This work was supported by The National Institute of Health (NIH-2RO1NS033661) and by the Alabama Agricultural Experiment Station (HATCH ALA021-1-09017).

NOTE: All procedures performed here were submitted to and approved by IACUC (Office of Research Compliance) and were conducted following NIH guidelines. Mice used in the behavioral testing paradigm were naive and not used for other tests. The C57BL/6 Wild Type and Knock Out mice used in this protocol have been described previously9 and the data presented here are from that manuscript.
1. Preparation of the Testing Room and Open Field Apparatus
<ol>
	<li>Use a multiple unit open field maze (OFM) consisting of four activity chambers was used for this analysis (Figure 1). Each chamber measured 50 cm (length) x 50 cm (width) x 38 cm (height) and was made from white high density and non-porous plastic.</li>
	<li>Texture the floors of the maze for traction during ambulation while maze walls were smooth. Maze quadrants were completely empty for the purpose of this test. In consideration of the rest of this protocol, a single quadrant of the maze described above will be utilized to demonstrate the OFM.</li>
	<li>Wipe the chamber with a 95% Ethanol prior to use and before subsequent tests to remove any scent clues left by the previous subject mouse.</li>
	<li>Allow the ethanol to evaporate completely prior to testing mice. This may take 5-10 min between each testing session.</li>
	<li>For this analysis, use the SMART Video Tracking software from PanLab/Harvard Apparatus to record and evaluate mouse movement. 
	NOTE: Any commercial video tracking camera and software may be used to track the test subject and evaluate results from the open field maze. It is very important for the end user to understand how to calibrate and run the software used for each individual analysis. Regardless of the video camera and tracking software used, best results are obtained when the camera and software are correctly calibrated according to the manufacturer&#8217;s instructions.</li>
	<li>Perform the testing in a standard lit room capable of containing the maze apparatus and the computer required to run the software. Suspend the video camera above the maze either by attaching it to the ceiling or by using any elevated support system which allows the camera lens to see the entire maze area (Figure 2).</li>
	<li>As the human administrator of the test, be sure to have enough space in the room to be completely unobservable by the test subjects in the maze so as not to influence behavior of the mice.</li>
</ol>
2. Preparing the Software to Measure Activity
<ol>
	<li>Open the Video Tracking software.</li>
	<li>Once the software is opened, move the cursor to the &#8220;Single-subject tracking&#8221; option located under the &#8220;Data Acquisition&#8221; tab and single click to open this option.</li>
	<li>Choose the &#8220;Static Background&#8221; option located at the bottom of the screen.</li>
	<li>After choosing &#8220;Static Background&#8221; is chosen, it is necessary to use the software to take an image of the maze prior to addition of the test subjects. To do this, move the cursor to the &#8220;Photo&#8221; button located at the bottom of the screen and single click. 
	NOTE: The software will take a picture of the scenario without the test subject which will be subtracted from the image taken during the tracking process. This results in only the movement of the subject being analyzed by the software.</li>
	<li>Confirm that the background image taken above is completely removed by the tracking software by moving the cursor to the &#8220;Test&#8221; button located at the bottom of the screen and clicking once. A solid white field will be shown if the background image is completely removed from the tracking image. If lighting conditions change or the maze is accidentally moved, you will see black &#8220;shadows&#8221; in this field indicating the two images do not perfectly coincide. To remedy this situation, simply repeat step 2.4 above.</li>
	<li>After confirming background settings, use the Timing option to configure the way time is controlled during acquisition. To do this, move the cursor to the &#8220;Configuration&#8221; tab and click once on the &#8220;Timings&#8221; heading. Use the newly opened window to enter experimental parameters.</li>
	<li>For this protocol, chose the &#8220;Programmed time&#8221; option as 10 min tracking period. Set the &#8220;Latency period&#8221; to 5 sec to allow the user time to place the mouse in the center of the maze and move away prior to initiation of tracking. Enter the &#8220;Acquisition time&#8221; of 10 min for the duration of the test. Set the &#8220;Stop control&#8221; set to &#8220;When programmed time (10 min) is over&#8221; which will automatically turn off the camera and the tracking function of the software.</li>
	<li>Move the cursor to the &#8220;Close&#8221; button after all timings have been set to close the window. You are now ready to begin the testing procedure.</li>
</ol>
3. Administration of the Open Field Test
NOTE: The software package used in this protocol allows the tracking of up to 16 individual mice at one time. For ease of completion and as mentioned above, the protocol discussed here is for a single mouse using a single quadrant of the OFM. For the equipment in use for this protocol, a maximum of 4 individual mice could be tracked using each quadrant of the maze. If utilizing a multi-enclosure maze, after placing the first subject mouse in its defined quadrant, place the remaining mice into their respective maze quadrant for tracking analysis. For the purposes of this protocol, further instruction will be specific to a single quadrant of the maze.
<ol>
	<li>Bring the mice in their home cages from their housing room into the testing room. Allow the mice to acclimate to the procedure room for a minimum of 30 min prior to starting the test.</li>
	<li>Remove a single mouse from the home cage by gently grasping its tail and place the mouse in the middle of the open field maze while concurrently activating the SMART software by single clicking on the Start button to begin tracking mouse movement. It is normal for the mouse to move immediately to the periphery walls of the maze and the timing of release and tracking capture of the mouse should coincide to record this movement.</li>
	<li>Allow free and uninterrupted movement of the subject mouse throughout the respective quadrant of the maze for a single 10 min period during which time, the tracking software will record movement (Figure 3).</li>
	<li>At the end of the test period, pick up the subject mouse gently, removing it from the maze and return it to its home cage.</li>
	<li>Prior to cleaning the maze, visually count the fecal boli pellets present in the maze and manually record the numbers for further analysis.</li>
	<li>Remove all fecal pellets and wipe up all spots of urination. Spray the floor and walls of the maze quadrant with 95% ethanol and wipe down with a clean paper towel. Allow the ethanol solution to completely dry prior to testing other mice.</li>
	<li>Repeat the procedure with the next mouse.</li>
</ol>
4. Measurement and Analysis of Behavior During Testing Procedure
NOTE: For measurement, three aspects of open field behavior are readily characterized using this protocol (see discussion). A brief instruction on how to access these measurements in the video tracking software follows.
<ol>
	<li>From the main screen of the SMART software, move the cursor to the &#8220;Zones&#8221; tab and single click &#8220;Definition&#8221; to open the Zone Editor.</li>
	<li>Follow the detailed instructions in the SMART software User&#8217;s Manual do define zones or grids to overlay on the tracking paths. Here, the software was used to define a 5 x 5 grid of 10 cm squares covering the floor of the maze (Figure 4). Be sure to save the zone file created prior to closing the Zone Editor.</li>
	<li>From the main screen of the SMART software, move the cursor to the &#8220;Analysis&#8221; tab and single click to open the Data Analysis window.</li>
	<li>Move the cursor to the &#8220;File&#8221; tab and open the Zone file created above.</li>
	<li>Move the cursor to the &#8220;Configuration&#8221; tab and open the &#8220;Track Analysis&#8221; option. This will open the &#8220;Single-subject analysis configuration&#8221; window.
	<ol>
		<li>Move the cursor to the &#8220;Standard&#8221; tab and move the &#8220;Travelled distance&#8221; parameter from the Available Parameters box (left side) to the Included Parameters box (right side).</li>
		<li>Move the cursor to the &#8220;Zones Transitions&#8221; tab and move all appropriate parameters to the Included Parameters box as above.</li>
		<li>Make sure the &#8220;Full Track&#8221; box is checked at the bottom of the window.</li>
		<li>Move the cursor to the OK button and close the Single-subject analysis configuration window. 
		NOTE: Depending on the analysis you wish to perform, many other options can be chosen in this window to mine data from the analysis. Read the detailed User&#8217;s Manual of your specific program to determine what parameters are most important for analysis of your data.</li>
	</ol>
	</li>
	<li>Under the File tab at the upper left of the program window, open the Single subject track window and place a check mark beside all tracks being analyzed. Move the cursor to the Check Mark button at the top of the window and click to close the Track Explorer window.</li>
	<li>Move the cursor to the &#8220;Go&#8221; button in the Data Analysis window and single click to initiate analysis of the track data.</li>
	<li>Analysis data can be output as either ASCII text files or it can be directly exported into an EXCEL spreadsheet. Use the output tools of the software program you are using to output the data for your own use. 
	NOTE: Total distance traveled and time spent in indicated zones will be output following the data analysis steps outlined above. Again, it is stressed that the steps to reach these measurements represented here will differ depending on the user software used. But the data itself and the interpretation of the results should be similar independent of the software program used. It is also worth noting that test administrator bias is removed from this protocol as all the data collected is quantified data measured by the software and not the administrator. Thus there is no qualifiable element to the data collected as described.</li>
</ol>

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The authors have nothing to disclose.

The Open Field Maze is one of the most widely used platforms in animal behavioral studies. A number of important conventional and ethological parameters2,4 can be collected and analyzed during the performance of the OFM. These data allow the researcher to measure behaviors ranging from overall locomotor activity to anxiety-related emotional behaviors8. However, use of OFM is not without its shortcomings. One confounding issue is the wide range of static variables that can be manipulated during any t...

The Open Field Maze (OFM) was initially developed in 1934 as a test to measure emotionality in rodents1. It has attained the status of being one of the most widely used measures of behavior in animal psychology2. It provides an easy and fairly rapid assessment of well-defined behaviors requiring no training to the test subject and little to no specialized training for the human administering the test. These attributes have led to wide-spread use of the open field maze in research extended to other animal species such as calves, pigs, rabbits, primates, honeybees and lobsters3. Part of its popularity arises from the fact that the psychological and physiological concepts underlying the tests are generally straight-forward and well understood. For example, it has been postulated that evolutionary forces have selected for a common response in animals such that most species display anxiety-mediated fear or flight responses to specific stimuli. Rodents for example, show distinct aversions to large, brightly lit, open and unknown environments4. We can assume they have been phylogenetically conditioned to see these types of environments as dangerous. All of these features are incorporated in the open field maze and form the basis of its use in behavioral paradigm testing.
An open field maze consists of a wall-enclosed area that is of sufficient height to prevent the subject from escaping. Typical maze shapes are circular or square with an area large enough, based on the size of the subject tested, to elicit a feeling of openness in the center of the maze. A number of variables can be scored in the open field maze with most parameters involving differing types of motor activity2. Ambulation is the most common behavior studied but others such as latency or rearing can also be measured. Most often, rodent behavior is analyzed in a bare maze. However, the addition of objects, either one or many to the maze floor, adds the ability to see how the subject interacts with novel additional stimuli2. Relevant parameters when objects are presented are typically the number of approaches to an object or in some cases, preference or aversion for one object over another.
Many behavioral tests of anxiety are based on the subject animal&#8217;s body activity and locomotion5. Interpreting behavioral tests for emotionality while separating non-emotional confounding factors, such as motor activity, has been the subject of intense debate6,7. As the OFM was originally described, two measures of emotionality can be deduced, locomotor activity and fecal boli deposits or defecation1. However, these two measures have been shown in some studies to be unrelated supporting the conclusion that emotionality in rodents is multidimensional5. Regardless, discrepancies in the literature regarding these measures and emotionality or anxiety in mouse models may be attributed to differences in analysis criteria or differences in testing procedures. Studies have conclusively linked results from OFM analysis with other measures of anxiety when comparing mouse models8.

<table border="0" cellpadding="0" cellspacing="0" width="631">
	<tbody>
		<tr height="40">
			<td height="40" style="height:40px;width:160px;">Multi Unit Open Field Test</td>
			<td style="width:171px;">San Diego Instruments, Inc.</td>
			<td style="width:109px;">White 7001-0354</td>
			<td style="width:192px;">Any single or multi unit open field maze can be used</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:160px;">SMART DT Tracking Software</td>
			<td style="width:171px;">PanLab/Harvard Apparatus</td>
			<td style="width:109px;">76-0695</td>
			<td style="width:192px;">Any tracking software can be utilized with this protocol</td>
		</tr>
		<tr height="60">
			<td height="60" style="height:60px;width:160px;">Sony 990x Video Camera Recorder</td>
			<td style="width:171px;">Sony</td>
			<td style="width:109px;">CCD-TRV328</td>
			<td style="width:192px;">Any suitable video camera can be attached to computer for recording tracking profiles.</td>
		</tr>
	</tbody>
</table>

use of the open field maze to measure locomotor and anxiety-like behavior in mice

Animal models have proven to be invaluable to researchers trying to answer questions regarding the mechanisms of behavior. The Open Field Maze is one of the most commonly used platforms to measure behaviors in animal models. It is a fast and relatively easy test that provides a variety of behavioral information ranging from general ambulatory ability to data regarding the emotionality of the subject animal. As it relates to rodent models, the procedure allows the study of different strains of mice or rats both laboratory bred and wild-captured. The technique also readily lends itself to the investigation of different pharmacological compounds for anxiolytic or anxiogenic effects. Here, a protocol for use of the open field maze to describe mouse behaviors is detailed and a simple analysis of general locomotor ability and anxiety-related emotional behaviors between two strains of C57BL/6 mice is performed. Briefly, using the described protocol we show Wild Type mice exhibited significantly less anxiety related behaviors than did age-matched Knock Out mice while both strains exhibited similar ambulatory ability.

The average number of individuals per strain of mice tested in most cases is approximately 20 to generate sufficient statistical relevance. However, this number can be in the range of 8-30 depending on mouse availability. Depending on the measurement or comparisons required, it is also favorable to use age-matched subjects.
The first and arguably most important specific parameter to measure in the Open Field Maze is total ambulatory distance. While the unit of measure is irrelevant for compari...

Watch this Scientific Journal Video about Use of the Open Field Maze to Measure Locomotor and Anxiety-like Behavior in Mice at JoVE.com

Use of the Open Field Maze to Measure Locomotor and Anxiety-like Behavior in Mice

A protocol is provided to use an Open Field Maze to access general locomotor activity, anxiety and emotionality in a laboratory mouse model.

Animal models have proven to be invaluable to researchers trying to answer questions regarding the mechanisms of behavior. The Open Field Maze is one of ...

use-open-field-maze-to-measure-locomotor-anxiety-like-behavior

Universidad de Cartagena UDEC

Research

JoVE Journal

Behavior

72.2K Views.  Auburn University. A protocol is provided to use an Open Field Maze to access general locomotor activity, anxiety and emotionality in a laboratory mouse model.

Video: Use of the Open Field Maze to Measure Locomotor and Anxiety-like Behavior in Mice

Shallow Water (Paddling) Variants of Water Maze Tests in Mice

When Richard Morris devised his water maze in 19817, most behavioral work was done in rats. However, the greater understanding of mouse genetics led to the mouse becoming increasingly important. But researchers found that some strains of mutant mice were prone to problems like passively floating or diving when they were tested in the Morris water maze11. This was unsurprising considering their natural habitat; rats swim naturally (classically, the "sewer rat"), whereas mice evolved in the dry areas of central Asia.
To overcome these problems, it was considered whether shallow water would be a sufficient stimulus to provide escape motivation for mice. This would also avoid the problems of drying the small creatures with a towel and then putting them in a heated recovery chamber to avoid hypothermia, which is a much more serious problem than with rats; the large ratio of surface area to volume of a mouse makes it particularly vulnerable to rapid heat loss.
Another consideration was whether a more natural escape strategy could be used, to facilitate learning. Since animals that fall into water and swim away from the safety of the shore are unlikely to pass on their genes, animals have evolved a natural tendency to swim to the edge of a body of water. The Morris water maze, however, requires them to swim to a hidden platform towards the center of the maze - exactly opposite to their evolved behavior. Therefore the paddling maze should incorporate escape to the edge of the apparatus. This feature, coupled with the use of relatively non-aversive shallow water, embodies the "Refinement" aspect of the "3 Rs" of Russell and Burch8.
Various types of maze design were tried; the common feature was that the water was always shallow (2 cm deep) and escape was via a tube piercing the transparent wall of the apparatus. Other tubes ("false exits") were also placed around the walls but these were blocked off. From the inside of the maze all false exits and the single true exit looked the same. Currently a dodecagonal (12-sided) maze is in use in Oxford, with 12 true/false exits set in the corners. In a recent development a transparent paddling Y-maze has been tested successfully.

Shallow Water Paddling Variants of Water Maze Tests in Mice

Mice can swim, but many strains appear to find this activity stressful. To overcome this problem mazes have been devised where escape from shallow water is used to motivate behaviour. These have been demonstrated to support learning at least as good as the traditional and widely used Morris water maze.

When Richard Morris devised his water maze in 19817, most behavioral work was done in rats. However, the greater understanding of mouse genetics led to ...

Use of the Operant Orofacial Pain Assessment Device (OPAD) to Measure Changes in Nociceptive Behavior

We present an operant system for the detection of pain in awake, conscious rodents. The Orofacial Pain Assessment Device (OPAD) assesses pain behaviors in a more clinically relevant way by not relying on reflex-based measures of nociception. Food fasted, hairless (or shaved) rodents are placed into a Plexiglas chamber which has two Peltier-based thermodes that can be programmed to any temperature between 7 &deg;C and 60 &deg;C. The rodent is trained to make contact with these in order to access a reward bottle. During a session, a number of behavioral pain outcomes are automatically recorded and saved. These measures include the number of reward bottle activations (licks) and facial contact stimuli (face contacts), but custom measures like the lick/face ratio (total number of licks per session/total number of contacts) can also be created. The stimulus temperature can be set to a single temperature or multiple temperatures within a session. The OPAD is a high-throughput, easy to use operant assay which will lead to better translation of pain research in the future as it includes cortical input instead of relying on spinal reflex-based nociceptive assays.

Use of the Operant Orofacial Pain Assessment Device OPAD to Measure Changes in Nociceptive Behavior

We present a user-friendly, high-throughput operant system for the evaluation of pain behaviors in awake, conscious rodents. The Orofacial Pain Assessment Device (OPAD) can assess pain through a reward/conflict paradigm thus providing a more humane way of testing. This protocol will yield more clinically relevant and translational data from rodents.

We present an operant  system for the detection of pain in awake, conscious rodents. The Orofacial  Pain Assessment Device (OPAD) assesses pain behaviors ...

Use of an Eight-arm Radial Water Maze to Assess Working and Reference Memory Following Neonatal Brain Injury

Working and reference memory are commonly assessed using the land based radial arm maze.&#160;However, this paradigm requires pretraining, food deprivation, and may introduce scent cue confounds. The eight-arm radial water maze is designed to evaluate reference and working memory performance simultaneously by requiring subjects to use extra-maze cues to locate escape platforms and remedies the limitations observed in land based radial arm maze designs. Specifically, subjects are required to avoid the arms previously used for escape during each testing day (working memory) as well as avoid the fixed arms, which never contain escape platforms (reference memory). Re-entries into arms that have already been used for escape during a testing session (and thus the escape platform has been removed) and re-entries into reference memory arms are indicative of working memory deficits. Alternatively, first entries into reference memory arms are indicative of reference memory deficits. We used this maze to compare performance of rats with neonatal brain injury and sham controls following induction of hypoxia-ischemia and show significant deficits in both working and reference memory after eleven days of testing. This protocol could be easily modified to examine many other models of learning impairment.

The eight-arm radial water maze is designed to evaluate reference and working memory performance simultaneously by requiring subjects to use extra-maze cues to locate escape platforms and remedies the limitations observed in land based radial arm maze designs.

Working and reference memory are commonly assessed using the land based radial arm maze.&#160;However, this paradigm requires pretraining, food ...

Behavioral and Locomotor Measurements Using an Open Field Activity Monitoring System for Skeletal Muscle Diseases

The open field activity monitoring system comprehensively assesses locomotor and behavioral activity levels of mice. It is a useful tool for assessing locomotive impairment in animal models of neuromuscular disease and efficacy of therapeutic drugs that may improve locomotion and/or muscle function. The open field activity measurement provides a different measure than muscle strength, which is commonly assessed by grip strength measurements. It can also show how drugs may affect other body systems as well when used with additional outcome measures. In addition, measures such as total distance traveled mirror the 6 min walk test, a clinical trial outcome measure. However, open field activity monitoring is also associated with significant challenges: Open field activity measurements vary according to animal strain, age, sex, and circadian rhythm. In addition, room temperature, humidity, lighting, noise, and even odor can affect assessment outcomes. Overall, this manuscript provides a well-tested and standardized open field activity SOP for preclinical trials in animal models of neuromuscular diseases. We provide a discussion of important considerations, typical results, data analysis, and detail the strengths and weaknesses of open field testing. In addition, we provide recommendations for optimal study design when using open field activity in a preclinical trial.

Open field activity levels are used to assess locomotive and behavioral activity levels. This protocol provides a well-designed, standardized protocol to use in preclinical trials for neuromuscular disorders.

The open field activity monitoring system comprehensively assesses locomotor and behavioral activity levels of mice. It is a useful tool for assessing ...

The Attentional Set Shifting Task: A Measure of Cognitive Flexibility in Mice

Cognitive impairment, particularly involving dysfunction of circuitry within the prefrontal cortex (PFC), represents a core feature of many neuropsychiatric and neurodevelopmental disorders, including depression, post-traumatic stress disorder, schizophrenia and autism spectrum disorder. Deficits in cognitive function also represent the most difficult symptom domain&#160;to successfully treat, as serotonin reuptake inhibitors and tricyclic antidepressants have only modest effects. Functional neuroimaging studies and postmortem analysis of human brain tissue implicate the PFC as being a primary region of dysregulation in patients with these disorders. However, preclinical behavioral assays used to assess these deficits in mouse models which can be readily manipulated genetically and could provide the basis for studies of new treatment avenues have been underutilized. Here we describe the adaptation of a behavioral assay, the attentional set shifting task (AST), to be performed in mice to assess prefrontal cortex mediated cognitive deficits. The neural circuits underlying behavior during the AST are highly conserved across humans, nonhuman primates and rodents, providing excellent face, construct and predictive validity.

The goal of this protocol is to perform a behavioral assay such as the attentional set shifting task (AST) to assess prefrontal cortex-mediated cognitive flexibility in mice.

Cognitive impairment, particularly involving dysfunction of circuitry within the prefrontal cortex (PFC), represents a core feature of many ...

Place and Response Learning in the Open-field Tower Maze

This protocol describes how the Open-field Tower Maze (OFTM) paradigm is used to study spatial learning in rodents. This maze is especially useful for examining how rats learn to use a place- or response-learning to successfully navigate in an open-field arena. Additionally, this protocol describes how the OFTM differs from other behavioral maze paradigms that are commonly used to study spatial learning in rodents. The OFTM described in this article was adapted from the one previously described by Cole, Clipperton, and Walt (2007). Specifically, the OFTM was created to test spatial learning in rodents without the experimenter having to consider how &#8220;stress&#8221; might play a role as a confounding variable. Experiments have shown that stress-alone can significantly affect cognitive function1. The representative results section contains data from an experiment that used the OFTM to examine the effects of estradiol treatment on place- and response-learning in adult female Sprague Dawley rats2. Future studies will be designed to examine the role of the hippocampus and striatum in place- and response-learning in the OFTM.

The Open-field Tower Maze (OFTM) is a maze created to study the behavioral and neural mechanisms of spatial learning (e.g., place- or response-learning) in rats. This maze is especially useful for experimenters who want to use a non-stressful maze paradigm to investigate spatial learning in their research.

This protocol describes how the Open-field Tower Maze (OFTM) paradigm is used to study spatial learning in rodents. This maze is especially useful for ...

Basic Methods for the Study of Reproductive Ecology of Fish in Aquaria

Captive-rearing observations are valuable for revealing aspects of fish behavior and ecology when continuous field investigations are impossible. Here, a series of basic techniques are described to enable observations of the reproductive behavior of a wild-caught gobiid fish, as a model, kept in an aquarium. The method focuses on three steps: collection, transport, and observations of reproductive ecology of a substrate spawner. Essential aspects of live fish collection and transport are (1) preventing injury to the fish, and (2) careful acclimation to the aquarium. Preventing harm through injuries such as scratches or a sudden change of water pressure is imperative when collecting live fish, as any physical damage is likely to negatively affect the survival and later behavior of the fish. Careful acclimation to aquaria decreases the incidence death and mitigates the shock of transport. Observations during captive rearing include (1) the identification of individual fish and (2) monitoring spawned eggs without negative effects to the fish or eggs, thereby enabling detailed investigation of the study species' reproductive ecology. The subcutaneous injection of a visible implant elastomer (VIE) tag is a precise method for the subsequent identification of individual fish, and it can be used with a wide size range of fish, with minimal influence on their survival and behavior. If the study species is a substrate spawner that deposits adhesive eggs, an artificial nest site constructed from polyvinyl chloride (PVC) pipe with the addition of a removable waterproof sheet will facilitate counting and monitoring the eggs, lessening the investigator's influence on the nest-holding and egg-guarding behavior of the fish. Although this basic method entails techniques that are seldom mentioned in detail in research articles, they are fundamental for undertaking experiments that require the captive rearing of a wild fish.

A series of basic methods to enable the study of the reproductive ecology of fish kept in aquaria are described. These are useful protocols for collecting fish using SCUBA, transporting live fish, and observing the reproductive behavior of wild-caught fish kept in aquaria.

Captive-rearing observations are valuable for revealing aspects of fish behavior and ecology when continuous field investigations are impossible. Here, a ...

Central and Divided Visual Field Presentation of Emotional Images to Measure Hemispheric Differences in Motivated Attention

Two dominant theories on lateralized processing of emotional information exist in the literature. One theory posits that unpleasant emotions are processed by right frontal regions, while pleasant emotions are processed by left frontal regions. The other theory posits that the right hemisphere is more specialized for the processing of emotional information overall, particularly in posterior regions.
Assessing the different roles of the cerebral hemispheres in processing emotional information can be difficult without the use of neuroimaging methodologies, which are not accessible or affordable to all scientists. Divided visual field presentation of stimuli can allow for the investigation of lateralized processing of information without the use of neuroimaging technology. 
This study compared central versus divided visual field presentations of emotional images to assess differences in motivated attention between the two hemispheres. The late positive potential (LPP) was recorded using electroencephalography (EEG) and event-related potentials (ERPs) methodologies to assess motivated attention. Future work will pair this paradigm with a more active behavioral task to explore the behavioral impacts on the attentional differences found.

This study compared central versus divided visual field presentations of emotional images to assess differences in motivated attention between the two hemispheres. The late positive potential (LPP) was recorded using electroencephalography (EEG) and event-related potentials (ERPs) methodologies to assess motivated attention.

Two dominant theories on lateralized processing of emotional information exist in the literature. One theory posits that unpleasant emotions are processed ...

Testing Animal Anxiety in Rats: Effects of Open Arm Ledges and Closed Arm Wall Transparency in Elevated Plus Maze Test

The elevated plus maze test is a behavioral test for assessing animal anxiety in rodents. Although this test is widely applied in the field of behavioral science, conflicting outcomes are often provided from different laboratories. To identify reasons for the different outcomes, we previously focused on arm features, which differ between laboratories, most notably the presence/absence of ledges at the sides of open arms and the transparency/opaqueness of closed arm walls. In a previous report, we used a custom designed container to compare rat behavior on different combinations of open and closed arm designs under otherwise identical experimental conditions, and showed that differences in arm features interfere with experimental outcomes. In brief, open arm ledges significantly increased anxiety-like behavior in rats, while transparent arms may also have decreased this behavior. Furthermore, we verified a higher detection sensitivity of the effect of an anxiolytic drug in a combination of no-ledged open arm + opaque walled closed arm compared with a combination of ledged open arm + transparent walled closed arm. In this report, we introduce our protocol for the elevated plus maze test, together with discussion of the key results from the previous report and our experimental experience. We believe this report will provide useful information for researchers who have employed or who plan to use the elevated plus maze in their studies.

Rats' anxiety-like behavior tested by the elevated plus maze varies highly depending on the testing environment. Here we show how apparatus settings, especially arm structure, affect behavior on the maze, and we explain a reliable protocol to detect effects of anxiolytic drugs. This report will contribute to anxiety research.

The elevated plus maze test is a behavioral test for assessing animal anxiety in rodents. Although this test is widely applied in the field of behavioral ...

Analyzing Spatial Learning and Prosocial Behavior in Mice Using the Barnes Maze and Damsel-in-Distress Paradigms

The Barnes maze is a reliable measure of spatial learning and memory that does not require food restriction or exposure to extremely stressful stimuli. The Barnes maze can also assess other mouse behaviors, such as general motivation to escape from the maze platform and exploratory behavior. The Barnes maze can measure whether a genetic mutation or environmental variable can impact the acquisition and retention of spatial memories, as well as provide information about the search strategy employed by the mice. Here we use the Barnes maze to detect a memory deficit in adult mice following a single developmental ethanol exposure event. The newly described Damsel-in-Distress paradigm exposes a male mouse to a female mouse trapped in a chamber in the open center field of the arena. It provides an opportunity for the mouse to socially respond to the trapped female and exhibit prosocial behavior. The Damsel-in-Distress paradigm can also be used to examine mouse behavior in a novel arena and measure locomotor activity. Both the Barnes Maze and the Damsel-in-Distress protocols require minimal financial investment and most aspects of the tests can be constructed from common lab supplies. These flexible and accessible tools can also be used to detect behavioral changes over the course of development.

This protocol measures spatial learning and memory using the Barnes maze. A novel Damsel-in-Distress paradigm is used to assess locomotor activity and prosocial behavior in mice.

The Barnes maze is a reliable measure of spatial learning and memory that does not require food restriction or exposure to extremely stressful stimuli. ...