Zone Preference in the Visual Water Maze
June 26, 2025
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The modern lifestyle has made various health risks such as hypertension, heart disease, and other common cardiovascular conditions increasingly common. Picking the right sphygmomanometer is a smart choice that we should all consider daily, for the good of our healthy bodies.
The first blood pressure measurement was recorded in the year 1733, and the first sphygmomanometer was invented in the year 1881 by Samuel Siegfried Karl Ritter von Basch. The pioneering design consisted of two parts–a rubber bulb filled with water, and a mercury column. The water in the rubber bulb was used to restrict the blood flow in the artery, while the mercury column was connected to the bulb that translated the pressure required to obscure the pulse into millimeters of mercury completely. In 1896, Scipione Riva-Rocci made further improvements in Ritter’s first sphygmomanometer. He added a handcuff that could be fixed around the arm to apply pressure on the limb, to measure the blood pressure. This design became the standard for such devices later on.
In 1905, Dr. Nikolai Korotkoff discovered the difference between systolic blood pressure and diastolic blood pressure. This discovery laid the foundation for modern blood pressure measurement as we know it today. Simply put, when pressure is applied and released, they are accompanied by the appearance or disappearance of sounds within the arteries. These systolic and diastolic sounds are thus used as standards in blood pressure measurement and are known as Korotkoff sounds. The sphygmomanometer apparatus has since then evolved greatly to the available technology offered today, now more commonly known as the BP apparatus.
Advancements in the sphygmomanometer, or blood pressure gauges as they are also often called, have been quite impressive over the years. Medical devices have become more specialized, and various types of sphygmomanometers have become available in the market. Outlined in our list below are three major types of sphygmomanometers–mercury, aneroid, and digital.
Mercury Sphygmomanometer
The mercury sphygmomanometer is the most conventional form of blood pressure apparatus, and it can be considered the golden standard in the health industry. Mercury sphygmomanometers are made up of manually inflatable cuffs that are attached to measuring units with mercury-infused tubes. While operating the device, it is important to place the apparatus on a flat surface and in an upright position to get the correct readings. These devices are very delicate and require special care, and if accidentally dropped can cause a rupture of mercury, rendering the device useless and potentially hazardous.
The biggest advantage of using mercury sphygmomanometers is that they are quite easy to use, and if used properly, can last a lifetime. The device can produce the most accurate results without requiring much readjustment. Due to the toxic nature of its contents, however, the use of mercury sphygmomanometers has been banned in some countries, and other forms of sphygmomanometers are being used instead.
Aneroid Sphygmomanometer
Aneroid means “without fluid,” and as the name suggests, this type of BP apparatus doesn’t make use of any mercury and is therefore considered the safest alternative to mercury sphygmomanometers. Its recording procedures are pretty similar to that of the mercury sphygmomanometer, except the stethoscope’s attachment to the cuff. In the android device, the cuff is attached to a dial gauge with tubing. The gauge head contains mechanical parts that convert the cuff pressure into gauge-based reading. Additionally, there are various other types of aneroid sphygmomanometers depending on how they are used. These include pocket-aneroid sphygmomanometers, palm aneroid sphygmomanometers, and clock-style aneroid sphygmomanometers. Ultimately, the benefit of using aneroid sphygmomanometers is the affordability of the apparatus, as well as its compact and handy nature. However, similar to other devices used to measure blood pressure, aneroid sphygmomanometers make use of a delicate mechanism and therefore necessitates careful handling. Aneroid sphygmomanometers also require recalibration by experts, to avoid cases of faulty reading.
Automatic Digital Sphygmomanometer
The automatic digital sphygmomanometer is the most technologically-advanced sphygmomanometer design to date. These devices use an electronic pressure sensor to measure blood pressure, and the readings are presented on a digital display. Similar to mercury and aneroid sphygmomanometers, digital sphygmomanometers also come with inflatable cuffs, but there is a difference in the procedure for measuring blood pressure. Unlike the other two types, automatic digital sphygmomanometers evaluate and measure the fluctuations of arteries. These devices are perfect for home use as they are the easiest to operate. To avoid the risk of inaccurate readings, periodic counter checks with conventional mercury sphygmomanometers are recommended.
In making use of sphygmomanometers, procedures vary according to the type and variety of sphygmomanometer used, but all varieties operate on a single principle. A bulb increases the pressure by inflating the cuff placed around one’s arm, and a valve releases the pressure. During this process, a stethoscope is used to listen to arterial blood flow sounds. As the heartbeats, blood going through the arteries causes a rise in pressure, which quickly decreases when the heart’s ventricles prepare for another beat. This rise and fall are called systolic and diastolic pressure, respectively. Below are the steps to accurately measure one’s blood pressure.
Monitoring one’s blood pressure is a responsibility not just of doctors and physicians, but of every individual alike. Having abnormal blood pressure levels, whether elevated or dropped, are sure warning signs of ill health, and checking for these abnormalities is an important step towards the prevention of hypertension, stroke, or heart attack. Therefore, households as much as clinics and hospitals should invest in good quality sphygmomanometers for frequent use. Below is a list of the relevant factors one should consider before choosing what sphygmomanometer to purchase.
The right sphygmomanometer is determined by the needs and requirements of its user. Aneroid sphygmomanometers provide readings of high accuracy but require sufficient knowledge and expertise of handling the device. Nurses, physicians, and specialists should, therefore, look for durable, flexible, and high-accuracy devices such as these, that can withstand heavy use. Individuals looking to buy sphygmomanometers for personal use, meanwhile, may consider purchasing sphygmomanometers that are easiest to operate among the many varieties. Digital sphygmomanometers are designed to be very user-friendly, especially for those who do not have any medical background. Price is another determining factor for what sphygmomanometer to purchase, and the allocated budget can highly narrow down one’s decision. The price range of a decent sphygmomanometer varies from 10 to 70 dollars, depending on the type. Devices that fall in the higher price ranges are those designed for specialists who require high-performing instruments.
As with any medical instrument, the accuracy of measurements is of utmost importance. As discussed earlier, the accuracy of sphygmomanometers largely depends on its type–mercury sphygmomanometers provide the standard of measurements and is therefore of highest accuracy; aneroid sphygmomanometers also provide readings of very high accuracy, but require sufficient knowledge and expertise of handling the device; digital sphygmomanometers tend to sacrifice convenience and ease of use for accuracy of measurements, compared to the other two sphygmomanometer types.
Sphygmomanometers vary according to their quality of material and design, all of which affect the overall performance of the device. Therefore, all parts of a sphygmomanometer should be of top-notch quality. The cuff material, gauge, inflation bulb, and valve should all ideally be well constructed, non-sticking, and hypoallergenic. An ideal gauge should have 300 mmHg of pressure, and the bulb part should be made out of latex-free material. For a sphygmomanometer, cuff size is also extremely important. Cuff sizes that are either too loose- or tight-fit might result in incorrect readings. Therefore, one must make sure that the width of the sphygmomanometer cuff provides a size range that can fit its user perfectly, whether for personal or clinical use. For reference, 80% of the arm should be covered by the air bladder of the cuff. Small cuff sizes are for arm diameters of 17 to 22 cm, medium cuff sizes are for 22 to 32 cm, and large cuff sizes are for 33 to 42 cm arm diameters. For medical professionals, it is advised to purchase a medium-sized cuff that can be adjusted to fit patients’ larger and smaller sizes.
Sphygmomanometers, whether used frequently and in different places or bought for home use, should be evaluated based on convenience and ease of use. Physicians who need an instrument that can keep up with the busy work schedules that bring them to different places should purchase a sphygmomanometer that is lightweight and easy to carry. Those who are looking to buy a sphygmomanometer specifically for home use can opt to save a few bucks and choose a device that does not need to be lightweight or pocket-sized.
[amazon box=”B01FV10IFY” title=”White Coat Deluxe Aneroid Sphygmomanometer” link_title=”White Coat Deluxe Aneroid Sphygmomanometer” description=”Product Specifications: + 300mmHg no-pin stop + Aluminum alloy manometer + Classic Black nylon cuff + 2-tube adult size PVC bladder + Large Air-release valve + Taper end valve + Carrying case included + DEHP-Free” link=”https://www.amazon.com/White-Coat-Sphygmomanometer-Professional-Stethoscope/dp/B01FV143YQ”]
The White Coat Deluxe Aneroid Sphygmomanometer is designed for medical professionals and professionals-in-training. Aneroid sphygmomanometers provide a quick and easy technique for acquiring blood pressure readings among patients. Because it is relatively cheap and easy to use, this product is also perfect for medical students. Available under 20 dollars, this product provides a compromise between quality and affordability. Additionally, the product package also includes a LED penlight and pupil gauge, making it an even more valuable deal.
4 out of 5
Aneroid sphygmomanometers are generally considered high accuracy instruments, as long as a proper protocol is followed for its maintenance. As an alternative to mercury sphygmomanometers, aneroid devices are the top choice.
4 out of 5
The instrument is made of high-quality aluminum alloy and is considered DEHP-free. The cuff is made of nylon, and the air release valve is large and of a taper-end design for easier manipulation. The purchase also comes with a LED penlight and a pupil gauge for other medical check-up processes. The nylon cuff comes in an adjustable adult-sized cuff, so its fit might be limited.
3 out of 5
The White Coat Deluxe Aneroid Sphygmomanometer is an instrument that can be used on the go. Because of its lightweight nature, the instrument can easily be brought anywhere in its black carrying case.
5 out of 5
The instrument is a recommended purchase for doctors, nurses, and medical students looking for a sphygmomanometer that they can bring anywhere, around hospitals, and on the go, but also one that they can rely on to give accurate readings at a relatively low price.
[amazon box=”B00LV74908″ title=”MDF Calibra Aneroid Sphygmomanometer” link_title=”MDF Calibra Aneroid Sphygmomanometer” description=”•FREE MDF Single Head Stethoscope (MDF72710) with your MDF Sphygmomanometer purchase. “Add Both To Cart“ (discount applied at checkout). See details in the Special Offers section below. TRUSTED by Medical Providers since 1971 | Backed by our New Full Lifetime Warranty & Free-Parts-For-Life | Latex-Free | Adult Sized Cuff Included GAUGE: easy to read, extra-large high-contrast dial, stress-tested over 3,000 times, calibrated five times, and certified 300 mmHg manometer attains the accuracy of +/- 3 mmHg without pin stop. CUFF and CARRYING CASE: adult-sized cuff, high-molecular polymer nylon cuff, and carrying case are abrasion and moisture resistant. Accurate arterial compression with artery indicator label and index range. Removable bladder for easy cuff cleaning. INFLATION: high-density non-stick, non-cracking inflation bulb and bladder. Equipped with screw-type valve for easy and precise deflation control.” link=”https://www.amazon.com/MDF%C2%AE-Calibra-Aneroid-Sphygmomanometer-Pressure/dp/B00LV4W7E6″]
MDF Calibra Aneroid Sphygmomanometer is considered the best product available on the market right now. A quality product made for professionals, the instrument requires some assembling upon purchase. The MDF Calibra Aneroid Sphygmomanometer costs around 30 dollars, and with this relatively low price, the device comes with 3 years warranty and a lifetime offer of calibration.
5 out of 5
Aneroid sphygmomanometers are generally considered high accuracy instruments, as long as a proper protocol is followed for its maintenance. As an alternative to mercury sphygmomanometers, aneroid devices are the top choice.
4 out of 5
The MDF Calibra offers a top-quality inflation bladder and bulb made of safe, latex-free material. It has a large high-contrast gauge that provides uncomplicated readings, as well as an artery indicator lab, index range, and a very comfortable cuff made of high-molecular polymer nylon. Its high-density inflation bulb and bladder come with a chrome-plated brass screw valve. The MDF Calibra’s most distinctive feature is that it is a hand-crafted product. The instrument also comes with an adult-sized cuff stress-tested 3,000 times and calibrated five times.
3 out of 5
It is a portable device that you can easily carry around with you. The carrying case included in the purchase, along with the whole instrument, is also resistant to abrasion and moisture, which makes for a high-quality instrument that can withstand frequent use and wear-and-tear.
5 out of 5
The MDF Calibra is a well-tested brand that offers accuracy and quality sphygmomanometer parts at a relatively inexpensive cost. The flexibility of this sphygmomanometer design makes it a perfect tool for doctors, nurses, and other medical professionals, as well as medical students learning the techniques of the field.
[amazon box=”B06XCMK9WD” title=” Balance Sphygmomanometer” link_title=” Balance Sphygmomanometer” description=” THE RIGHT CHOICE: Thoughtfully made for clinical use or a classic approach to at-home monitoring. THE FEATURES YOU NEED Easy-to-read dial & comfortable, adjustable cuff. See Product Description. MADE THE RIGHT WAY: Your purchase should have a positive impact on all the people involved. BACKED BY REAL SUPPORT: The friendly team at our St. Louis headquarters is here for whatever you need. (Covered by 2-Year Warranty)” link=”https://www.amazon.com/Sphygmomanometer-Pressure-Monitor-Balance-Stethoscope/dp/B06XCMK9WD/ref=cm_cr_arp_d_bdcrb_top?ie=UTF8″]
Made for both clinical use and at-home health monitoring, the Balance Sphygmomanometer offers a quality instrument at an affordable price of under 25 dollars. The aesthetically-designed product also comes with a 2-year warranty.
4 out of 5
Aneroid sphygmomanometers are generally considered high accuracy instruments, as long as a proper protocol is followed for its maintenance. As an alternative to mercury sphygmomanometers, aneroid devices are the top choice. The Balance Sphygmomanometer has been deemed accurate within 3 mmHg.
4 out of 5
One of the best features of the Balance Sphygmomanometer is its streamlined design, combining the bulb, dial, and air valve in one complete component for easier handling and use. The dial and overall color scheme were also updated to become easier on the eyes, and the healthy range for blood pressure readings on the dial was emphasized for quicker visual analysis. In addition, the cuff is lined with soft fabric and adjustable for adult arm sizes of 8.75 to 16.5 inches. The cuff also comes with an artery indicator and D-ring for a more convenient fitting process on the arm.
4 out of 5
The Balance Sphygmomanometer succeeds in making an easy-to-use device with its combined components of the bulb, dial, and air valve. This design makes it easier to take blood pressure readings of one’s own body. It also comes with a storage case for easy carry, and the overall structural design makes for a less cluttered instrument, making it easy to bring it around and whip it out for quick blood pressure measurements at home, at the clinic, or out in the field.
4 out of 5
The Balance Sphygmomanometer is a great instrument for anybody with a need to take blood pressure readings. Its aesthetic, easy-to-use, and easy-to-read design, along with reliable and highly-accurate measurements make it a great bargain. The instruments simplify blood pressure measurement in any context.
[amazon box=”B01MG5V9UL” title=”Paramed Aneroid Sphygmomanometer with Single Head Stethoscope and Carrying Case” link_title=” Paramed Aneroid Sphygmomanometer with Single Head Stethoscope and Carrying Case” description=”•Long cuff (22-42cm) suitable for any arm size •Large number dial with contrasting numbers •Improved pressure blower check valve •Clinically calibrated for highly accurate readings •Durable, metal monitor body •Comfortable, Velcro strip •Special gauze filter to prevent dust •Medical grade, single head stethoscope with hypoallergenic tubes •Neatly packed in a portable, nylon pouch for safe storage and easy transport •Backed by a hassle-free, 30 day money back guarantee” link=”https://www.amazon.com/PARAMED-Aneroid-Sphygmomanometer-Stethoscope-Universal/dp/B01FI5AM36″]
The Paramed Aneroid Sphygmomanometer is a premium quality instrument perfect for home use. It is available for around 30 dollars, stethoscope and carrying case included, making it the ultimate purchase for those dealing with hypertensive symptoms who would like to monitor their health without the frequent need for doctor visits. Given its accuracy, the Paramed Aneroid Sphygmomanometer can also be a great tool for doctors, nurses, and other medical practitioners.
5 out of 5
Aneroid sphygmomanometers are generally considered high accuracy instruments, as long as a proper protocol is followed for its maintenance. As an alternative to mercury sphygmomanometers, aneroid devices are the top choice.
4 out of 5
The Paramed Aneroid Sphygmomanometer is made out of premium quality material which consists of super sensitive polymer remembrances and hypoallergenic PVC tubes. Because of its design, the instrument is easy to use for both left and right-handed people with a simple flip of the dial. Similar to other sphygmomanometer designs, the Paramed Sphygmomanometer also combines the bulb, dial, and valve in a single handful for easy manipulation and self-examination. It has a long, comfortable, wear-proof nylon cuff of 22 to 42 cm fitted with a comfortable velcro strip.
5 out of 5
This purchase includes a complete blood pressure kit, with a manual cuff and a single head stethoscope. This Sphygmomanometer by Paramed is an excellent gadget for every home. It can track your blood pressure easily and accurately, anywhere at any time. It is a lightweight, portable device.
5 out of 5
This sphygmomanometer type is perfect for home and personal use, because of its simplicity and high accuracy measurements. The best feature of the Paramed sphygmomanometer is the convenient manual manipulation through the combined bulb, dial, and valve, and alterable orientations for both left-handed and right-handed individuals.
[amazon box=”B004D9P1A8″ title=” Omron 7 Series Wrist Blood Pressure Monitor (100 Reading Memory)” link_title=” Omron 7 Series Wrist Blood Pressure Monitor (100 Reading Memory)” description=” Automatically inflates when the wrist is at heart level and indicator lights make it easier to find the correct position. Silent and quick inflation, so measurements can be taken quietly anywhere, anytime, and even more discretely. The blood pressure level bar shows how your reading compares to the internationally recognized guidelines for normal blood pressure levels. The slim design is discreet, convenient, and portable so you can take measurements when you need to. An irregular heartbeat detector detects and alerts you of irregular heartbeats while your blood pressure is being measured. Advanced Averaging technology displays the average of the last three readings in 10 minutes. 100 Memory storage with date and time stamp allows you to review the last 100 readings with a touch of a button. Fits wrists sized 5 1/4“ to 8 1/2“ in circumference.” link=”https://www.amazon.com/Omron-Pressure-Monitor-Reading-Memory/dp/B004D9P1A8/ref=cm_cr_arp_d_product_top?ie=UTF8″]
Digital sphygmomanometers have become quite popular, not only for personal use at home but also in hospitals. A number of high-quality sphygmomanometers are available in the market, but among these, Omron 7 series is considered the best. Aside from the blood pressure measurement through the wrist, there are also a number of other useful features including a hypertension indicator, irregular heartbeat indicator, advanced averaging technology, blood pressure level bar, and digital data storage with date and time stamps. Digital devices are sold at higher price ranges because of the convenience they offer, but for Omron 6 series at around 50 dollars, it is sure to be a successful compromise.
3 out of 5
Out of the three sphygmomanometer types, the digital sphygmomanometer offers the least accuracy, but still of an arguable clinical standard. Even so, the Omron 7 Series is the most recommended brand by doctors and pharmacists for clinically-accurate home blood pressure monitoring. When worn, its Heart Zone Guidance program allows for consistently accurate readings by measuring blood pressure each time the arm is at heart level.
4 out of 5
From a quality and design standpoint, it is a great device that is quite easy to use. It stores and reviews the last 100 readings with date and time stamps. It is a durable and long-lasting product, excellent for use at home. The Omron 7 Series is a highly recommended product for home use, and it comes with a comfortably-designed cuff fitted onto one’s wrist, that one can adjust according to your own requirement. In addition, the instrument is equipped with ultra-silent inflation capabilities so that one can use the device in any setting without too much noise and hassle.
5 out of 5
The Omron 7 Series is a portable device that patients and users can wear anywhere. It has a sensor that is automatically activated whenever the wrist is raised at heart level, while a blue light gives an alert notification before it takes the reading. The instrument has many value-added features, and it is overall a great product for personal use at home and even outdoors, due to its battery-powered design.
5 out of 5
For normal individuals who would like the convenience of measuring blood pressure readings virtually anytime and anywhere, the Omron 7 Series is a perfect choice. Recommended by doctors and other healthcare practitioners, it is an easy-to-use gadget that provides clinical-level accuracy. This design addresses the need for effective and convenient health monitoring at home.
[amazon box=”B00N9I63PG” title=” Balance Professional Upper Arm Blood Pressure Monitor” link_title=”Balance Professional Upper Arm Blood Pressure Monitor” description=”Highly Rated: More than 85% 4 star and 5-star reviews Popular Item: Popular with customers shopping for “xl blood pressure cuff“ Prime Delivery: Eligible for Prime free, fast delivery” link=”https://www.amazon.com/Greater-Goods-Pressure-Monitor-Balance/dp/B00N9I63PG”]
If you are looking for a digital sphygmomanometer with a manual pressure cuff, then Balance Professional Upper Arm BP Monitor is the best go-to option for you. Digital sphygmomanometers are of more expensive price ranges than other sphygmomanometer types, but the Balance Professional Pressure Monitor is available at a very reasonable price. The highly-technological device can measure systolic and diastolic blood pressure, as well as pulse, with a single push of the button. Since it is a digital device, it may not be as long-lasting as aneroid sphygmomanometers, but its purchase comes with a two-year warranty.
4 out of 5
Out of the three sphygmomanometer types, the digital sphygmomanometer offers the least accuracy, but still of an arguable clinical standard. However, the Balance Upper Arm Blood Pressure Monitor still succeeds in offering highly accurate readings in the home context.
4 out of 5
The Balance Professional Upper Arm Blood Pressure Monitor is one of the most sought-after premium digital sphygmomanometers available in the market. It has a simple and easily adjustable upper arm cuff. It is a one-size-fits-most cuff, which means you can adjust to any arm size. The readings will display on the screen when you push the button, and 2 users can store up to 60 records each. Another great feature of this device is that it automatically switches off, providing battery-saving qualities.
4 out of 5
Like most digital sphygmomanometers, the Balance Upper Arm Blood Pressure Monitor is a portable and easy-to-carry device. The product comes with two power sources–a power cord and AAA batteries. The kit includes a case for convenient storage.
4 out of 5
With its large LCD and buttons that are easy to navigate, the Balance Professional Upper Arm Blood Pressure Monitor is perfect for home use. It is recommended for households to have a reliable blood pressure instrument at home, for regular use and emergencies.
A sphygmomanometer is an extremely important medical apparatus used for monitoring and evaluating an individual’s blood pressure and overall health. Therefore, it should give quick and accurate readings every time. The market is filled with all types of sphygmomanometers with different designs, types, prices, and brands, making it difficult to select the right one. Our sphygmomanometer buying guide provides you with all the required information to choose the best sphygmomanometer for you, whatever you might use it for. The sphygmomanometers mentioned in our list are some of the best devices available in the market.
In behavioral neuroscience, the Open Field Test (OFT) remains one of the most widely used assays to evaluate rodent models of affect, cognition, and motivation. It provides a non-invasive framework for examining how animals respond to novelty, stress, and pharmacological or environmental manipulations. Among the test’s core metrics, the percentage of time spent in the center zone offers a uniquely normalized and sensitive measure of an animal’s emotional reactivity and willingness to engage with a potentially risky environment.
This metric is calculated as the proportion of time spent in the central area of the arena—typically the inner 25%—relative to the entire session duration. By normalizing this value, researchers gain a behaviorally informative variable that is resilient to fluctuations in session length or overall movement levels. This makes it especially valuable in comparative analyses, longitudinal monitoring, and cross-model validation.
Unlike raw center duration, which can be affected by trial design inconsistencies, the percentage-based measure enables clearer comparisons across animals, treatments, and conditions. It plays a key role in identifying trait anxiety, avoidance behavior, risk-taking tendencies, and environmental adaptation, making it indispensable in both basic and translational research contexts.
Whereas simple center duration provides absolute time, the percentage-based metric introduces greater interpretability and reproducibility, especially when comparing different animal models, treatment conditions, or experimental setups. It is particularly effective for quantifying avoidance behaviors, risk assessment strategies, and trait anxiety profiles in both acute and longitudinal designs.
This metric reflects the relative amount of time an animal chooses to spend in the open, exposed portion of the arena—typically defined as the inner 25% of a square or circular enclosure. Because rodents innately prefer the periphery (thigmotaxis), time in the center is inversely associated with anxiety-like behavior. As such, this percentage is considered a sensitive, normalized index of:
Critically, because this metric is normalized by session duration, it accommodates variability in activity levels or testing conditions. This makes it especially suitable for comparing across individuals, treatment groups, or timepoints in longitudinal studies.
A high percentage of center time indicates reduced anxiety, increased novelty-seeking, or pharmacological modulation (e.g., anxiolysis). Conversely, a low percentage suggests emotional inhibition, behavioral avoidance, or contextual hypervigilance. reduced anxiety, increased novelty-seeking, or pharmacological modulation (e.g., anxiolysis). Conversely, a low percentage suggests emotional inhibition, behavioral avoidance, or contextual hypervigilance.
The percentage of center time is one of the most direct, unconditioned readouts of anxiety-like behavior in rodents. It is frequently reduced in models of PTSD, chronic stress, or early-life adversity, where animals exhibit persistent avoidance of the center due to heightened emotional reactivity. This metric can also distinguish between acute anxiety responses and enduring trait anxiety, especially in longitudinal or developmental studies. Its normalized nature makes it ideal for comparing across cohorts with variable locomotor profiles, helping researchers detect true affective changes rather than activity-based confounds.
Rodents that spend more time in the center zone typically exhibit broader and more flexible exploration strategies. This behavior reflects not only reduced anxiety but also cognitive engagement and environmental curiosity. High center percentage is associated with robust spatial learning, attentional scanning, and memory encoding functions, supported by coordinated activation in the prefrontal cortex, hippocampus, and basal forebrain. In contrast, reduced center engagement may signal spatial rigidity, attentional narrowing, or cognitive withdrawal, particularly in models of neurodegeneration or aging.
The open field test remains one of the most widely accepted platforms for testing anxiolytic and psychotropic drugs. The percentage of center time reliably increases following administration of anxiolytic agents such as benzodiazepines, SSRIs, and GABA-A receptor agonists. This metric serves as a sensitive and reproducible endpoint in preclinical dose-finding studies, mechanistic pharmacology, and compound screening pipelines. It also aids in differentiating true anxiolytic effects from sedation or motor suppression by integrating with other behavioral parameters like distance traveled and entry count (Prut & Belzung, 2003).
Sex-based differences in emotional regulation often manifest in open field behavior, with female rodents generally exhibiting higher variability in center zone metrics due to hormonal cycling. For example, estrogen has been shown to facilitate exploratory behavior and increase center occupancy, while progesterone and stress-induced corticosterone often reduce it. Studies involving gonadectomy, hormone replacement, or sex-specific genetic knockouts use this metric to quantify the impact of endocrine factors on anxiety and exploratory behavior. As such, it remains a vital tool for dissecting sex-dependent neurobehavioral dynamics.
The percentage of center time is one of the most direct, unconditioned readouts of anxiety-like behavior in rodents. It is frequently reduced in models of PTSD, chronic stress, or early-life adversity. Because it is normalized, this metric is especially helpful for distinguishing between genuine avoidance and low general activity.
Environmental Control: Uniformity in environmental conditions is essential. Lighting should be evenly diffused to avoid shadow bias, and noise should be minimized to prevent stress-induced variability. The arena must be cleaned between trials using odor-neutral solutions to eliminate scent trails or pheromone cues that may affect zone preference. Any variation in these conditions can introduce systematic bias in center zone behavior. Use consistent definitions of the center zone (commonly 25% of total area) to allow valid comparisons. Software-based segmentation enhances spatial precision.
Evaluating how center time evolves across the duration of a session—divided into early, middle, and late thirds—provides insight into behavioral transitions and adaptive responses. Animals may begin by avoiding the center, only to gradually increase center time as they habituate to the environment. Conversely, persistently low center time across the session can signal prolonged anxiety, fear generalization, or a trait-like avoidance phenotype.
To validate the significance of center time percentage, it should be examined alongside results from other anxiety-related tests such as the Elevated Plus Maze, Light-Dark Box, or Novelty Suppressed Feeding. Concordance across paradigms supports the reliability of center time as a trait marker, while discordance may indicate task-specific reactivity or behavioral dissociation.
When paired with high-resolution scoring of behavioral events such as rearing, grooming, defecation, or immobility, center time offers a richer view of the animal’s internal state. For example, an animal that spends substantial time in the center while grooming may be coping with mild stress, while another that remains immobile in the periphery may be experiencing more severe anxiety. Microstructure analysis aids in decoding the complexity behind spatial behavior.
Animals naturally vary in their exploratory style. By analyzing percentage of center time across subjects, researchers can identify behavioral subgroups—such as consistently bold individuals who frequently explore the center versus cautious animals that remain along the periphery. These classifications can be used to examine predictors of drug response, resilience to stress, or vulnerability to neuropsychiatric disorders.
In studies with large cohorts or multiple behavioral variables, machine learning techniques such as hierarchical clustering or principal component analysis can incorporate center time percentage to discover novel phenotypic groupings. These data-driven approaches help uncover latent dimensions of behavior that may not be visible through univariate analyses alone.
Total locomotion helps contextualize center time. Low percentage values in animals with minimal movement may reflect sedation or fatigue, while similar values in high-mobility subjects suggest deliberate avoidance. This metric helps distinguish emotional versus motor causes of low center engagement.
This measure indicates how often the animal initiates exploration of the center zone. When combined with percentage of time, it differentiates between frequent but brief visits (indicative of anxiety or impulsivity) versus fewer but sustained center engagements (suggesting comfort and behavioral confidence).
The delay before the first center entry reflects initial threat appraisal. Longer latencies may be associated with heightened fear or low motivation, while shorter latencies are typically linked to exploratory drive or low anxiety.
Time spent hugging the walls offers a spatial counterbalance to center metrics. High thigmotaxis and low center time jointly support an interpretation of strong avoidance behavior. This inverse relationship helps triangulate affective and motivational states.
By expressing center zone activity as a proportion of total trial time, researchers gain a metric that is resistant to session variability and more readily comparable across time, treatment, and model conditions. This normalized measure enhances reproducibility and statistical power, particularly in multi-cohort or cross-laboratory designs.
For experimental designs aimed at assessing anxiety, exploratory strategy, or affective state, the percentage of time spent in the center offers one of the most robust and interpretable measures available in the Open Field Test.
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