Features Of Ultrasonic Vocalizations Research Articles

50-kHz ultrasonic vocalizations do not signal social anhedonia in transgenic DISC1 rats.

Patients diagnosed with neuropsychiatric disorders, such as autism and schizophrenia, suffer from disorganized speech. The disrupted-in-schizophrenia 1 (DISC1) protein pathway is considered a risk factor for the development of several psychiatric disorders and plays an important role in the dysregulation of dopamine (DA), which in turn plays an important role in the regulation of ultrasonic vocalizations (USVs) in rats. Moreover, the DISC1 protein pathway has been identified as a cause of social anhedonia, that is, a decrease in the drive for social interactions. USVs transmit specific affective information to other rats, with 50-kHz calls indicating a positive affective state in rats. Dysregulation of the dopaminergic system impacts the qualitative and quantitative features of USVs, such as duration, peak frequency, and the call rate. In this study, we thus used a well-established transgenic DISC1 (tgDISC1) rat line to investigate whether the neural (decreased DA levels in the dorsal striatum, amygdala, and hippocampus (HPC)) and behavioral (social anhedonia) features of tgDISC1 rats could be manifested through the modulation of their 50-kHz USVs. Analyses of three features (call rate, duration, and peak frequency) of all 50-kHz revealed no significant differences between groups, suggesting decreased DA levels in the dorsal striatum and amygdala, and HPC may affect social interaction but leave 50-kHz USV production intact.

Testosterone Increases the Emission of Ultrasonic Vocalizations With Different Acoustic Characteristics in Mice.

Testosterone masculinizes male sexual behavior through an organizational and activational effects. We previously reported that the emission of ultrasonic vocalizations (USVs) in male mice was dependent on the organizational effects of testosterone; females treated with testosterone in the perinatal and peripubertal periods, but not in adults, had increased USV emissions compared to males. Recently, it was revealed that male USVs have various acoustic characteristics and these variations were related to behavioral interactions with other mice. In this regard, the detailed acoustic characteristic changes induced by testosterone have not been fully elucidated. Here, we revealed that testosterone administered to female and male mice modulated the acoustic characteristics of USVs. There was no clear difference in acoustic characteristics between males and females. Call frequencies were higher in testosterone propionate (TP)-treated males and females compared to control males and females. When the calls were classified into nine types, there was also no distinctive difference between males and females, but TP increased the number of calls with a high frequency, and decreased the number of calls with a low frequency and short duration. The transition analysis by call type revealed that even though there was no statistically significant difference, TP-treated males and females had a similar pattern of transition to control males and females, respectively. Collectively, these results suggest that testosterone treatment can enhance the emission of USVs both in male and female, but the acoustic characteristics of TP-treated females were not the same as those of intact males.

High seizure load during sensitive periods of development leads to broad shifts in ultrasonic vocalization behavior in neonatal male and female C57BL/6J mice

There is increasing evidence that seizures during early development can impact ultrasonic vocalizations (USVs) emitted from neonatal mice. However, most of the effects of early-life seizures have been reported using chemoconvulsants that produce continuous seizures (status epilepticus). In the present study, we evaluated the impact of different seizure frequency loads during early-life vocalization development in C57BL/6J male and female mice. For the high seizure load (HSL) paradigm, we administered 3 flurothyl seizures to mice on postnatal day (PD) 7 through PD11, and recorded USVs on PD12. We found that the induction of seizures across PD7–11 resulted in increased average duration (P < 0.05) and cumulative duration (P < 0.05) of USVs across both sexes. Call-type analyses indicated several call-type changes, including reduced production of complex call-types from males' HSL condition. For the low seizure load (LSL) paradigm, we induced 3 flurothyl seizures only on PD10 and recorded USVs on PD12. We found no change in any spectral or temporal features of USVs. However, call-type production analyses indicated that both male and female animals from the LSL paradigm also produced changes in call-types. This study provides evidence that the magnitude of communication impairment following seizures is significantly impacted by seizure frequency load early in development.

Social isolation produces no effect on ultrasonic vocalization production in adult female CBA/CaJ mice.

Mice produce ultrasonic vocalizations (USVs) in a wide variety of social contexts, including courtship, investigation, and territorial defense. Despite the belief that mouse USVs are innate, social experience may be necessary for mice to learn the appropriate situation to emit USVs. Mouse USVs have been divided into categories based on their spectrotemporal parameters, but it is currently unclear if social experience changes these parameters (e.g., frequency and duration) or the proportion of calls from each category produced. Social isolation has been found to influence USV production in male mice. To investigate the influence of social isolation on vocal behavior in female mice, recordings were made of USVs emitted to unfamiliar male and female mice by subjects with one of three types of social experience. Twenty-four adult female CBA/CaJ mice either lived alone, lived with other females only, or lived with other females and had limited access to a male. Mice were recorded while in isolation, ensuring all recorded USVs were from the female of interest. Vocalizations were separated into nine categories and peak frequency, duration, and bandwidth were measured for every call. Socially isolated mice did not produce significantly more USVs or USV types than socially experienced mice. Social isolation did not have a significant effect on the features of USVs, suggesting production of USVs may not be learned in female mice.

Effects of the Endocrine-Disrupting Chemicals, Vinclozolin and Polychlorinated Biphenyls, on Physiological and Sociosexual Phenotypes in F2 Generation Sprague-Dawley Rats.

Background:Exposure to endocrine-disrupting chemicals (EDCs) during gestation influences development of the F1 generation offspring and can result in disease and dysfunction in adulthood. Limited evidence suggests consequences on the F2 generation, exposed as germ cells within the F1 fetus. These F2s provide a unique window into the programming effects of EDCs.Objective:This study assessed intergenerational effects of EDC exposure on adult physiology and behavior in Sprague-Dawley rats.Methods:Pregnant rats were exposed to either a polychlorinated biphenyl (PCB) mixture, Aroclor 1,221 (A1221), the fungicide vinclozolin (VIN), or the vehicle (VEH) (6% dimethylsulfoxide in sesame oil) alone. A1221 is weakly estrogenic, while VIN is antiandrogenic, enabling us to compare different classes of EDCs. The F1 male and female offspring were bred to generate the paternal- and maternal-lineage F2 generation. This F2 generation was assessed for physiological outcomes, ultrasonic vocalizations (USVs), and sexual behavior in adulthood.Results:Each EDC caused phenotypic effects in a sex- and lineage-dependent manner. The most robustly affected group was the paternal-lineage males. F2 VIN paternal male descendants had increased body weight throughout the lifespan, lower concentrations of circulating estradiol, and lower adrenal and testicular indices. Both VIN and A1221 paternal-lineage males also exhibited the greatest number of changes in the characteristics of USVs in response to an opposite-sex animal and changes in sexual behaviors in a mating test.Conclusion:Exposure of rats to EDCs at the germ cell stage led to differences in the physiological and behavioral phenotype later in life, especially in males. This finding has implications for multigenerational physiological and reproductive health in wildlife and humans. https://doi.org/10.1289/EHP3550

Effects of prenatal ethanol exposure on acoustic characteristics of ultrasonic vocalizations in rat pups

Rat pups produce ultrasonic vocalizations (USVs) on isolation from their dam. Ultrasonic vocalization is a sensitive tool for evaluating social behavior between pups and their dam. Prenatal ethanol-exposure leads to a reduction in USVs and have the potential of inducing difficulties in social behavior between pups and their dam. However, effects of prenatal ethanol-exposure on the acoustic characteristics of USVs remain unclear. In this study, we recorded USVs produced by rat pups that were prenatally exposed to ethanol and examined their acoustic characteristics. Ethanol was administered to 13 pregnant rats in three stages by gradually increasing concentrations between gestational days (GDs) 8–20. From GDs 14–20, ethanol-containing tap water at concentrations of 30% and 15% (v/v) was administered to the high- and low-ethanol groups, respectively. Tap water without ethanol was given to the control group. On postnatal days (PNDs) 4, 8, 12, and 16, individual newly-born pups were isolated from their dam and littermates and USVs produced by them were recorded for 5 min. The number of USVs in the high-ethanol group was greater than that in both low-ethanol and control groups on PND 12. The mean, minimum, and maximum fundamental frequencies of USVs were elevated in the high-ethanol group compared with that in both low-ethanol and control groups. Higher amplitudes of USVs were produced by male pups in the high-ethanol group than in those in both low-ethanol and control groups on PND 12. These results suggest that prenatal ethanol exposure changed emotionality and accordingly, the high-ethanol group produced more USVs as distress calls.

Contextual Modulation of Vocal Behavior in Mouse: Newly Identified 12 kHz "Mid-Frequency" Vocalization Emitted during Restraint.

While several studies have investigated mouse ultrasonic vocalizations (USVs) emitted by isolated pups or by males in mating contexts, studies of behavioral contexts other than mating and vocalization categories other than USVs have been limited. By improving our understanding of the vocalizations emitted by mice across behavioral contexts, we will better understand the natural vocal behavior of mice and better interpret vocalizations from mouse models of disease. Hypothesizing that mouse vocal behavior would differ depending on behavioral context, we recorded vocalizations from male CBA/CaJ mice across three behavioral contexts including mating, isolation, and restraint. We found that brief restraint elevated blood corticosterone levels of mice, indicating increased stress relative to isolation. Further, after 3 days of brief restraint, mice displayed behavioral changes indicative of stress. These persisted for at least 2 days after restraint. Contextual differences in mouse vocal behavior were striking and robust across animals. Thus, while USVs were the most common vocalization type across contexts, the spectrotemporal features of USVs were context-dependent. Compared to the mating context, vocalizations during isolation and restraint displayed a broader frequency range, with a greater emphasis on frequencies below 50 kHz. These contexts also included more non-USV vocal categories and different vocal patterns. We identified a new Mid-Frequency Vocalization, a tonal vocalization with fundamental frequencies below 18 kHz, which was almost exclusively emitted by mice undergoing restraint stress. These differences combine to form vocal behavior that is grossly different among behavioral contexts and may reflect the level of anxiety in these contexts.

Determining Ultrasonic Vocalization Preferences in Mice using a Two-choice Playback Test.

Mice emit ultrasonic vocalizations (USVs) during a variety of conditions, such as pup isolation and adult social interactions. These USVs differ with age, sex, condition, and genetic background of the emitting animal. Although many studies have characterized these differences, whether receiver mice can discriminate among objectively different USVs and show preferences for particular sound traits remains to be elucidated. To determine whether mice can discriminate between different characteristics of USVs, a playback experiment was developed recently, in which preference responses of mice to two different USVs could be evaluated in the form of a place preference. First, USVs from mice were recorded. Then, the recorded USVs were edited, trimmed accordingly, and exported as stereophonic sound files. Next, the USV amplitudes generated by the two ultrasound emitters used in the experiment were adjusted to the same sound pressure level. Nanocrystalline silicon thermo-acoustic emitters were used to play the USVs back. Finally, to investigate the preference of subject mice to selected USVs, pairs of two differing USV signals were played back simultaneously in a two-choice test box. By repeatedly entering a defined zone near an ultrasound emitter and searching the wire mesh in front of the emitter, the mouse reveals its preference for one sound over another. This model allows comparing the attractiveness of the various features of mouse USVs, in various contexts.

Temporal and spectral differences in the ultrasonic vocalizations of fragile X knock out mice during postnatal development

The fmr1 knock out (KO) mouse has been a useful animal model to understand pathology and treatment of FXS, both anatomically and behaviorally. Ultrasonic vocalizations (USVs) are a behavioral tool to assess early life communication deficits in mice. Here, we report on the temporal and spectral features of USVs emitted after maternal separation in wild type (FVB/N) and fmr1 KO pups at postnatal days (P) P4, P7 and P10. The results show changes in the number and duration of calls in fmr1 KO pups and wild type pups were dependent on age and call type. Fmr1 KO pups showed an increased number of USVs at P7 but not at P4 or P10. This increase was specific to Frequency Jump calls. In addition, fmr1 KO mice showed a developmental shift in the temporal distribution of calls, with P10 mice calling in distinct bout patterns. Overall, these findings provide evidence that changes in USV outcomes were specific to certain call types and ages in fmr1 KO mice. Because early postnatal life is a window during which multiple neural systems activate and become established, behavioral measures such as using USVs as a measure of communication, may be useful as a predictor of brain changes and later developmental behavioral changes. Work is needed to better understand the functional outcomes of altered development of USVs and how these changes contribute to later emergence of autistic-like behaviors in animal models of autism.

Female and male adult brush mice (Peromyscus boylii) use ultrasonic vocalizations in the wild

We examined the individual context of ultrasonic vocalizations (USVs) produced by free-living wild male and female adult brush mice (Peromyscus boylii). We tested the hypothesis that USV production is dependent on behavioral context, and is important during both adult male and female interactions. Our methods included a 12-channel microphone array, radio-telemetry and thermal imaging that allowed us to determine: (1) who produced USVs, (2) characteristics of USVs, (3) type of USVs, (4) behavioral context of USVs and (5) the identity of the second mouse if an individual was not alone when a USV was produced. Females vocalized as much as males and produced the same types of USVs as males. There were no differences between spectral characteristics of male and female USVs. Females and males vocalized in the presence of one another. Importantly, when females were together they vocalized more than expected based on the proportion of time they spent together. Our results suggest that, in addition to facilitating courtship and mating, USVs are general territorial calls for neighbors because females vocalized in the presence of their neighbors. Despite a large literature on laboratory mouse (Mus musculus) USVs, studies are heavily biased towards males. Our results on brush mice, a species with a similar breeding system to the lab mouse and other rodents, suggest that female–female communication is an important and underappreciated component of the evolution and maintenance of mouse USVs.

CALL FOR INTERACTION OF ULTRASOUND IN RATS

The article presents data illustrating the changes in the characteristics of ultrasonic vocalizations in rats (mean frequency, duration and power ranges of ultrasonic waves) in acute emotional stressor impact. In the ultrasonic vocalizations of rats reflects individual motivation emotive, dominating at a certain time. These data illustrate the importance of ultrasound information in mammals.

A comparison of prairie vole audible and ultrasonic pup calls and attraction to them by adults of each sex

AbstractRodent pups of many species emit both ultrasonic vocalizations (USVs) and calls spanning into a lower frequency range, audible to humans (AUDs), yet there has been little systematic comparison of these different call types, or analyses of how they might differ in signal function. Here the spectral and temporal characteristics of USV and AUD pup calls are described for the prairie vole (Microtus ochrogaster), a model used in studies of monogamous mating and biparental care, and a species with an unusually large functional and anatomical representation of auditory cortex. Findings provide a detailed description of each call type, including changes to a number of USV characteristics over pup development. Adult attraction to the playback of these two call types was tested in groups that differed in regards to sex and reproductive status. Separate groups included virgins as well as paired animals of each sex, tested at time points either prior to the birth of pups (associated with either mid or late gestation), or at postpartum time points (parents of 2–3 day olds and parents of 8–9 day olds). Adults were attracted to both USVs and AUDs, but group differences were found only in the attraction to USVs. Males were more attracted to USVs than females, and there were interactions of sex and reproductive status. Results suggest that pup vocal communication is quite sophisticated, and that USVs and AUDs may have different communicative functions.

Influence of acute caffeine on 50-kHz ultrasonic vocalizations in male adult rats and relevance to caffeine-mediated psychopharmacological effects

To further characterize caffeine-mediated psychopharmacological effects, the present study investigated whether acute caffeine (3, 10, 30, 50 mg/kg i.p.) exerted any influence on the emission and features of ultrasonic vocalizations (USVs), which are thought to index changes involving emotional state, in male adult rats. The results obtained demonstrate that caffeine can trigger modifications in the maximum peak frequency and bandwidth of the 50-kHz range USVs. However, such an effect was not accompanied by a significant elevation in the number of 50-kHz USVs, relative to administration of vehicle. Under the same experimental conditions, acute amphetamine (2 mg/kg i.p.) robustly elevated the number of 50-kHz USVs emitted by rats, although it did not affect the maximum peak frequency and bandwidth of USVs. Thus, both qualitative and quantitative differences in the effects exerted by caffeine and amphetamine on 50-kHz USVs were observed. Taken together, these findings further clarify the features of caffeine-mediated psychopharmacological effects, and may help to elucidate the differences between the central effects of caffeine and those elicited by other psychostimulants.