Well, hello everyone, welcome to today's live broadcast.  Normal behavior of rodents - understand it, then respect it. I am Marcel Parent, and I will be your moderator for today's event. We have a few important announcements to make before we begin. This webcast is designed to be

interactive, so we encourage you to ask questions during the event. You can submit questions by typing them in the Q&A box, which can be found by clicking on the green Q&A button at the lower left of the presentation window. We'll try to answer as many

questions as we can. You can enlarge the slide window by clicking on the screen icon in the lower right-hand corner of the slide window. If you have any technical problems viewing or hearing this presentation, please click on the support button at the top right of your presentation window or submit your problem through the green Q&A button on the lower left. I would now like to introduce today's speaker, Dr. Marina Snipkovski. Dr. Marina Snipkovski has a DVM, a Masters of Science and a PhD. Her academic background encompasses a Doctorate in Veterinary Medicine, which she graduated with honors from the Veterinary School of the Wos Iris University in 2004. Her fields of expertise are in clinical ethology, animal behavior and neurosciences, laboratory animal science, biostatistics and experimental

design. She's a Diplomate in Canine and Feline Internal Medicine ER from the Las Americas University in 2009. She's also a Diplomate in Clinical Ethology from the Latin American Veterinary Ethology College in 2012. She has a specialization in

She has a Masters in psychoneuroimmunoendocrinology from the Fabro University, which she obtained in 2012. She's a master

student in laboratory animal science and welfare at the Barcelona University in Spain. She was there from 2015 to 2018, and she has a PhD in neurosciences from the veterinary school at Buenos Aires University in 2013. As you can see, Marina is

very well qualified for this presentation. In her current position, she's at the IBCN laboratory as the animal facility manager, and in coordination and supervision of the animal health and welfare at the Medicine School in Buenos Aires. She has been in that position since March 2012. Her professional memberships include

the career for research support of the National Research Council, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), at the Institute of Cell and Molecular Biology, Medicine School, Buenos Aires University. She is an IO member at the Veterinary School Research Institute at the Del Salvador University. She has been a member of the IO since

2013. She is a board member of the Argentinian Association of Laboratory Animal Science and Technology, and she's a pro-secretary since March 2014. She is a head professor of biostatistics at the Veterinary School at the Salvador University since August

2008. I will now turn it over to Marina Snipkowski for her presentation. So, Marina, well thank you, Marcel, for that very kind introduction. Um, good morning to everyone. I would like to thank you for being there for choosing this lecture and to

Thank the organizers of this event for inviting me, and also I would like to apologize for my poor use of English since, as you know, I'm from Argentina, so this is not my mother tongue. But I'll just do my best, and I think we'll manage so.

Let's talk about behavior. We can define behavior as an individual response, an animal response to a stimulus, whether the stimulus is internal, for instance, um, a change in a hormone level, or an external stimulus such as a change, a variation in the environment. So the main function of

behavior is to allow the animal to adapt to those variations in the environment, and also for our benefit, behavioral response is something we can see or we can even measure, so that response will be reporting us about an internal processing, something very complex that

is happening inside the animal, and as we cannot see it or touch it or measure it, we can infer about it with the something we can see, that is the behavioral response. So this in terms of processing could be a physiological state, for instance, estus in females, whether um, we

can also infer about pathological states such as sickness behavior or even emotional states, for instance, fear. We can infer that an animal is fearful uh with its behavior. Also, we can know what motivational state the animal is in uh by seeing its behavior, for instance, uh

hunger or sexual arousal. Also, this behavioral response can allow us to assess the wellbeing of that animal, always with objective measurements of these behaviors, and um, we can assess also the adaptation capabilities of that animal, observing uh its behavior and its

behavioral response to change in the environment but I really wonder if we know the normal behavior patterns of the animals we work with of the animal species we are used to working with in order to know their normal behavioral patterns we should know first the natural history of that species that is

um which are its ancestors its wild lore and what evolution and domestication made uh and and provoke changes not only in their features their external and phenotypic features but also in their behavior that is a process we can call in our world in um a process

of laboratory that would be domestication of laboratory animals so we should know the behavior phylogeny and ontogeny and of course which captivity variations were um across the time of evolution so if we know uh sorry if we know how the normal behavior is we are

capable of assessing if there's an altered behavior which could be due to a physical illness or even to emotional distress such as um transportation um any kind of experimental procedure or even a social conflict so if we know how the normal behavior is

and we can recognize altered behavior we will be able to respect and to ensure animal welfare knowing that one of the freedoms that we usually try to respect by ensuring animal welfare is the freedom to express normal behavior of course in order to respect it we

first need to know it so actually the behavior repertoire of uh rats is very complex I'll just choose in this talk to speak about some of the patterns that I think are most important for the fact the animal facility manager of course all of the

Patterns are important, but we are going to discuss social, uh, agonistic, territorial, exploratory, sexual, and maternal behaviors today. But first, we should uh, review what are, or how are sensory systems involved because of course, they are very related to the expression of normal

behaviors. So smell, of affection, is obviously the best developed sense and is required for um, food finding, for territory recognition, for uh, predators and and social skills. But also the the sense of smell provides a very important exchange of information system, whether it's um, the creation, urine, feces and

even uh, scent gland secretions. There are a few compounds that are very important for this communication via uh, smell sense that are, for instance, major urinary proteins and pheromones. We are going to talk a lot about pheromones today. What about sight? Actually, sight is

the least important sense in rodents. As you may know, their vision is dichromatic, that is, they are blind to to red color, but they can see ultraviolet. Also, they have a very poor, poor visual acuity, especially in albino strains, it is worse, is even worse, but

they can see a high contrast. You know about hearing well, you may know that they have a broader spectrum compared to humans, and they uh, can vocalize in an ultrasonic sound. So of course, we are deaf to that and to in it, in order to

hear it or or to measure it, we need a special apparatus. Um, this ultrasonic signaling is used for uh, mother pup calling, for sexual calling, and also um, for warning about predators or cage intruders. And about touch, they have a very specialized hair, uh, tactile hair

that are called VRAs, um, that is uh connected with a very specialized region in the brain called in order to integrate that information. But what happens with their sensory systems in captivity in our animal facility conditions? Actually, we usually use a very bright light which is not the best

for their sense of sight. It would be better to use a red light when it's possible, or a yellow light, or a mercury light that is less bright. Same thing or similar happens with environmental sounds. Actually, sometimes there are they are exposed to electronic devices and other equipment

sounds that maybe they have they emit an ultrasonic sound. Of course, we don't know because we we cannot hear it. What about smell? Uh, in our daily daily basis of bed CH uh bedding change, we remove the odors and it makes disappear the their

scent marking disappear. So it might it doesn't always but it might uh create some sort of social problems between cagemates. So a good idea would be to renew only uh, let's say, a 90% of of the bedding and leave 10% remaining of the

bedding that has the those special scents scent and and odors that are very important for them to mark their territory and their social relationships. And about social behavior, actually social behavior should we should say that it's the most important behavior we should study in world and in

every animal. Uh, there are different social aggregation patterns. A species could be strictly gregarious, it could be solitary, or it could be sociable or S social or facultative precarious. It depends on the resources and of course it depends on the species. It's very specific of the

species so uh in order to have um a social behavior they need to communicate with each other as as we said communication can be visual uh through gestures and body postures tactile through touching each other or or passing against each other or hling and

of course it's very important the AL active and semiochemical communication that is the fonal communication and the vocalizations that that as we said they could be audible or ultrasonic there are different social behavior patterns for instance social attention that is to detect and to uh go

towards uh con specific social investigation smelling and vocalizing and agonistic behavior that we'll discuss further on uh of course for the social behavior to exist it has to be organized so um species has its own social organization and hierarchy and we will

discuss it as well so the species that are strictly gregarious for instance wats guinea pigs and jills uh they need and they must aggregate they have an inner drive to aggregate to live together of course this um social life um provides protections provides

easiness to find food so there's a hierarchy there's a social organization that is usually called a colony and it's a hierarchical organization the hierarchy uh starts with the dominant male that is usually the biggest and the heaviest one um he dominates over food over

space control and of course over reproduction usually in a colony only the dominant male is able to reproduce to mate and of course this um dominance it's um is shown with dominance postures with fighting with barbering that is more typical in in mice

so continuing with the hierarchy comes the reproductive female group that they have their own hierarchy among females and they usually um raise up the the pups together we will talk about it later with maternal behavior then the subordinate males and then the young and the juvenile but what about m actually M

should be considered as facultative gregarious species because they can live together and they would they they would aggregate or not depending on resources and of course depending on their own conspecific attraction that is the internal factor that makes them to live together actually the my social Al there

is yet poorly understood it is supposed to be a despot mouse then a prominent mice group and then the subordinate M and the only species we usually work with that is solitary uh species is the hamster as you may know so what happens in captivity and

social behavior actually uh we need to know how the social pattern is in order to respect it uh the gregarious species should be house grouped for and actually this social housing is supposed to be the best source of enrichment um given the um proper amount

of space in the and the proper cage dimension and of course the number of animals and if they have enough resources because if not it could um generate competition and fighting so there are some um experimental proceedings that that need let's say social is is isolation sorry um when

it's for short periods like surgery or some experimental procedures well it can be let's say tolerated but then it when it is for longer periods it is actually the main source of emotional and social distress in the various species so so we should be aware of

This and there are a lot of behavioral tasks that um are developed uh over these social interactions, for instance, social defeats in which we should take into account that it is stressful both for the intruder and for the resident. This is usually used with males, they can be both stressed

out about this uh social interaction and we also should be very aware that there can be some social communication behind us because they can communicate through ultrasound vocalization and pheromone signaling that we are, we are um deaf about it and we cannot see uh what's going on and they can warn

each other about something that is going on because they have um alarm vocalization and even alarm pheromones. What happens with agonistic behavior that of course is very related to social behavior and it's needed to um to make the social structure um, you remain, let's say so the aggression

or the threatening postures that has to do with dominance and with submission or uh usually there's some posture of offensive aggression or dominance um as a threatening posture that involves piloerection, kyphosis, sometimes persecution and an approach uh sometimes allogrooming and as

you can see here in the picture in in eyes is very common, the barbering uh that is the chewing of the the fur of the subordinate in this case and there can be fighting, biting, boxing, and and wallowing in a fight, especially between males and the defensive or submission

posture uh that is actually intended to have an, let's say, an appeasement function um it's usually a lateral position or a spine position uh exposing the ventral abdomen as you can see in the about picture uh with two rats uh fighting um when one of them it's

acquiring the dominance position and the other the subordinate position so there are very typical sequences first starting with an let's say ambivalent posture trying to maintain distance and even if the the animals I mean if the animal is uh subordinate he can even breathe uh to

avoid and to appease um the dominant behavior or aggressive behavior uh if possible the subordinate will try to escape and if not um the dominant will try to attack or the subordinate will try to defend itself so what happens with the agonistic behavior in captivity as I said before we should

respect the aggregation pattern of the species um that if if the species is gregarious they should be group housed while if it's for instance that they are facultative bearers we should um see if we should group house them or not regarding uh depending on resources

habituation to cagemates number of animals the cage size Etc and about regrouping well actually we should never regroup um adult especially if they are male um if they were not raised up together because they they will fight of course also we need to recognize those

postures of do and submission and in the case of mice especially we should recognize this so-called barbering effect that is the over grooming and the over barbering that can even cause an ulcerative dermatitis when it's excessive of

course okay about territorial territorial behavior actually the communal or the group territory makes protection finding food and storing large amounts of food a lot easier of course it depends on the animal density and on resources and the main functions of uh territorial behavior are social

functions reproductive of course for instance nesting behavior residential but I think it's I have a misspell here sorry um when there are low activity periods the animals  um hang out there in in their territory and of course they can use it to um defend

themselves from predators for food storage as I saw as I said before and this uh territory is very well defended uh usually by the dominant male of the colony with a territorial aggression to intruders whether the they are conspecifics or predators um well I I said this before mice are very territorial against intruders and this is even uh used in a behavioral dark um so the territorial behavior of the wild ancestors of our laboratory animals is to dig or to burrow um

underground galleries and tunnels with and caves with several several entrances usually these entrances are uh next to some stones or bushes or uh a bunch of leaves leaves uh in order to recognize uh these ter and the entrance to go back as if it were a benchmark for them to

recognize uh they of course they also use olfactory cues to mark their territory with urine I'm sorry and uh fecal marking and also with sPLS marking through pheromones um mice have this um very specialized and developed sense of

recognition and spatial orientation they use the environment environmental cues and special keys and benchmarks to recognize their territory and as they can form a cognitive map about their own territory this is very used um for behavioral tasks um that are assessing spatial learning such as mazes all kind

of kind of mice um are based on these behaviors Uh what happens in captivity and territorial behavior actually due to a small cage size usually um the territorial behavior and the kinetic behavior it's very little expressed because they don't have enough space

to express it um nevertheless we can increase this uh space or the way of expression of territorial behavior by uh environmental enrichment uh for instance using tunnels or stairs or ramps as you can see in the picture and if they need more exercise because in the wild their ancestors

would um walk long distances to in order to find food um which doesn't happen in captivity so we could uh engage their environment and try to make um them make more exercise by using a running wheel or uh different levels in their cages also we can use loose material so

that they can dig and burrow and uh to express the nesting behavior that is very important in rodents especially in mice and exploratory behavior that is uh very related of course to territorial behavior um it's very intense in rats uh and although this is a self-motivated

behavior that is it has um inner drive uh to explore their environment uh it always increases with novelty with a new uh stimulus so the exploration for the environment has main functions to get familiarized with this environment to find new escape routes from predators to

search for food and for mice as well and rats have this uh distinctive motor patterns to explore they can either walk run jump climb dig and even swim to explore their behavior their their I'm sorry their environment their surroundings and they usually do it in

This typical segment of uh fast progressions then attention and they stretch to smell a little bit further and they continue to march uh to where they were going and they use a wary posture as well to see what's farther away uh this exploratory behavior is

also uh used as um as a a normal pattern um to to make some behavioral tasks that based on this exploratory behavior um for instance all kind of maze so what happens in captivity with exploratory behavior actually our animals live in a very monotonous

environment that is they don't have any novelty or very little new stimuli to get involved in exploration so what can we do about it um well we can enrich their environment with some novelty and with with some complexity in the environment it of

course will induce exploration we can use several objects we can use well as you can see here in the picture um whether it's something you buy and it's quite expensive or it's something you normally throw away in the garbage such as cardboard tubes and

boxes so um any of these objects and this um environmental enrichment devices will um increase exploration and um and enrich their complexity in their environment but we should be aware that excess of novelty uh it's also stressful because it makes the the environment very um difficult to predict

very unpredictable and that is also stressful so we should balance the novelty uh so that is not stressful for the animals uh well sexual behavior uh sexual behavior is ruled mostly with um by pheromones as I said before pheromones are very important for communication

between Robin, um, it's what it's called, **SC** chemical communication because it's a chemical way of communication and it's involved in **CIP**, uh, there are sexual attraction pheromones and well, **tip** actually involves also ultrasonic calling for, for

mating, but also these pheromones are, um, involving a few, um, special, let's say, effects on behavior, sex behavior, and on endocrinal, uh, variations in the physiology of the animals. For instance, the **Vanderberg** effect that, um, when

there's a male, uh, present it can accelerate the puberty onset on a group of prepuberal female only due to pheromone, uh, sensing, and there's the **Lee-Boot** effect that, uh, when no male is present the group of female will have irregular, uh, estrous cycle or even no cycle at all. They

they will not be cycling and on the contrary, the **Whitten** effect, um, explains how the male urine, uh, with these major urine proteins I mentioned before will elicit estrous in cycling, uh, females, and this is very used for synchronizing estrous. This is very, very

commonly used in animal facilities to synchronize female estrous. Actually, um, we should be aware of this **Bruce** effect that is when a different male that was not the, the mate of the female, um, is present during the first third of the pregnancy, they can, uh,

be there can be, um, up to 50% embryo resorption, so we should be, uh, should take care of this as well. What happens in captivity with sexual behavior? Well, actually, uh, all of reproductive rate depends on management. Um, it all depends on us, on, on

the managers um the directed mating is actually against the natural preferences of animals um it does not respect their hierarchy nor preferences because there are preferences uh for mating and um even worse is inbreeding because it goes against the natural preference uh that

animals have for unrelated mates so compatibility complex I mean they try to mate with animals that are not related to them and in inbreeding we do exactly the opposite so we should be aware of that of course we use um some of the effects I told you before to synchronize

estrus we use it let's say in our benefit um and that can be made by using a little bit of bedding that is um that has some male urine and putting it in the female cage what about maternal Behavior well birth as you may know is

usually nocturnal so it's very difficult to see and of course take pictures of that's why this one is very difficult to see that that female mates is given both um and parenting is a very complex Behavior pattern it's actually cooperative it's communal uh among the various species

such as rats and it also can be um communal among mice um this all nursing um exists and it's it's very typical and we can even use it for a benefit if we have some orphan pups that means that female will nurse pups that are not of her

own but were born and given birth from another female also the parenting Behavior includes licking of the pups uh giving them physical protection uh uh recovering and transporting uh the pups to this scruffing behavior that you can see in the pictures and of course in order to nurse

um their their pups the female will adopt adopt um this um lactating posture um you know lying with um exposing her her belly in order that um the pups can nurse can can milk so what happens in captivity and with maternal behavior actually um all management

problems can affect pup survival rate oh so again it depends on us um and why is that because all sources of stress like for instance noise smell uh I don't know all those overpopulation they can lead uh to maternal behavioral disorders such as SP neglect or maternal

indifference there is lack of maternal care and and nursing and proper nursing so um actually it is it is very rare to see pups killing and cannibalism even though it is reported what usually happens it the is that pups can die

because of um bad mothering or or a lack of maternal care and then there's uh the normal scavenging behavior that is part of the uh feeding behavior the feeding pattern that is um absolutely normal in in Wens so actually um it's not that

common to see cannibalism but to see um a female feeding with the pup corpse but probably she didn't directly kill it um sorry sorry oops well um what I I I wanted to tell you that also excessive maternal care excessive licking uh can be

um uh bad for the pup I mean it can even um well maybe not kill them but it can um injure them by an excessive licking so probably signon bride will agree that excessive maternal care is also bad for the pups okay and now to sum up um as I've

said before we need to first know and understand what normal behavioral patterns are involved in in order to respect it and to ensure Animal Welfare it is very important then to understand the RO ethogram and to study it because it will help us to assess

welfare in animals as I said before as a sent variable that will tell us about internal processing very processing that is happening under me and about emotional states of those animals we are studying and if we want to ensure the freedom to express normal Behavior

patterns first we need to know them if not we will not be able to respect them and also if we know how normal behavior is in bent we will be able to select the proper animal model for um I don't know some task we need to do or

for an illness we want to model uh we will be able then to um decide which species to use which strain and um if there's a behavioral disorder in that animal as a model of a human behavioral disorder we need to be able to recognize normal from um abnormal

or from illness um or from a disorder also if we know how normal behavior is we will be able to um select uh the proper or the best behavioral task we should use for that model for instance for a neuros psych psychiatric disorder and um as I've said we need to uh know the

Marina Snitcofsky - Normal behavior of rodents Understand it, then respect it

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