cuanto cuesta una vaca viva

13840110d2d515487e83b87 disadvantages of using rats in research

This problem can be overcome by restraining the rodent and only placing the plantar surface of a one hind paw on the metal surface and recording the time to withdrawal, however this method requires significant handling and associated stress (Menndez et al., 2002). In contrast to other Von Frey setups, animals are housed in individual enclosures with bars, rather than mesh, to help maximize the surface area of the hind paw available for application of the filament. Exp. However, theyre more widely used in studying cardiovascular and metabolic disorders, as well as the onset of conditions that relate to the brain, digestive system, and various health problems related to behavior. For detailed protocols of these methods see Minett et al. With the sequencing of the Brown Norway rat in 2004 by the Rat Genome Sequencing Project Consortium, led by the Baylor College of Medicine, it is now known that almost all disease-linked human genes have counterparts in the rat. A disadvantage of this method is that the number of measurements per animal is variable and that it requires repeated, time-intensive measurements, which may lead to sensitization or learnt responses. Rep. 7:40883. doi: 10.1038/srep40883, Deuis, J. R., Yin, K., Cooper, M. A., Schroder, K., and Vetter, I. Scientists often cite the similarities between animals and humans as the rationale for animal experimentation. doi: 10.1177/0023677214559084, Minett, M. S., Eijkelkamp, N., and Wood, J. N. (2014). 1981. The burrows are placed in the rodents cage for a pre-determined duration and the amount of material displaced is weighed and recorded (Deacon, 2006b; Jirkof et al., 2010). 101, 457464. Rep. 5:14648. doi: 10.1038/srep14648. Experimenters experienced in the technique are able to distinguish between touch on or false positive responses, however, this can be difficult for inexperienced researchers and extensive training is usually required to produce high quality data. 1, 28282830. doi: 10.1038/nmeth.1455, Leith, J. L., Koutsikou, S., Lumb, B. M., and Apps, R. (2010). This work was supported by an Australian Research Council Future Fellowship (IV). Pain 7:55. doi: 10.1186/1744-8069-7-55, Tappe-Theodor, A., and Kuner, R. (2014). (2014). It is the premier source of information on the laboratory rat. As many animal models of pain using stimulus-evoked measures of nociception have failed in the past to translate into the clinic, spontaneous pain as an efficacy endpoint may be more relevant to the human condition and increase the clinical validity of animal models of pain in the future (Mogil, 2009). J. (2009). New hot plate tests to quantify antinociceptive and narcotic antagonist activities. Animal Testing | Pros & Cons | ProCon.org Ethical Considerations in Mouse Experiments - PubMed A touch-on reaction is more likely to occur if the filament is not applied perpendicularly, if the filament is not applied smoothly, or if the filament moves horizontally during application, inducing scratching. doi: 10.1080/23328940.2015.1135689, Vazquez, G., Alvarez, E., and Navaza, J. M. (1995). 120, 37603772. Pain 22, 131. The thermal probe test: a novel behavioral assay to quantify thermal paw withdrawal thresholds in mice. In unilateral pain models, many changes in gait parameters are observed, including reduced intensity (paw pressure), reduced print area, reduced stance phase duration (time spent on paw), increased swing phase duration (time spent off paw) in the ipsilateral hind paw compared to contralateral hind paw, consistent with reduced weight bearing and guarding behaviors (Parvathy and Masocha, 2013; Yin et al., 2016). Rodents are placed individually in small enclosures with a glass floor. Orbital tightening is the narrowing of the orbital area and tightly closing or squeezing of eyes. Despite these advantages of automation, experimenters still need to be experienced to distinguish true responses from touch-on responses and ambulation. Sci. One way to evaluate nociception in non-communicating subjects is through observation of behavior. The mouse genome is very similar to our own, making mouse genetic research particularly useful for the study of human diseases. Assoc. Pain 154, 19992006. However, while application of the ice pellet to the glass generates a cooling ramp that can be approximately correlated to estimates of the paw withdrawal temperature, the paw being tested needs to remain in contact with the glass to achieve efficient temperature transfer. Am. The advantage of this approach is that each animal receives the same number and type of stimuli, although the number of tests per hind paw could exceed 50 (e.g., five different von Frey filaments each applied 10 times), which is not only time consuming, but potentially exposes animals with mechanical hind paw sensitivity to a disproportionate number of more aversive stimuli. doi: 10.1016/s0304-3959(00)00307-9, Kim, S. H., and Chung, J. M. (1992). (A) Grimace scales. (1989). Both instruments have been validated against manual von Frey filaments and found to produce less variable data in addition to being easier to use. (A) The up-down method. The Hargreaves test permits measurement of ipsilateral and contralateral heat thresholds, allowing each animal to serve as its own internal control in unilateral pain models. J. Neurosci. Nocifensive behaviors include forepaw withdrawal or licking, hind paw withdrawal or licking, stamping, leaning posture and jumping (Espejo and Mir, 1993). Automated analysis of postoperative behaviour: assessment of HomeCageScan as a novel method to rapidly identify pain and analgesic effects in mice. While generally not an issue in rats, which are reported to only require 5 min of habituation (Hargreaves et al., 1988), the habituation time in mice is often reported to be 30 min or longer (Harvey and Dickenson, 2009; Guilford et al., 2011; OBrien et al., 2013), precluding testing of compounds with short duration of action or pain models of limited duration. You want to survey as large a sample size as possible; the larger the standard deviation, the less accurate your results might be, since smaller sample sizes get decreasingly representative of the entire population. The amount of substrate displaced over a set period of time is recorded. Randall, L. O., and Selitto, J. J. This normally protective response, which is absent in these individuals, leads to frequent injuries and often results in higher mortality rates early in life (Bennett and Woods, 2014). Neurosci. Neuropathic pain: aetiology, symptoms, mechanisms, and management. J. Pharmacol. Lett. Similarly, if a stimulus is applied that does normally evoke a withdrawal response, but the animal withdraws with an exaggerated response, the animal is considered to have hyperalgesia. Sci. Twitter Pain 5:18. doi: 10.1186/1744-8069-5-18, Hirst, J. Why use the mouse in research? - YourGenome The intensity of the light source should be adjusted to produce withdrawal latencies of 1012 s in nave animals, providing a sufficient window to detect heat allodynia and hypoalgesia, with a pre-determined cut off time to prevent tissue damage. [ 1] [ 2] [ 3] 2. Rats are often used to study behaviour in psychology experiments. The 50% threshold is then calculated using the formula: 50% threshold (g) = 10(X+kd)/104, where X = the value (in log units) of the final von Frey filament, k = tabular value for the response pattern (see Appendix 1 in Chaplan et al., 1994) and d = the average increment (in log units) between von Frey filaments. However mice are less likely to survive the hypoxia-ischemia procedure, display a wider variety of brain damage, and have dramatic strain-to-strain differences. doi: 10.1371/journal.pone.0175839, Han, J. S., Bird, G. C., Li, W., Jones, J., and Neugebauer, V. (2005). And more precise technologies have become available as well, such as using CRISPR to targeting rat spermatogonial stem cells. Repeated exposure to sham testing procedures reduces reflex withdrawal and hot-plate latencies: attenuation of tonic descending inhibition? A camera below records the paw prints, which are illuminated by internally reflected light in the glass. Mol. Annu. - Quora Answer: I'm going to answer this purely from the point of view of toxicology studies, because that's where my experience is. While rats tend the habituate quickly (<15 min), mice can take up to an hour or more to settle in the cage before testing can begin, which can be time consuming (Chaplan et al., 1994; Minett et al., 2011). Development of the Rodent Face Finder, which captures stills of rodent faces that a researcher then scores according to the relevant scale, has automated some of the experimental process (Sotocinal et al., 2011) albeit development of automatic facial expression scoring will make this approach even more widely useful. The time taken to withdraw from the heat stimulus is recorded as the withdrawal latency, and depending on the model of the Hargreaves apparatus, may either be recorded manually by the investigator or automatically by the apparatus. Although expensive to produce and not always precise, this became the preferred method to target rats in a specific manner. The test begins by assessing the response to a filament estimated to be close to the 50% withdrawal threshold (in this case 1 grams-force). Brain Res. Figure 2.Visual representation of the different methodological approaches used to determine mechanical sensitivity using manual Von Frey. (C) Weight bearing (incapacitance test). Ishikawa, G., Nagakura, Y., Takeshita, N., and Shimizu, Y. Pain 3:40. doi: 10.1186/1744-8069-3-40, Pitcher, G. M., Ritchie, J., and Henry, J. L. (1999). Pain 22, 130136. Three main ethical attitudes towards animals are reviewed here. Temperature 3, 7791. Nevertheless, the temperature preference test has been used extensively in the study of the role of thermosensitive transient receptor potential (TRP) channels in thermal nociception including TRPA1, TRPM8, TRPM3, TRPV3 and TRPV4 (Bautista et al., 2007; Knowlton et al., 2010; Huang et al., 2011; Vriens et al., 2011; Touska et al., 2016). In recent years mice have been used with increasing frequency, to take advantage of genetically modified lines as well as the relatively lower costs compared with rats. (2011). (2015). Sensory determinants of thermal pain. Different methodological approaches are used to determine mechanical sensitivity using manual Von Frey, including the up-down, ascending stimulus or percent response method, all of which will be discussed below. Exp. (A) Acetone evaporation test. 1020, 215221. This shift was primarily instigated by the availability of a much . J. Vis. Ther. (2017b). Sci. Eur. Email: inquiry@genetargeting.com In its simplest form, the animal can choose between two adjacent areas maintained at different temperatures. However, in practice it is difficult to distinguish between allodynia and hyperalgesia in animals, and the terms allodynia and hyperalgesia are often used incorrectly or interchangeably in the literature. Readership. Using the horse grimace scale (HGS) to assess pain associated with acute laminitis in horses (Equus caballus). The laboratory rat, Rattus norvegicus, has been used in biomedical research for more than 150 years, and in many cases remains the model of choice for studies of physiology, behavior, and complex human disease. The rats ability to learn, remember, and interact gives them an advantage over other species, allowing for insights into the basic principles behind learning and behavior which can then be translated to human behavior and learning. Typically, the sensation of warm is elicited at temperatures of 3437C, while the sensation of pain is elicited at temperatures of 4248C (Pertovaara et al., 1996; Defrin et al., 2006; Rolke et al., 2006). However, with the use of animal models come challenges relating to the appropriate quantification of behavioral responses that could be considered equivalent to pain in humans. In human patients, a distinction is made between stimulus-evoked pain and stimulus-independent or spontaneous pain. Mouse Biol. The Disadvantages of a Small Sample Size | Sciencing In a 1926 letter to Nature, Selye described the findings of a series of experiments on rats, in which the animals were subjected to numerous stressors, which he referred to as "nocuous agents . Why we use rodents to research the brain - San Diego Union-Tribune Abstract The laboratory rat was the first mammal domesticated for research purposes. This suggests that the tail flick response may be impacted by changes in motor processing (Chapman et al., 1985). (2005). Some results suggest that the rat more accurately reflects human physiology than other species, mimicking human disease more accurately in many cases. Variability is determined by the standard deviation of the population; the standard deviation of a sample is how the far the true results of the survey might be from the results of the sample that you collected. The term cerebral palsy denotes a highly variable syndrome affecting up to 3 out of every 1000 children born. A disadvantage of the Hargreaves test is that the paw withdrawal time is recorded rather than directly measuring the paw withdrawal temperature. Similarities in pain descriptions of four different ethnic-culture groups. The rodent is placed in an inclined holder with the hind paws resting on two separate pressure sensors. doi: 10.1016/j.physbeh.2011.05.015, Tjolsen, A., Rosland, J. H., Berge, O. G., and Hole, K. (1991). Advantages and Disadvantages of Using Small and Large Animals in Burn Other advantages of this methodology include eliminating the phenomenon of clustered selection and a low . doi: 10.1016/0165-0270(94)90144-9, Chapman, C. R., Casey, K. L., Dubner, R., Foley, K. M., Gracely, R. H., and Reading, A. E. (1985). Therefore, there is an urgent need to increase our understanding of the underlying mechanisms of pain and to develop new treatments. Several commercial automated gait analysis systems have been developed, including the CatWalk XT (Noldus) and GaitLab (ViewPoint Behavior Technology), which use internally reflected light to illuminate paw prints as an animal walks across an elevated glass floor (Figure 6D), and DigiGait (Mouse Specifics Inc.) and GaitScan/TreadScan (CleverSys), which use video recordings and automated software to analyze paw prints of animals walking on a transparent belt treadmill or clear floor walkway (Berryman et al., 2009; Parvathy and Masocha, 2013; Adams et al., 2016). In mice, ES cells can be maintained in their pluripotent state easily. Typically, the experimental setup consists of a test plate at a fixed temperature (usually between 5C and 55C) that is placed adjacent to a reference plate at neutral temperature (usually between 25C and 30C; Figure 5A). Pain 150, 340350. Appreciation that the human pain experience encompasses multiple stimulus modalities, distinct molecular mechanisms and sensory, motor, vegetative, emotional, motivational components should highlight the need for carefully designed experiments that take this complexity into consideration. The historic struggle against pathogens of laboratory rodents is often divided into three periods. Lancet 353, 19591964. Thus, the term nociception is used to describe the peripheral neuronal response to noxious stimuli, which encompasses any stimuli, being mechanical, thermal, electrical or chemical, that have the potential to damage are damaging to tissue (Dubin and Patapoutian, 2010). doi: 10.1038/nprot.2006.19, Decosterd, I., and Woolf, C. J. TRPV3 and TRPV4 ion channels are not major contributors to mouse heat sensation. A., Possani, L. D., Cabot, P. J., Lewis, R. J., et al. 16 Integral Pros and Cons of Animal Experimentation Researchers are often advised to begin their studies using rat models in these areas, not only because they are a suitable model, but also due to the fact that rats have already helped scientists reach a few significant breakthroughs in these areas. Both the mouse and rat grimace scale are limited by the need for extensive training of the observer and a degree of subjectivity, which could lead to variability. Originally the method was used on rat pups seven days after birth, when their brains are most similar to those of newborn babies. With a much less expensive and more precise method for targeting genomes via embryos, the potential for rats as a model system of human disease could be pursued even easier. Then there is the Sprague Dawley, an outbred albino preferred for behavioral studies. Protoc. 95% of all animals used in research are rats because their genetic, biological and behavioral characteristics are so similar to that of humans. Data 40, 611614. Figure 1. doi: 10.1016/j.ejphar.2014.05.048, Jacobs, B. Y., Kloefkorn, H. E., and Allen, K. D. (2014). The response temperature is dependent on the starting temperature, ambient temperature and rate of heating, with faster heat ramps resulting in higher response temperatures (Tjolsen et al., 1991; Yalcin et al., 2009). TRPM8, but not TRPA1, is required for neural and behavioral responses to acute noxious cold temperatures and cold-mimetics in vivo. The Practical Mouse Despite the advantages rats have over mice as human analogs, mice have dominated the modern genetic and biomedical research landscape. Pain 68, 141150. The Natural History of Model Organisms: The Norway rat, from an - eLife J. Med. Nose bulge refers to the bulge noticeable on the bridge of the nose, whereas cheek bulge refers to the rounded projection of the cheek muscle compared to its typical appearance. The rat dies of other causes before tests can show the neurological damage that can be caused by long-term, low-dose exposure to gasoline. Methods 25, 241250. Cartil. 111, 409419. Lab. (1991). doi: 10.1016/0024-3205(85)90227-9. Behaviors tend to occur on a spectrum of intensity, but are usually scored in binary as either present or absent. If no nocifensive behaviors are observed, the animal must be removed from the hot plate after pre-determined cut-off time to prevent tissue damage. Assessing hoarding in mice. (B) Burrowing assay. An advantage of this method is that it avoids excessive application of Von Frey filaments that elicit aversive behaviors. Mouse model: Pros & Cons - SlideShare 24, 19281939. The principles that apply to mice generally apply to rats and other laboratory rodents, but species-specific differences in behaviour and size alter the specifics of handling procedures that work well in each species. A disadvantage of systems that only use video recordings (e.g., DigiGait, GaitScan/TreadScan) is that they cannot measure paw print intensity or pressure (weight bearing parameters), which is relevant for pain models. The first (1880-1950) was when mice and rats became common research animals. doi: 10.1016/s1474-4422(14)70024-9, Berge, O. G., Garcia-Cabrera, I., and Hole, K. (1988). In this assay rodents walk freely across an enclosed elevated glass floor. Rodents (especially Mus musculus and Rattus norvegicus) have been the most widely used models in biomedical research for many years. Xing, H., Chen, M., Ling, J., Tan, W., and Gu, J. G. (2007). Not only does your survey suffer due to timing, but the number of subjects does not help make up for this deficiency. Sci. Characterization of the foot withdrawal response to noxious radiant heat in the rat. (2003). Differentiating analgesic and non-analgesic drug activities on rat hot plate: effect of behavioral endpoint. If you post a survey on your kitchen cleaner website, then only a small number of people have access to or knowledge about your survey, and it is likely that those who do participate will do so because they feel strongly about the topic. Pain 123, 231243. ACS Chem. J. Neurosci. Methods 141, 261269. From a physiological standpoint, more is known about the responses and pathways in rats than in other species due to the wealth of data collected over the years. The burrowing assay has been validated for models of post-surgical pain in mice and in models of peripheral nerve injury, osteoarthritis and inflammation induced by CFA in rats (Jirkof et al., 2010; Andrews et al., 2012; Bryden et al., 2015). In terms of the diseases that they are used to study, rats are usually not the model of choice when it comes to disorders related to neoplasms, blood and immune function. It should be noted that no test can therefore measure pain in animals directlythe presumably unpleasant emotional experience of pain is inferred from pain-like behaviors which can include the withdrawal of a body part from a stimulus, reduced ambulation, agitation, an increase in grooming of the affected area, and vocalizations upon sensory stimulation. Rodent models in neuroscience research: is it a rat race? 25, 99111. doi: 10.1016/s0304-3959(00)00276-1, Defrin, R., Ohry, A., Blumen, N., and Urca, G. (2002). For example, paw licking is diminished by opioids but not other analgesics, while other behaviors can also be affected by other classes of analgesics (Ankier, 1974; Hunskaar et al., 1985). doi: 10.1016/j.jneumeth.2013.12.010, Bryden, L. A., Nicholson, J. R., Doods, H., and Pekcec, A. Exp. It should be noted that behavioral assessment of animals in groups (even if blinded) is typically not sufficient, with a preferred method being measurements performed on animals in random order by an investigator blinded to the treatment group each animal has been allocated to. This continues until at least four readings are obtained after the first change of direction. doi: 10.1111/ejn.12643, Tetreault, P., Dansereau, M. A., Dor-Savard, L., Beaudet, N., and Sarret, P. (2011). A modified version of the thermal probe test suitable for quantifying heat thresholds in rats is still to be developed. Animal studies in psychology - American Psychological Association J. Advantages Of Rat Models and Their Uses in Disease Research Third, aversive response to a cooling ramp can be used to determine the cold response threshold (Yalcin et al., 2009). Lab. The temperature preference is used as a surrogate measure of thermal aversion and aims to assess temperature preference in rodents. Handling and restraint: General principles | NC3Rs By comparing the frequencies of behaviors in animal models of pain as opposed to control states, inference about different pain states (and especially spontaneous nociception) can be made. Brain 125, 501510. doi: 10.1523/JNEUROSCI.1526-05.2005, Schtt, E., Berge, O. G., Angeby-Mller, K., Hammarstrm, G., Dalsgaard, C. J., and Brodin, E. (1994). doi: 10.1016/s0165-0270(99)00004-7, Plone, M. A., Emerich, D. F., and Lindner, M. D. (1996). Sci. These behavioral methods can be divided into stimulus-evoked or non-stimulus evoked (spontaneous) nociception, based on whether or not application of an external stimulus is used to elicit a withdrawal response. In humans, spontaneous or background pain is pain that occurs without an identifiable stimulus. doi: 10.1038/nprot.2006.171, Deacon, R. M. (2006b). McGrath, J. C., Drummond, G. B., McLachlan, E. M., Kilkenny, C., and Wainwright, C. L. (2010). Rodents are placed individually in a small cage with a barred floor. J. Pharmacol. Cerebral palsy. The same is likely to be true of other rodent species, many of . In addition to burrowing, other spontaneous behaviors can be assessed, including nesting construction and food hoarding (Deacon, 2006a; Rock et al., 2014). Blocking caspase activity prevents transsynaptic neuronal apoptosis and the loss of inhibition in lamina II of the dorsal horn after peripheral nerve injury. The main advantage of electronic Von Frey compared to manual Von Frey is that an increasing force is applied by a single filament. The device automatically records the temperature that paw withdrawal occurred (in this case 50C). doi: 10.1016/0006-8993(86)91138-8, Jirkof, P., Cesarovic, N., Rettich, A., Nicholls, F., Seifert, B., and Arras, M. (2010). Any long-term research involves mice and rats because of this unique aspect to the research. Pain 87, 149158. An experimental model for peripheral neuropathy produced by segmental spinal nerve ligation in the rat. For example, in C57BL/6 mice, the 50% withdrawal threshold determined using manual Von Frey is ~0.61 g, while using electronic Von Frey, the paw withdrawal thresholds are generally higher, with values of ~4 g obtained using MouseMet and ~6 g using Dynamic Plantar Aesthesiometer (Petrus et al., 2007; Minett et al., 2014; Deuis and Vetter, 2016; Gritsch et al., 2016). The criterion that constitutes a positive response to a filament varies between laboratories, with 20%40% withdrawal response rates over 510 applications being used typically (Scholz et al., 2005; Minett et al., 2011). While such behavioral changes may correlate to thermal allodynia or hyperalgesia, the contribution of additional sensations or complex behaviors to the preferred environmental temperature cannot be ruled out. . 14:14. doi: 10.1186/1471-2474-14-14, Pertovaara, A., Kauppila, T., and Hmlinen, M. M. (1996). Therefore, the results of the survey will be skewed to reflect the opinions of those who visit the website. To conduct a survey properly, you need to determine your sample group. (2007). Technology Addiction. (B) Hot plate test. Mol. Particular mention should also go to timely publication of data, be it positive or negative results, in order to reduce experimental duplication and unnecessary use of animals. The purpose of pain in the above cases is to alert an individual to withdraw from immediate tissue damaging stimuli and to prevent further damage to the site of injury during the healing process. LabSand is a natural, contaminant free, hydrophobic sterile sand that is spread in a. Burrowing in rodents: a sensitive method for detecting behavioral dysfunction. (2007). Lett. Unfortunately, many introductory . While the underlying principle of the temperature gradient assay is similar to the two-temperature choice assay, the animal is free to explore along the gradient (usually between 4C and 65C over a length of 120 cm) until they settle within their preferred temperature or comfort zone. The distinction between nociception and pain thus underlines a key difference in terminology when referring to communicating and non-communicating subjects. This includes minimizing the duration of models, replacing nocifensive model compounds for ones that cause shorter lasting nociception, or reducing the administered doses of compounds. Lab Animal Urine Collection: Traditional Methods And LabSand Rotation of the handle of the hand-held device initiates heating from room temperature to 60C at a rate of 2.5C/s, which is terminated automatically by paw withdrawal, removal of the probe from the paw by the operator, or on reaching a predetermined cut-out (usually 60C; Figure 3D). Exp. 10 Major Disadvantages of Technology [2022 Technology Disadvantages J. Adams, B. L., Guo, W., Gors, R. T., and Knopp, K. L. (2016). Well-established strains of rat are used to study a number of human diseases such as: obesity and diabetes cancer cardiovascular disease (including high blood pressure and heart failure). Animal models of pain: progress and challenges. Models and mechanisms of hyperalgesia and allodynia. Methods 224, 4857. Transcriptomic and behavioural characterisation of a mouse model of burn pain identify the cholecystokinin 2 receptor as an analgesic target. doi: 10.1016/j.joca.2016.05.022, PubMed Abstract | CrossRef Full Text | Google Scholar, Allchorne, A. J., Broom, D. C., and Woolf, C. J. In the Mouse Grimace Scale (Figure 6A), five facial features are scored: orbital tightening, nose bulge, cheek bulge, ear position, and whisker position (Langford et al., 2010). (2014). (2016). Evaluation of the usefulness of two established pain assessment tools in a burn population. Frontiers | Methods Used to Evaluate Pain Behaviors in Rodents In the conventional hot plate test, an unrestrained mouse or rat is placed on a metal surface maintained at a constant temperature, usually between 50C and 55C, and the response latency, which is the time taken to observe a nocifensive behavior, is recorded by the investigator (Figure 3B). TRPM3 is a nociceptor channel involved in the detection of noxious heat. This research has almost exclusively used a single procedure to induce the condition in animal models. Thoughts on limitations of animal models - ScienceDirect doi: 10.1016/S1474-4422(10)70143-5, Bautista, D. M., Siemens, J., Glazer, J. M., Tsuruda, P. R., Basbaum, A. I., Stucky, C. L., et al.

Pro Unlimited Wand Customer Service, Cooperative Coaching Style Examples, Articles OTHER

13840110d2d515487e83b87 disadvantages of using rats in research