.)

Intracranial self-stimulation (ICSS) is a sophisticated paradigm that can be used to assess the rewarding properties of drugs of abuse such as cocaine and amphetamine. Initial studies using this method to assess brain stimulation reward (BSR) examined the enhancement of response rates after drug administration. In the mid to late 1980s several groups began implementing paradigms to assess the direct rewarding effects of drugs of abuse that, for the most part, are independent of rate (i.e., progressive-ratio, auto-titration, rate-frequency curve), providing a representative assessment of a drugs rewarding effects. However, some drugs such as morphine and ethanol, which are known to have abuse potential, have sedative effects that may impede the ability to accurately quantify rewarding effects, even in these rate-independent paradigms. Few studies to date report effects of morphine in the ICSS paradigm and those that do appear to be inconsistent, lack robustness, have not been reproducible by other groups, or require inconvenient experimental designs. Here, we demonstrate a reliable and robust method to assess the rewarding effects of morphine using the rate-frequency curve paradigm., ((c) 2010 Elsevier B.V. All rights reserved.)

Drosophila olfactory aversive conditioning has served as a powerful model system with which to elucidate the molecular and neuronal mechanisms underlying memory formation. In the typical protocol, flies are exposed to a constant odor stream while receiving a pulsed electric shock in the conditioning tube of a manual apparatus. We have devised a simple, low-cost semi-automated conditioning apparatus that computationally controls the delivery of odor and shock. A semiconductor-based odor sensor is employed to monitor the change of odor concentration in the training tube. The system thus allows electric shocks to be precisely matched with odor concentration in the training tube. We found that short-term memory performance was improved with a pulsed odor flow protocol, in which odor is presented in short pulses, each paired with electric shock, rather than as a constant flow. The effect of pulsed odor flow might be ascribed to the phenomenon of 'conditioned approach', where approach toward an odor is induced when the electric shock is presented before odor pulse ends. Our data shows that the system is applicable to the study of olfactory memory formation and to the examination of conditioning parameters at a level of detail not practical with a manual apparatus., (Copyright (c) 2010 Elsevier B.V. All rights reserved.)

The CANTAB (Cambridge Neuropsychological Test Automated Battery), a system developed for human neuropsychological testing, has previously been used to assess cognitive function in two species of nonhuman primates, common marmoset monkeys and rhesus macaques. We describe the application of the system to the juvenile baboon, a nonhuman primate species offering specific investigative advantages. Juvenile baboons were trained and tested on a progressive ratio task to assess motivation, simple discrimination and simple reversal tasks to assess associative learning, and intra- and extra-dimensional set-shifting tasks to assess selective attention and attentional set-shifting, respectively. Study subjects were 8 juvenile baboons (Papio sp.), 4 females and 4 males aged 3.0+/-0.1 (mean+SEM) years and weight 8.2+/-0.4 kg. All baboons were easily trained, readily learned the neuropsychological tests and exhibited a stable performance. Applying a method such as the CANTAB has significant implications for expanding on the translational utility of the baboon in studies of neurodevelopment., (Copyright (c) 2010 Elsevier B.V. All rights reserved.)

The experimental study of nectar foraging behavior in free-flying bees requires the use of automated devices to control solution delivery and measure dependent variables associated with nectar gathering. We describe a new computer-controlled artificial flower and provide calibration data to measure the precision of the apparatus. Our device is similar to a "Skinner box" and we present data of an experiment where various amounts of a 50% sugar solution are presented randomly to individual bees. These data show large individual variations among subjects across several dependent variables. Finally, we discuss possible applications of our device to problems in behavioral sciences., (Copyright (c) 2010 Elsevier B.V. All rights reserved.)

Small teleost fish are increasingly used for studying the genetic basis of vision. In particular, zebrafish (Danio rerio) and medaka (Oryzias latipes) are commonly used vertebrate model organisms in developmental research, including research on the development of visual function. A multitude of behavior-based visual tests are established for larvae that have been successfully used to identify and characterize visual defects in genetically manipulated strains of these species. Testing the visual system of adult fish has proven to be more difficult for a number of reasons, including complications in restraining fish, or shoaling and dominance behavior interfering with visual behavior in population screening assays. In this paper, we present a simple and cost-effective method to quantitatively measure the optokinetic response (OKR) of individual adult zebrafish and medaka, which can be used to characterize visual capabilities of adult fish. This method can be applied to any fish species of similar size., ((c) 2009 Elsevier B.V. All rights reserved.)

The archer fish (Toxotes chatareus) exhibits unique visual behavior in that it is able to aim at and shoot down with a squirt of water insects resting on the foliage above water level and then feed on them. This extreme behavior requires excellent visual acuity, learning, and tight synchronization between the visual system and body motion. This behavior also raises many important questions, such as the fish's ability to compensate for air-water refraction and the neural mechanisms underlying target acquisition. While many such questions remain open, significant insights towards solving them can be obtained by tracking the eye and body movements of freely behaving fish. Unfortunately, existing tracking methods suffer from either a high level of invasiveness or low resolution. Here, we present a video-based eye tracking method for accurately and remotely measuring the eye and body movements of a freely moving behaving fish. Based on a stereo vision system and a unique triangulation method that corrects for air-glass-water refraction, we are able to measure a full three-dimensional pose of the fish eye and body with high temporal and spatial resolution. Our method, being generic, can be applied to studying the behavior of marine animals in general. We demonstrate how data collected by our method may be used to show that the hunting behavior of the archer fish is composed of surfacing concomitant with rotating the body around the direction of the fish's fixed gaze towards the target, until the snout reaches in the correct shooting position at water level.

The elevated plus-maze is a device widely used to assess rodent anxiety under the effect of several treatments, including pharmacological agents. The animal is placed at the center of the apparatus, which consists of two open arms and two arms enclosed by walls, and the number of entries and duration of stay in each arm are measured for a 5-min exposure period. The effect of an anxiolytic drug is to increase the percentage of time spent and number of entries into the open arms. In this work, we propose a new measure of anxiety levels in the rat submitted to the elevated plus-maze. We represented the spatial structure of the elevated plus-maze in terms of a directed graph and studied the statistics of the rat's transitions between the nodes of the graph. By counting the number of times each transition is made and ordering them in descending frequency we represented the rat's behavior in a rank-frequency plot. Our results suggest that the curves obtained under different pharmacological conditions can be well fitted by a power law with an exponent sensitive to both the drug type and the dose used.

A new method for designing vocalization based stimuli for experiments in auditory neurophysiology is described. This analysis-synthesis technique leverages a state space statistical signal model and the extended Kalman smoother for tracking the frequency, amplitude, and phase information of harmonically related components in recorded vocalizations. Using the same state space model, these parameters can then be used to synthesize the vocalizations and random or deterministic variants of the vocalizations. This method is shown to outperform short-time Fourier transform based frequency tracking methods in both noisy and noise-free synthetic test signals. It is further shown to accurately track recorded hummingbird, human, and bat vocalizations while removing recording artifacts such as noise, echo, and digital aliasing in the synthesis phase.

Songbirds are the preeminent animal model for understanding how the brain encodes and produces learned vocalizations. Here, we report a new statistical method, the Kullback-Leibler (K-L) distance, for analyzing vocal change over time. First, we use a computerized recording system to capture all song syllables produced by birds each day. Sound Analysis Pro software [Tchernichovski O, Nottebohm F, Ho CE, Pesaran B, Mitra PP. A procedure for an automated measurement of song similarity. Anim Behav 2000;59:1167-76] is then used to measure the duration of each syllable as well as four spectral features: pitch, entropy, frequency modulation, and pitch goodness. Next, two-dimensional scatter plots of each day of singing are created where syllable duration is on the x-axis and each of the spectral features is represented separately on the y-axis. Each point in the scatter plots represents one syllable and we regard these plots as random samples from a probability distribution. We then apply the standard information-theoretic quantity K-L distance to measure dissimilarity in phonology across days of singing. A variant of this procedure can also be used to analyze differences in syllable syntax.

We have developed an accurate and inexpensive system for recording the path taken by a moving insect. The system consists of a low-mass ball on which the loosely tethered insect runs, an optical sensor to detect rotation of the ball, and software written in Visual Basic 6.0 that interprets and records the hardware's output. The ball floats on a cushion of air. The optical sensor's output is encoded as changes in x, y coordinates. The software monitors this output continually, and records each new x, y pair and the time at which it occurred. Since the system records only those data that have changed, the output files are compact. In its present form, the system is calibrated to detect changes in the animal's position roughly equivalent to one body length. It can accurately record the details of paths hundreds of meters long. We have applied the system to measure the paths taken by female crickets in response to male calls that differ in their temporal structure.

A beam-walking apparatus has been evaluated for its ability to detect motor impairments in mice acutely treated with the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, 30 mg/kg, s.c., single or double administration). Mice subjected to MPTP lesioning showed deficits in motor performance on the beam-walking task, for up to 6 days post-MPTP administration, as compared to saline-treated controls. In addition, MPTP-treated mice were detected to have a marked depletion in striatal dopamine levels and a concomitant reduction in substantia nigra (SN) tyrosine hydroxylase (TH) immunoreactivity, at 7 days post-MPTP administration, indicative of dopaminergic neuronal loss. Pre-administration of the potent MAO-B inhibitor R-(-)-deprenyl at 3 or 10 mg/kg, 30 min, s.c, significantly inhibited the MPTP-induced reduction in SN TH-immunoreactivity, striatal dopamine depletions and impairments in mouse motor function. The data described in the present study provides further evidence that functional deficits following an acute MPTP dosing schedule in mice can be quantified and are related to nigro-striatal dopamine function.

Behaviour of senescence-accelerated (P/8) and resistant (R/1) mice was assessed using an ethological approach in a longitudinal study for exploratory and anxiety related behaviours (home cage activity, open field, elevated plus-maze and new object tests), cognitive abilities (step-down and step-through passive avoidance and water maze tests) and visual acuity (visible cliff test). Overall, P/8 mice showed higher activity induced by new environmental stimuli, higher anxiety and lower novelty seeking behaviour in the new object test than R/1 mice. P/8 mice showed an impaired performance as compared to R/1 mice in two passive avoidance tasks. Behavioural alterations of P/8 mice were already apparent at the age of 10-12 weeks. Factor analyses indicated that the impairment of P/8 mice in passive avoidance tasks relates to their altered exploratory and anxiety-related behaviour rather than to cognitive impairments. In the water maze, both strains performed badly in the visible platform task, suggesting poor visual abilities in both strains as supported by the visible cliff test. We conclude that, for a better interpretation of cognitive abilities of P/8 mice, tests not based on novelty-induced behaviour, visual acuity and good motor skills should be used. Finally, we question whether P/8 mice could be a model of some forms of neuropsychiatric disorders resulting from developmental abnormalities rather than aging.

This paper describes a relatively cheap MC6809-based microcomputer designed to run experiments in real-time, and to use the hardware and software facilities of a larger (HOST) computer. Each microcomputer is capable of controlling a wide range of psychological and behavioural experiments, and includes 32K RAM, 4K EPROM, 32 digital input lines, 32 digital output lines, analogue/digital converters, and programmable timers. Any programming language may be used, providing a cross-compiler generating MC6809 executable code exists for the HOST. Following over a year of use we can confirm that this system provides an effective method of running psychological and behavioural experiments.

A method is described to record the X,Y-coordinates of two bright spots on a TV image. These spots are produced by a light-emitting diodes (LEDs) assembly, which must be affixed on the moving target. The system was developed to record head movements of free-moving animals, chronically implanted to bear a socket LEDs holder, but it can be easily adapted to other applications, such as the measure of limb displacements in Man. Recordings are allowed up to 25 frames per second with an approximate spatial resolution of 255(X) X 300(Y). The method, which is based on standard TV equipment, involves a hardware interface, feeding the X and Y counts into a laboratory minicomputer and data acquisition software. A sample record is shown and other applications are discussed in relation to current non-video and video actographic techniques.

Computerized control of a bar-press feeding task initiated by a monkey's vocalization was designed to study the motivational roles of brain regions in feeding behavior. In this paradigm, the monkey was required to vocalize in order to initiate the task and then press the bar 30 times to obtain the reward. A microcomputer was used to sense the vocalization and to control the task. Using this system, changes in single neuron activity in the orbitofrontal cortex and the lateral hypothalamic area preceding the time of the vocalization were observed. The entire system including interface and control program is described.

Results are presented which illustrate the use of naturalistic observation techniques to study ongoing patterns of postural, gestural, and spacing behaviors among psychiatric patients hospitalized for acute psychiatric disorders. Behavioral frequencies are analyzed in terms of stable and labile characteristics by week of hospitalization, clinical diagnosis, and clinical outcome. Findings are interpreted from both clinical psychiatric and ethological perspectives. The discussion emphasizes the potential value of observational data gathering techniques for disorder assessment and theory development.