02290nas a2200157 4500008004100000022002500041245021000066210006900276260001600345300002000361520163000381100002802011700002202039700002302061856004802084 2022 eng d a0023-6772, 1758-111700aThe use of ball pits and playpens in laboratory Lister Hooded male rats induces ultrasonic vocalisations indicating a more positive affective state and can reduce the welfare impacts of aversive procedures0 ause of ball pits and playpens in laboratory Lister Hooded male r cJan-13-2022 a0023677221106593 a

The advancement and quality of science rely on research that is robust and unbiased in its experimental design, execution, analysis, and reproducibility. In preclinical research, a better understanding of animal emotions and refinement of their husbandry, housing, and handling are important goals in providing good animal welfare in a laboratory setting which underpins rigorous research quality. Induction of positive emotional state in animals is a key component of their well-being, and one approach is to increase their environmental complexity using, for example, ball pits or playpens in rats. In this study, we recorded 50 kHz ultrasonic vocalisations (USVs) during animals’ exposure to the ball pit and playpen. We have previously shown that 50 kHz USVs provide a graded and quantifiable measure of an animal’s emotional state, and here find that access to the ball pit and playpen increases 50 kHz USVs, indicative of a more positive affective state. Using our affective bias test (ABT) we next quantified the animals’ emotional response to an aversive intervention and whether this could be attenuated by access to a playpen. The playpen exposure completely mitigated the negative affective state induced by an anxiogenic drug when compared with animals who experienced the drug in the home cage. Together, these findings suggest ball pits and playpens provide a simple and effective method to improve the welfare of laboratory rats and reduce the cumulative suffering they experience from their housing conditions and minor, aversive procedures.

1 aHinchcliffe, Justyna, K1 aJackson, Megan, G1 aRobinson, Emma, SJ uhttp://dx.doi.org/10.1177/0023677221106592002100nas a2200193 4500008004100000245012800041210006900169520141600238100002501654700001801679700002301697700002001720700002301740700002601763700002301789700001801812700002201830856005401852 2019 eng d00aEarly Life Maternal Separation and Maternal Behaviour Modulate Acoustic Characteristics of Rat Pup Ultrasonic Vocalizations0 aEarly Life Maternal Separation and Maternal Behaviour Modulate A3 a

Early separation of preterm infants from their mothers has adverse, long-term neurodevelopmental consequences. We investigated the effects of daily maternal separation (MS) of rat pups from postnatal days 2–10 (PND2–10) on neurobehavioural responses to brief isolation at PND12 compared with pups receiving controlled handling without MS. Ultrasonic vocalizations (USV) were measured at PND12 during two, 3-minute isolations occurring immediately before and after a 3-minute maternal reunion. There were no significant differences in acoustic characteristics between MS and control animals in the first isolation. However, in the second isolation, MS pups produced a greater proportion of high (~60 kHz) vs low (~40 kHz) frequency calls. During this isolation, control pups made longer and louder low frequency calls compared to the first isolation, whereas MS pups did the opposite. Maternal behaviour of control and MS mothers modulated pup acoustic characteristics in opposite directions; higher maternal care was associated with more low frequency calls in control pups but more high frequency calls in MS pups. We hypothesize that MS results in USV emission patterns reflective of a greater stress response to isolation. This translational model can be used to identify mechanisms and interventions that may be exploited to overcome the negative, long-term effects of MS.

1 aKaidbey, Jasmine, H.1 aRanger, Manon1 aMyers, Michael, M.1 aAnwar, Muhammad1 aLudwig, Robert, J.1 aSchulz, Alexandra, M.1 aBarone, Joseph, L.1 aKolacz, Jacek1 aWelch, Martha, G. uhttp://www.nature.com/articles/s41598-019-54800-z02938nas a2200229 4500008004100000245013700041210006900178520212800247653001802375653001802393653001402411653001302425653001602438653003502454653001502489653002402504653003602528653002702564100002302591700002702614856006702641 2019 eng d00aDissimilar interaction between dopaminergic and cholinergic systems in the initiation of emission of 50-kHz and 22-kHz vocalizations0 aDissimilar interaction between dopaminergic and cholinergic syst3 a

Rats emit 22-kHz or 50-kHz ultrasonic vocalizations (USVs) to signal their emotional state to other conspecifics. The 22-kHz USVs signal a negative emotional state while 50-kHz USVs reflect a positive affective state. The initiation of 22-kHz USVs is dependent on the activity of cholinergic neurons within the laterodorsal tegmental nucleus that release acetylcholine along the medial cholinoceptive vocalization strip. Emission of 50-kHz USVs is dependent upon the activation of dopaminergic neurons located within the ventral tegmental area that release dopamine into the medial shell of the nucleus accumbens. There have been reports that showed an antagonistic interaction between acetylcholine and dopamine during the expression of emotional states, and dopamine agonists decreased carbachol-induced emission of 22-kHz USVs. The current study tests the hypothesis that initial antagonism of dopamine receptors by systemic haloperidol or intraacumbens raclopride should increase the subsequent emission of 22 kHz USVs induced by carbachol from the lateral septum. Our findings showed that antagonism of dopaminergic signaling either via systemic haloperidol or via intracerebral raclopride did not alter the number of emitted 22-kHz USVs. Thus, inhibition of the mesolimbic dopamine system did not increase the magnitude of a negative emotional state. It was found, however, that prolonged emission of 22-kHz USVs initiated by carbachol caused a delayed rebound emission (R) of 50-kHz USVs appearing after 300 s of emission of 22-kHz USVs, i.e., when the response was subsiding. The R-50-kHz USVs were predominantly frequency modulated (FM) USVs and their number was directly proportional to the number of recorded 22-kHz USVs. The emission of R-50-kHz USVs was reversed by systemic pretreatment with haloperidol or intraacumbens injection of raclopride. It is argued that the R-50-kHz USVs represent a rebound emotional state that is opposite in valence and arousal induced by carbachol. Importantly, prolonged emission of amphetamine-induced 50 kHz USVs failed to show any vocalization rebound effect.

10aAcetylcholine10aAntipsychotic10aCarbachol10aDopamine10aHaloperidol10aLaterodorsal tegmental nucleus10aRaclopride10aRebound 50-kHz USVs10aUltrasonic vocalizations (USVs)10aVentral tegmental area1 aSilkstone, Michael1 aBrudzynski, Stefan, M. uhttps://linkinghub.elsevier.com/retrieve/pii/S009130571930259X02339nas a2200181 4500008004100000245016000041210006900201520166700270653001901937653001801956653002401974653002501998653002902023653001202052100002502064700002702089856004102116 2020 eng d00aAssociation of medial corticostriatal regions with amphetamine-induced emission of 50 kHz vocalizations as studied by Zif-268 expression in the rat brain0 aAssociation of medial corticostriatal regions with amphetaminein3 a

Behavioural sensitization of locomotion and 50 kHz ultrasonic vocalizations (USVs) following repeated amphetamine (AMPH) injections in rats has been extensively demonstrated. These two behaviours appear dissociable in their sensitization patterns and are thought to be reflective of underlying emotional states of the organism. Although AMPH is often used to induce 50 kHz USVs there is little research to date on the extent of cortical and subcortical forebrain region involvement in 50 kHz call production associated with the drug. Nor has general ergometric activity (a measure that in addition to locomotor activity includes all major muscular activity of the body) been investigated in such a framework. The present study sought to address this by performing a minimal sensitization protocol, utilizing only two injections, to investigate expression of the inducible transcription factor Zif-268 (Zif) among brain regions thought to be associated with 50 kHz USV emission. It was found that animals that spent a longer time emitting 50 kHz calls after a second AMPH injection showed statistically significant correlative patterns of Zif expression in medial prefrontal and striatal regions. These associations were not significant in animals that spent a shorter period of time calling after AMPH. There was also no significant correlation between any ergometric activity and time spent calling. The results provide evidence that the medial prefrontal cortices (prelimbic and infralimbic regions) of the rat may be involved with 50 kHz USV emission induced by AMPH in association with medial portions of the ventral and dorsal striatum.

10a50 kHz calls10aD-amphetamine10aErgometric activity10aImmediate early gene10aUltrasonic vocalizations10aZif-2681 aMulvihill, Kevin, G.1 aBrudzynski, Stefan, M. uhttps://bio.acousti.ca/de/node/5758702153nas a2200205 4500008004100000245014200041210007300183520141100256653001601667653002201683653003001705653003001735653001101765653001301776653002801789100002101817700002201838700002501860856006201885 2019 eng d00aPerinatal high‐fat diet impairs pup retrieval and induces sex‐specific changes in ultrasonic vocalization characteristics of rat pups0 aPerinatal high‐fat diet impairs pup retrieval and induces sex‐sp3 a

Rodent pups emit ultrasonic vocalizations (USVs) to solicit maternal behavior, promoting their survival. Conversely, maternal behaviors affect the expression of pup USVs. We previously demonstrated that a maternal diet high in saturated fat (HFD) alters maternal behavior and is associated with early maturation of pups and their stress physiology. Here, we assessed the developmental profiles of pup USVs using quantitative and qualitative measures on postnatal days (PND)7 and 13. Quantitative measures included call counts, duration, and frequency, while qualitative measures examined calls' sonographic structures. HFD offspring lacked the typical decrease in USV numbers with age observed among control offspring. They also had shorter calls at PND7 compared to control and HFD offspring at PND13. HFD female offspring showed a greater number of one‐frequency‐sweep calls, while male pups showed a greater number of two‐frequency‐sweep calls compared to control offspring. Concomitantly, HFD dams showed impaired pup retrieval on PND7. The data suggest that fewer USVs of shorter duration in HFD offspring may alter dam solicitation and thus impair maternal pup retrieval. This study highlights the impacts of perinatal HFD exposure on the dyadic reciprocal interaction between dam and pups, which may set the stage for long‐lasting effects on offspring physiology and behavior.

10adevelopment10amaternal behavior10amother–pup interactions10aperinatal high‐fat diet10arodent10asonogram10aultrasonic vocalization1 aAbuaish, Sameera1 aTse, Emmanuel, K.1 aMcGowan, Patrick, O. uhttps://onlinelibrary.wiley.com/doi/abs/10.1002/dev.2192302385nas a2200193 4500008004100000245013100041210006900172260001600241300001300257490000700270520172700277100002502004700002302029700001602052700002202068700002202090700002702112856005202139 2019 eng d00aSex differences in auditory brainstem response audiograms from vasopressin-deficient Brattleboro and wild-type Long-Evans rats0 aSex differences in auditory brainstem response audiograms from v cJun-08-2021 ae02220960 v143 a

Rats are highly social creatures that produce ultrasonic vocalizations (USVs) during social interactions. Brattleboro rats, a Long-Evans derived rat that lacks vasopressin (AVP) due to a mutation in the Avp gene, exhibit atypical social behavior, including fewer USVs with altered spectrotemporal characteristics during social interactions. It is unclear why Brattleboro rats produce atypical USVs, but one factor could be differences in auditory acuity between them and wild-type Long Evans rats with functional vasopressin. Previous studies have suggested a link between increased levels of AVP and auditory processing. Additionally, few studies have investigated sex differences in auditory perception by Long-Evans rats. Sex differences in auditory acuity have been found throughout the animal kingdom, but have not yet been demonstrated in rat audiograms. This study aimed to measure auditory brainstem response (ABR) derived audiograms for frequencies ranging from 1 to 64 kHz in male and female homozygous Brattleboro (Hom), heterozygous Brattleboro (Het), and wild-type (WT) Long-Evans rats to better understand the role of AVP and sex differences in auditory processing by these rats. We failed to detect significant differences between the ABR audiograms of Hom, Het, and WT Long-Evans rats, suggesting that varying levels of AVP do not affect auditory processing. Interestingly, males and females of all genotypes did differ in their ABR thresholds, with males exhibiting higher thresholds than females. The sex differences in auditory acuity were significant at the lowest and highest frequencies, possibly affecting the perception of USVs. These are the first known sex differences in rat audiograms.

1 aCharlton, Payton, E.1 aSchatz, Kelcie, C.1 aBurke, Kali1 aPaul, Matthew, J.1 aDent, Micheal, L.1 aDelano, Paul, Hinckley uhttp://dx.plos.org/10.1371/journal.pone.022209602468nas a2200205 4500008004100000022001400041245015500055210006900210260001600279520155900295653001601854653002001870653001401890653001901904653002901923100002601952700002301978700002302001856023802024 2019 eng d a0012-163000aSocial experience during adolescence in female rats increases 50 kHz ultrasonic vocalizations in adulthood, without affecting anxiety‐like behavior0 aSocial experience during adolescence in female rats increases 50 cJul-08-20203 a

Adolescents are highly motivated to engage in social interactions, and researchers have hypothesized that positive social relationships during adolescence can have long term, beneficial effects on stress reactivity and mental well‐being. Studies of laboratory rodents provide the opportunity to investigate the relationship between early social experiences and later behavioral and physiological responses to stressors. In this study, female Lister‐hooded rats (N = 12 per group) were either (a) provided with short, daily encounters (10 min/day) with a novel partner during mid‐adolescence (postnatal day 34–45; “social experience,” SE, subjects) or (b) underwent the same protocol with a familiar cagemate during mid‐adolescence (“control experience,” CE, subjects), or (c) were left undisturbed in the home cage (non‐handled “control,” C, subjects). When tested in adulthood, the groups did not differ in behavioral responses to novel environments (elevated plus maze, open field, and light‐dark box) or in behavioral and physiological (urinary corticosterone) responses to novel social partners. However, SE females emitted significantly more 50 kHz ultrasonic vocalizations than control subjects both before and after social separation from a familiar social partner, which is consistent with previous findings in male rats. Thus, enhanced adolescent social experience appears to have long‐term effects on vocal communication and could potentially modulate adult social relationships.

10aadolescence10aglucocorticoids10aneophobia10asocial novelty10aUltrasonic vocalizations1 aEmmerson, Michael, G.1 aSpencer, Karen, A.1 aBrown, Gillian, R. uhttps://onlinelibrary.wiley.com/doi/abs/10.1002/dev.21906https://onlinelibrary.wiley.com/doi/pdf/10.1002/dev.21906https://onlinelibrary.wiley.com/doi/pdf/10.1002/dev.21906https://onlinelibrary.wiley.com/doi/full-xml/10.1002/dev.2190602148nas a2200169 4500008004100000022001300041245011600054210006900170260001600239520154000255100002901795700002501824700003101849700002401880700003301904856004101937 2019 eng d a0924977X00aCharacterization of rat ultrasonic vocalization in the orofacial formalin test: Influence of the social context0 aCharacterization of rat ultrasonic vocalization in the orofacial cJan-08-20193 a

Rats emit ultrasonic vocalizations (USVs) about 22 kHz and 50 kHz sound frequency to communicate the presence of negative or positive emotional states, respectively. The calling behavior may be influenced by several factors, including environmental factors. Likewise, pain behavior can be modulated according to the social context, and also can be transferred to conspecifics through direct observation and/or social interaction. Herein we investigated if acute pain induction was related to changes in emission of aversive and appetitive calls and how different social contexts affected the nociceptive behavior and USVs. Our results demonstrated that orofacial formalin injection in rats induced aversive calls in addition to the nociceptive behavior, and both are reduced by systemic treatment with morphine (2.5 mg/kg). Exposure of formalin-injected rats to cagemates had no effect on the nociceptive behavior or calls emitted by the demonstrator, but the observer showed emotional contagion of pain. In contrast, exposure of formalin-injected rats to non-cagemates decreased the nociceptive behavior of the demonstrator, without affecting the calls emission. The emotional contagion was not detected in non-cagemates or in cagemates separated by a visual barrier. In conclusion, we suggest that familiarity and the visual contact contributes to emotional contagion of pain. USV analysis may represent an additional measure in the evaluation of the emotional aspect of orofacial pain, and for the study of pain modulation.

1 aBarroso, Amanda, Ribeiro1 aAraya, Erika, Ivanna1 ade Souza, Camila, Pasquini1 aAndreatini, Roberto1 aChichorro, Juliana, Geremias uhttps://bio.acousti.ca/de/node/5733401936nas a2200265 4500008004100000022001400041245006600055210006600121260001600187520115100203653001701354653001801371653002001389653001601409653003001425653000901455653001201464653001701476653002001493653002201513653002001535653002901555100003101584856005501615 2018 eng d a1548-358400aVocal Signals of Sexual Motivation in Male and Female Rodents0 aVocal Signals of Sexual Motivation in Male and Female Rodents cJan-10-20203 a

Purpose of the Review

Rodents produce ultrasonic vocalizations (USV) under different social contexts, including courtship and reproduction. The present review aims to summarize the behavioral, bioacoustical, and physiological evidence that USV are reliable signals of sexual motivation in both male and female rodents.

Recent Findings

USV are actively produced by both sexes during sexual interactions, contrary to earlier assumptions. Male-typical and female-typical vocal behaviors can be identified. Calling rates and acoustic parameters, such as call duration, frequency, and energy, can be modulated rapidly over time by motivational state and sexual context. USV produced in response to sexual context could be regulated by the brain on a moment-to-moment basis through non-classical mechanisms of steroid action. Finally, I provide some practical considerations for the acoustic and statistical analyses of these vocal signals.

Summary

USV can be used as signals of sexual motivation in both sexes to study brain and hormonal mechanisms underlying sexual behavior or sexual differentiation.

10abioacoustics10acommunication10aGolden hamsters10aHouse mouse10aNongenomic steroid action10aRats10aRodents10aSex steroids10aSexual behavior10aSexual motivation10aSyrian hamsters10aUltrasonic vocalizations1 aFernández-Vargas, Marcela uhttp://link.springer.com/10.1007/s11930-018-0179-9