Animal Models of Speech and Vocal Communication Deficits Associated With Psychiatric Disorders

Activity of forkhead box P2-positive neurons is associated with tadpole begging behaviour

Motor function is a critical aspect of social behaviour in a wide range of taxa. The transcription factor forkhead box P2 (FoxP2) is well studied in the context of vocal communication in humans, mice and songbirds, but its role in regulating social behaviour in other vertebrate taxa is unclear. We examined the distribution and activity of FoxP2-positive neurons in tadpoles of the mimic poison frog (Ranitomeya imitator). In this species, tadpoles are reared in isolated plant nurseries and are aggressive to other tadpoles. Mothers provide unfertilized egg meals to tadpoles that perform a begging display by vigorously vibrating back and forth. We found that FoxP2 is widely distributed in the tadpole brain and parallels the brain distribution in mammals, birds and fishes. We then tested the hypothesis that FoxP2-positive neurons would have differential activity levels in begging or aggression contexts compared to non-social controls. We found that FoxP2-positive neurons showed increased activation in the striatum and cerebellum during begging and in the nucleus accumbens during aggression. Overall, these findings lay a foundation for testing the hypothesis that FoxP2 has a generalizable role in social behaviour beyond vocal communication across terrestrial vertebrates.

Activity of FoxP2-positive neurons is associated with tadpole begging behavior

Motor function is a critical aspect of social behavior in a wide range of taxa. The transcription factor FoxP2 is well studied in the context of vocal communication in humans, mice, and songbirds, but its role in regulating social behavior in other vertebrate taxa is unclear. We examined the distribution and activity of FoxP2-positive neurons in tadpoles of the mimic poison frog (Ranitomeya imitator). In this species, tadpoles are reared in isolated plant nurseries and are aggressive to other tadpoles. Mothers provide unfertilized egg meals to tadpoles that perform a begging display by vigorously vibrating back and forth. We found that FoxP2 is widely distributed in the tadpole brain and parallels the brain distribution in mammals, birds, and fishes. We then tested the hypothesis that FoxP2-positive neurons would have differential activity levels in begging or aggression contexts compared to non-social controls. We found that FoxP2-positive neurons showed increased activation in the striatum and cerebellum during begging and in the nucleus accumbens during aggression. Overall, these findings lay a foundation for testing the hypothesis that FoxP2 has a generalizable role in social behavior beyond vocal communication across terrestrial vertebrates.

Compensation between FOXP transcription factors maintains proper striatal function

Spiny projection neurons (SPNs) of the striatum are critical in integrating neurochemical information to coordinate motor and reward-based behavior. Mutations in the regulatory transcription factors expressed in SPNs can result in neurodevelopmental disorders (NDDs). Paralogous transcription factors Foxp1 and Foxp2, which are both expressed in the dopamine receptor 1 (D1) expressing SPNs, are known to have variants implicated in NDDs. Utilizing mice with a D1-SPN-specific loss of Foxp1, Foxp2, or both and a combination of behavior, electrophysiology, and cell-type-specific genomic analysis, loss of both genes results in impaired motor and social behavior as well as increased firing of the D1-SPNs. Differential gene expression analysis implicates genes involved in autism risk, electrophysiological properties, and neuronal development and function. Viral-mediated re-expression of Foxp1 into the double knockouts is sufficient to restore electrophysiological and behavioral deficits. These data indicate complementary roles between Foxp1 and Foxp2 in the D1-SPNs.

Characterization of Ultrasonic Vocalization-Modulated Neurons in Rat Motor Cortex Based on Their Activity Modulation and Axonal Projection to the Periaqueductal Gray

Vocalization, a means of social communication, is prevalent among many species, including humans. Both rats and mice use ultrasonic vocalizations (USVs) in various social contexts and affective states. The motor cortex is hypothesized to be involved in precisely controlling USVs through connections with critical regions of the brain for vocalization, such as the periaqueductal gray matter (PAG). However, it is unclear how neurons in the motor cortex are modulated during USVs. Moreover, the relationship between USV modulation of neurons and anatomical connections from the motor cortex to PAG is also not clearly understood. In this study, we first characterized the activity patterns of neurons in the primary and secondary motor cortices during emission of USVs in rats using large-scale electrophysiological recordings. We also examined the axonal projection of the motor cortex to PAG using retrograde labeling and identified two clusters of PAG-projecting neurons in the anterior and posterior parts of the motor cortex. The neural activity patterns around the emission of USVs differed between the anterior and posterior regions, which were divided based on the distribution of PAG-projecting neurons in the motor cortex. Furthermore, using optogenetic tagging, we recorded the USV modulation of PAG-projecting neurons in the posterior part of the motor cortex and found that they showed predominantly sustained excitatory responses during USVs. These results contribute to our understanding of the involvement of the motor cortex in the generation of USV at the neuronal and circuit levels.

Stuttering as a spectrum disorder: A hypothesis

Childhood-onset fluency disorder, commonly referred to as stuttering, affects over 70 million adults worldwide. While stuttering predominantly initiates during childhood and is more prevalent in males, it presents consistent symptoms during conversational speech. Despite these common clinical manifestations, evidence suggests that stuttering, may arise from different etiologies, emphasizing the need for personalized therapy approaches. Current research models often regard the stuttering population as a singular, homogenous group, potentially overlooking the inherent heterogeneity. This perspective consolidates both historical and recent observations to emphasize that stuttering is a heterogeneous condition with diverse causes. As such, it is crucial that both therapeutic research and clinical practices consider the potential for varied etiologies leading to stuttering. Recognizing stuttering as a spectrum disorder embraces its inherent variability, allowing for a more nuanced categorization of individuals based on the underlying causes. This perspective aligns with the principles of precision medicine, advocating for tailored treatments for distinct subgroups of people who stutter, ultimately leading to personalized therapeutic approaches.

Speech- and language-linked FOXP2 mutation targets protein motors in striatal neurons

Human speech and language are among the most complex motor and cognitive abilities. The discovery of a mutation in the transcription factor FOXP2 in KE family members with speech disturbances has been a landmark example of the genetic control of vocal communication in humans. Cellular mechanisms underlying this control have remained unclear. By leveraging FOXP2 mutation/deletion mouse models, we found that the KE family FOXP2R553H mutation directly disables intracellular dynein-dynactin 'protein motors' in the striatum by induction of a disruptive high level of dynactin1 that impairs TrkB endosome trafficking, microtubule dynamics, dendritic outgrowth and electrophysiological activity in striatal neurons alongside vocalization deficits. Dynactin1 knockdown in mice carrying FOXP2R553H mutations rescued these cellular abnormalities and improved vocalization. We suggest that FOXP2 controls vocal circuit formation by regulating protein motor homeostasis in striatal neurons, and that its disruption could contribute to the pathophysiology of FOXP2 mutation/deletion-associated speech disorders.

Compensation between FOXP transcription factors maintains proper striatal function

Spiny projection neurons (SPNs) of the striatum are critical in integrating neurochemical information to coordinate motor and reward-based behavior. Mutations in the regulatory transcription factors expressed in SPNs can result in neurodevelopmental disorders (NDDs). Paralogous transcription factors Foxp1 and Foxp2, which are both expressed in the dopamine receptor 1 (D1) expressing SPNs, are known to have variants implicated in NDDs. Utilizing mice with a D1-SPN specific loss of Foxp1, Foxp2, or both and a combination of behavior, electrophysiology, and cell-type specific genomic analysis, loss of both genes results in impaired motor and social behavior as well as increased firing of the D1-SPNs. Differential gene expression analysis implicates genes involved in autism risk, electrophysiological properties, and neuronal development and function. Viral mediated re-expression of Foxp1 into the double knockouts was sufficient to restore electrophysiological and behavioral deficits. These data indicate complementary roles between Foxp1 and Foxp2 in the D1-SPNs.

Cataracts Across the Tree of Life: A Roadmap for Prevention and Biomedical Innovation

PURPOSE

Spontaneous cataracts have been identified in the lenses of animals across a phylogenetically wide range of species. This can be a source of insights and innovation for human health professionals, but many persons may lack awareness of it. By providing a phylogenetic survey and analysis of species with cataract vulnerability, this paper demonstrates how a broad comparative perspective can provide critical information about environmental hazards to human visual health and can spark potential innovations in the prevention and treatment of cataracts in humans.

DESIGN

Perspectives.

METHODS

Review and synthesis of selected literature with interpretation and perspective.

RESULTS

We found 273 recorded cases of spontaneously occurring cataracts in 113 species of birds, 83 species of mammals, 30 species of actinopterygii fish, 10 species of amphibians, 6 species of reptiles, and 1 species of cephalopod.

CONCLUSION

A phylogenetically wide range of species, including many living in and around human environments, are vulnerable to cataracts. These animals may serve as sentinels for human visual health. Variation in cataract vulnerability across species may also facilitate the identification of resistance-conferring physiologies, leading to accelerated innovation in the prevention and treatment of cataracts in humans.

Spontaneously hypertensive rats manifest deficits in emotional response to 22-kHz and 50-kHz ultrasonic playback

Many symptoms used routinely for human psychiatric diagnosis cannot be directly observed in animals which cannot describe their internal states. However, the ultrasonic vocalizations (USV) rodents use to communicate their emotional states can be measured. USV have therefore become a particularly useful tool in brain disease models. Spontaneously hypertensive rats (SHR) are considered an animal model of attention deficit hyperactivity disorder (ADHD) and schizophrenia. However, the specifics of SHR's behavior have not been fully described and there is very little data on their USV. Recently, we developed a communication model, in which Wistar rats are exposed to pre-recorded playbacks of aversive (22-kHz) or appetitive (50-kHz) USV, and their vocal responses depend on the extent of prior fear conditioning (0, 1, 6 or 10 shocks). Here, we investigated SHR's behavior and heart rate (HR) in our communication model, in comparison to Wistar rats employed as controls. In general, SHR emitted typical USV categories, however, they contained more short 22-kHz and less 50-kHz USV overall. Moreover, fewer SHR, in comparison with Wistar rats, emitted long 22-kHz USV after fear conditioning. SHR did not show a 50-kHz playback-induced HR increase, while they showed a profound 22-kHz playback-induced HR decrease. Finally, the number of previously delivered conditioning shocks appeared to have no effect on the investigated vocal, locomotor and HR responses of SHR. The phenomena observed in SHR are potentially attributable to deficits in emotional perception and processing. A lower number of 50-kHz USV emitted by SHR may reflect observations of speech impairments in human patients and further supports the usefulness of SHR to model ADHD and schizophrenia.

Acoustic camera system for measuring ultrasound communication in mice

To investigate biological mechanisms underlying social behaviors and their deficits, social communication via ultrasonic vocalizations (USVs) in mice has received considerable attention as a powerful experimental model. The advances in sound localization technology have facilitated the analysis of vocal interactions between multiple mice. However, existing sound localization systems are built around distributed-microphone arrays, which require a special recording arena and long processing time. Here, we report a novel acoustic camera system, USVCAM, which enables simpler and faster USV localization and assignment. The system comprises recently developed USV segmentation algorithms with a modification for overlapping vocalizations that results in high accuracy. Using USVCAM, we analyzed USV communications in a conventional home cage, and demonstrated novel vocal interactions in female ICR mice under a resident-intruder paradigm. The extended applicability and usability of USVCAM may facilitate future studies investigating typical and atypical vocal communication and social behaviors, as well as the underlying mechanisms.

Gaining insights into the internal states of the rodent brain through vocal communications

Animals display various behaviors during social interactions. Social behaviors have been proposed to be driven by the internal states of the animals, reflecting their emotional or motivational states. However, the internal states that drive social behaviors are complex and difficult to interpret. Many animals, including mice, use vocalizations for communication in various social contexts. This review provides an overview of current understandings of mouse vocal communications, its underlying neural circuitry, and the potential to use vocal communications as a readout for the animal's internal states during social interactions.

Autism-linked gene FoxP1 selectively regulates the cultural transmission of learned vocalizations

Autism spectrum disorders (ASDs) are characterized by impaired learning of social skills and language. Memories of how parents and other social models behave are used to guide behavioral learning. How ASD-linked genes affect the intertwined aspects of observational learning and behavioral imitation is not known. Here, we examine how disrupted expression of the ASD gene FOXP1, which causes severe impairments in speech and language learning, affects the cultural transmission of birdsong between adult and juvenile zebra finches. FoxP1 is widely expressed in striatal-projecting forebrain mirror neurons. Knockdown of FoxP1 in this circuit prevents juvenile birds from forming memories of an adult song model but does not interrupt learning how to vocally imitate a previously memorized song. This selective learning deficit is associated with potent disruptions to experience-dependent structural and synaptic plasticity in mirror neurons. Thus, FoxP1 regulates the ability to form memories essential to the cultural transmission of behavior.

Sex differences in vocalizations to familiar or unfamiliar females in mice

Mice, both wild and laboratory strains, emit ultrasound to communicate. The sex differences between male to female (male-female) and female to female (female-female) ultrasonic vocalizations (USVs) have been discussed for decades. In the present study, we compared the number of USVs emitted to familiar and unfamiliar females by both males (male-female USVs) and females (female-female USVs). We found that females vocalized more to unfamiliar than to familiar females. By contrast, males exhibited more USVs to familiar partners. This sexually dimorphic behaviour suggests that mice change their vocal behaviour in response to the social context, and their perception of the context is based on social cognition and memory. In addition, because males vocalized more to familiar females, USVs appear to be not only a response to novel objects or individuals, but also a social response.

FOXP transcription factors in vertebrate brain development, function, and disorders

FOXP transcription factors are an evolutionarily ancient protein subfamily coordinating the development of several organ systems in the vertebrate body. Association of their genes with neurodevelopmental disorders has sparked particular interest in their expression patterns and functions in the brain. Here, FOXP1, FOXP2, and FOXP4 are expressed in distinct cell type-specific spatiotemporal patterns in multiple regions, including the cortex, hippocampus, amygdala, basal ganglia, thalamus, and cerebellum. These varied sites and timepoints of expression have complicated efforts to link FOXP1 and FOXP2 mutations to their respective developmental disorders, the former affecting global neural functions and the latter specifically affecting speech and language. However, the use of animal models, particularly those with brain region- and cell type-specific manipulations, has greatly advanced our understanding of how FOXP expression patterns could underlie disorder-related phenotypes. While many questions remain regarding FOXP expression and function in the brain, studies to date have illuminated the roles of these transcription factors in vertebrate brain development and have greatly informed our understanding of human development and disorders. This article is categorized under: Nervous System Development > Vertebrates: General Principles Gene Expression and Transcriptional Hierarchies > Gene Networks and Genomics Nervous System Development > Vertebrates: Regional Development.

Angelman Syndrome: From Mouse Models to Therapy

The UBE3A gene is part of the chromosome 15q11-q13 region that is frequently deleted or duplicated, leading to several neurodevelopmental disorders (NDD). Angelman syndrome (AS) is caused by the absence of functional maternally derived UBE3A protein, while the paternal UBE3A gene is present but silenced specifically in neurons. Patients with AS present with severe neurodevelopmental delay, with pronounced motor deficits, absence of speech, intellectual disability, epilepsy, and sleep problems. The pathophysiology of AS is still unclear and a treatment is lacking. Animal models of AS recapitulate the genotypic and phenotypic features observed in AS patients, and have been invaluable for understanding the disease process as well as identifying apropriate drug targets. Using these AS mouse models we have learned that loss of UBE3A probably affects many areas of the brain, leading to increased neuronal excitability and a loss of synaptic spines, along with changes in a number of distinct behaviours. Inducible AS mouse models have helped to identify the critical treatment windows for the behavioral and physiological phenotypes. Additionally, AS mouse models indicate an important role for the predominantly nuclear UBE3A isoform in generating the characteristic AS pathology. Last, but not least, the AS mice have been crucial in guiding Ube3a gene reactivation treatments, which present a very promising therapy to treat AS.

USVSEG: A robust method for segmentation of ultrasonic vocalizations in rodents

Rodents' ultrasonic vocalizations (USVs) provide useful information for assessing their social behaviors. Despite previous efforts in classifying subcategories of time-frequency patterns of USV syllables to study their functional relevance, methods for detecting vocal elements from continuously recorded data have remained sub-optimal. Here, we propose a novel procedure for detecting USV segments in continuous sound data containing background noise recorded during the observation of social behavior. The proposed procedure utilizes a stable version of the sound spectrogram and additional signal processing for better separation of vocal signals by reducing the variation of the background noise. Our procedure also provides precise time tracking of spectral peaks within each syllable. We demonstrated that this procedure can be applied to a variety of USVs obtained from several rodent species. Performance tests showed this method had greater accuracy in detecting USV syllables than conventional detection methods.

Memory circuits for vocal imitation

Many complex behaviors exhibited by social species are first learned by imitating the behavior of other more experienced individuals. Speech and language are the most widely appreciated behaviors learned in this way. Vocal imitation in songbirds is perhaps the best studied socially transmitted behavior, and research over the past few years has begun to crack the circuit mechanisms for how songbirds learn from vocal models. Studies in zebra finches are revealing an unexpected and essential role for premotor cortical circuits in forming the behavioral-goal memories used to guide song imitation, challenging the view that song memories used for imitation are stored in auditory circuits. Here, we provide a summary of this recent progress focusing on the What, Where, and How of tutor song memory, and propose a circuit hypothesis for song learning based on these recent findings.

Corollary Discharge Mechanisms During Vocal Production in Marmoset Monkeys

Interactions between motor systems and sensory processing are ubiquitous throughout the animal kingdom and play an important role in many sensorimotor behaviors, including both human speech and animal vocalization. During vocal production, the auditory system plays important roles in both encoding feedback of produced sounds, allowing one to self-monitor for vocal errors, and simultaneously maintaining sensitivity to the outside acoustic environment. Supporting these roles is an efferent motor-to-sensory signal known as a corollary discharge. This review summarizes recent work on the role of such signaling during vocalization in the marmoset monkey, a nonhuman primate model of social vocal communication.

Effect of Sociosexual Experience and Aging on Number of Courtship Ultrasonic Vocalizations in Male Mice

Sexual behaviors are instinctually exhibited without prior training, but they are modulated by experience. One of the precopulatory behaviors in adult male mice, courtship ultrasonic vocalizations (USVs), has attracted considerable academic attention recently. Male mice emit ultrasounds as courtship behavior when encountering females. However, the modulatory effects of experience on USVs remain unclear. In the present study, we aimed to clarify the effects of sociosexual experience and aging on adult male vocalizations. First, we examined the effect of aging. The number of USVs decreased in an age-dependent manner. Following this, young adult male mice were co-housed for two weeks with normal female mice or ovariectomized (OVX) female mice, or housed without female mice, and the number of courtship USVs before and after co-housing were compared. In males housed with normal or OVX females, USVs increased significantly after co-housing. In contrast, males housed without females did not exhibit a significant increase of USVs. A facilitative effect of co-housing with female mice on vocalizations was also observed in aged males. In addition, females used as co-housing partners became pregnant, and the reproductive rate may be related to the vocal activity observed in the partnered males. These results indicate that sociosexual experience and aging affect vocalization activity, which may be related to courtship and/or reproductive function.

Using Temporal Expectation to Assess Auditory Streaming in Mice

Auditory streaming is the process by which environmental sound is segregated into discrete perceptual objects. The auditory system has a remarkable capability in this regard as revealed in psychophysical experiments in humans and other primates. However, little is known about the underlying neuronal mechanisms, in part because of the lack of suitable behavioural paradigms in non-primate species. The mouse is an increasingly popular model for studying the neural mechanisms of perception and action because of the range of molecular tools enabling precise manipulation of neural circuitry. Here we present a novel behavioural task that can be used to assess perceptual aspects of auditory streaming in head-fixed mice. Animals were trained to detect a target sound in a one of two simultaneously presented, isochronous pure tone sequences. Temporal expectation was manipulated by presenting the target sound in a particular stream either early (~2 s) or late (~4 s) with respect to trial onset in blocks of 25-30 trials. Animals reached high performance on this task (d' > 1 overall), and notably their false alarms were very instructive of their behavioural state. Indeed, false alarm timing was markedly delayed for late blocks compared to early ones, indicating that the animals associated a different context to an otherwise identical stimulus. More finely, we observed that the false alarms were timed to the onset of the sounds present in the target stream. This suggests that the animals could selectively follow the target stream despite the presence of a distractor stream. Extracellular electrophysiological recordings during the task revealed that sound processing is flexibly modulated in a manner consistent with the optimisation of behavioural outcome. Together, these results indicate that the perceptual streaming can be inferred via the timing of false alarms in mice, and provide a new paradigm with which to investigate neuronal mechanisms of selective attention.

Vocalisation as a Viable Assessment for Phenotyping Minipigs Transgenic for the Huntington Gene?

BACKGROUND

Large animal models, such as the transgenic (tg) Huntington disease (HD) minipig, have been proposed to improve translational reliability and assessment of safety, efficacy and tolerability in preclinical studies. Minipigs are characterised by high genetic homology and comparable brain structures to humans. In addition, behavioural assessments successfully applied in humans could be explored in minipigs to establish similar endpoints in preclinical and clinical studies. Recently, analysis of voice and speech production was established to characterise HD patients.

OBJECTIVE

The aim of this study was to investigate whether vocalisation could also serve as a viable marker for phenotyping minipigs transgenic for Huntington's disease (tgHD) and whether tgHD minipigs reveal changes in this domain compared to wildtype (wt) minipigs.

METHODS

While conducting behavioural testing, incidence of vocalisation was assessed for a cohort of 14 tgHD and 18 wt minipigs. Statistical analyses were performed using Fisher's Exact Test for group comparisons and McNemar's Test for intra-visit differences between tgHD and wt minipigs.

RESULTS

Vocalisation can easily be documented during phenotyping assessments of minipigs. Differences in vocalisation incidences across behavioural conditions were detected between tgHD and wt minipigs. Influence of the genotype on vocalisation was detectable during a period of 1.5 years.

CONCLUSION

Vocalisation may be a viable marker for phenotyping minipigs transgenic for the Huntington gene. Documentation of vocalisation provides a non-invasive opportunity to capture potential disease signs and explore phenotypic development including the age of disease manifestation.

A Basal Ganglia Circuit Sufficient to Guide Birdsong Learning

Learning vocal behaviors, like speech and birdsong, is thought to rely on continued performance evaluation. Whether candidate performance evaluation circuits in the brain are sufficient to guide vocal learning is not known. Here, we test the sufficiency of VTA projections to the vocal basal ganglia in singing zebra finches, a songbird species that learns to produce a complex and stereotyped multi-syllabic courtship song during development. We optogenetically manipulate VTA axon terminals in singing birds contingent on how the pitch of an individual song syllable is naturally performed. We find that optical inhibition and excitation of VTA terminals are each sufficient to reliably guide learned changes in song. Inhibition and excitation have opponent effects on future performances of targeted song syllables, consistent with positive and negative reinforcement of performance outcomes. These findings define a central role for reinforcement mechanisms in learning vocalizations and demonstrate minimal circuit elements for learning vocal behaviors. VIDEO ABSTRACT.

Foxp1 regulation of neonatal vocalizations via cortical development

Usui et al. show that deletion of Foxp1 in the developing forebrain leads to impairments in neonatal vocalizations as well as neocortical cytoarchitectonic alterations via neuronal positioning and migration. Sumoylation of Foxp1 affects neuronal differentiation and migration in the developing neocortex.

The molecular mechanisms driving brain development at risk in autism spectrum disorders (ASDs) remain mostly unknown. Previous studies have implicated the transcription factor FOXP1 in both brain development and ASD pathophysiology. However, the specific molecular pathways both upstream of and downstream from FOXP1 are not fully understood. To elucidate the contribution of FOXP1-mediated signaling to brain development and, in particular, neocortical development, we generated forebrain-specific Foxp1 conditional knockout mice. We show that deletion of Foxp1 in the developing forebrain leads to impairments in neonatal vocalizations as well as neocortical cytoarchitectonic alterations via neuronal positioning and migration. Using a genomics approach, we identified the transcriptional networks regulated by Foxp1 in the developing neocortex and found that such networks are enriched for downstream targets involved in neurogenesis and neuronal migration. We also uncovered mechanistic insight into Foxp1 function by demonstrating that sumoylation of Foxp1 during embryonic brain development is necessary for mediating proper interactions between Foxp1 and the NuRD complex. Furthermore, we demonstrated that sumoylation of Foxp1 affects neuronal differentiation and migration in the developing neocortex. Together, these data provide critical mechanistic insights into the function of FOXP1 in the developing neocortex and may reveal molecular pathways at risk in ASD.

Lentiviral-Mediated Transgenesis in Songbirds

Transgenesis involves the insertion of an exogenous gene into an animal's genome, which allows the identification of the expressed phenotypes in brain function or behavior. Lentiviral-mediated transgenesis offers unique transduction potency making it possible to deliver and stably integrate transgenes into a wide variety of dividing and nondividing cells. The ability to establish long-term expression of such transgenes allows their use for transgenesis which is especially useful in organisms lacking quality pluripotent stem cell lines and which is otherwise difficult to produce via traditional pronuclear microinjection, such as songbirds. Here we describe a protocol to generate the transgenic songbird, the zebra finch, by producing and inserting lentiviral-mediated transgene into the blastoderm of freshly laid eggs. This protocol includes procedures for production of lentiviral vectors, injection of a virus into zebra finch embryos, and postinjection care. The implementation of the songbird transgenic approach provides a leap toward basic and translational neuroscience that uses an animal model for speech and language and their pathologies. Additionally, the highly quantifiable song behavior, combined with a well-characterized song circuitry, offers an exciting opportunity to develop therapeutic strategies for neurological disorders.

MUPET-Mouse Ultrasonic Profile ExTraction: A Signal Processing Tool for Rapid and Unsupervised Analysis of Ultrasonic Vocalizations

Vocalizations play a significant role in social communication across species. Analyses in rodents have used a limited number of spectro-temporal measures to compare ultrasonic vocalizations (USVs), which limits the ability to address repertoire complexity in the context of behavioral states. Using an automated and unsupervised signal processing approach, we report the development of MUPET (Mouse Ultrasonic Profile ExTraction) software, an open-access MATLAB tool that provides data-driven, high-throughput analyses of USVs. MUPET measures, learns, and compares syllable types and provides an automated time stamp of syllable events. Using USV data from a large mouse genetic reference panel and open-source datasets produced in different social contexts, MUPET analyzes the fine details of syllable production and repertoire use. MUPET thus serves as a new tool for USV repertoire analyses, with the capability to be adapted for use with other species.

Arid1b haploinsufficient mice reveal neuropsychiatric phenotypes and reversible causes of growth impairment

Sequencing studies have implicated haploinsufficiency of ARID1B, a SWI/SNF chromatin-remodeling subunit, in short stature (Yu et al., 2015), autism spectrum disorder (O'Roak et al., 2012), intellectual disability (Deciphering Developmental Disorders Study, 2015), and corpus callosum agenesis (Halgren et al., 2012). In addition, ARID1B is the most common cause of Coffin-Siris syndrome, a developmental delay syndrome characterized by some of the above abnormalities (Santen et al., 2012; Tsurusaki et al., 2012; Wieczorek et al., 2013). We generated Arid1b heterozygous mice, which showed social behavior impairment, altered vocalization, anxiety-like behavior, neuroanatomical abnormalities, and growth impairment. In the brain, Arid1b haploinsufficiency resulted in changes in the expression of SWI/SNF-regulated genes implicated in neuropsychiatric disorders. A focus on reversible mechanisms identified Insulin-like growth factor (IGF1) deficiency with inadequate compensation by Growth hormone-releasing hormone (GHRH) and Growth hormone (GH), underappreciated findings in ARID1B patients. Therapeutically, GH supplementation was able to correct growth retardation and muscle weakness. This model functionally validates the involvement of ARID1B in human disorders, and allows mechanistic dissection of neurodevelopmental diseases linked to chromatin-remodeling.

A Diagnostic Marker to Discriminate Childhood Apraxia of Speech From Speech Delay: I. Development and Description of the Pause Marker

Purpose

The goal of this article (PM I) is to describe the rationale for and development of the Pause Marker (PM), a single-sign diagnostic marker proposed to discriminate early or persistent childhood apraxia of speech from speech delay.

Method

The authors describe and prioritize 7 criteria with which to evaluate the research and clinical utility of a diagnostic marker for childhood apraxia of speech, including evaluation of the present proposal. An overview is given of the Speech Disorders Classification System, including extensions completed in the same approximately 3-year period in which the PM was developed.

Results

The finalized Speech Disorders Classification System includes a nosology and cross-classification procedures for childhood and persistent speech disorders and motor speech disorders (Shriberg, Strand, & Mabie, 2017). A PM is developed that provides procedural and scoring information, and citations to papers and technical reports that include audio exemplars of the PM and reference data used to standardize PM scores are provided.

Conclusions

The PM described here is an acoustic-aided perceptual sign that quantifies one aspect of speech precision in the linguistic domain of phrasing. This diagnostic marker can be used to discriminate early or persistent childhood apraxia of speech from speech delay.

Amygdalar Auditory Neurons Contribute to Self-Other Distinction during Ultrasonic Social Vocalization in Rats

Although, clinical studies reported hyperactivation of the auditory system and amygdala in patients with auditory hallucinations (hearing others' but not one's own voice, independent of any external stimulus), neural mechanisms of self/other attribution is not well understood. We recorded neuronal responses in the dorsal amygdala including the lateral amygdaloid nucleus to ultrasonic vocalization (USVs) emitted by subjects and conspecifics during free social interaction in 16 adult male rats. The animals emitting the USVs were identified by EMG recordings. One-quarter of the amygdalar neurons (15/60) responded to 50 kHz calls by the subject and/or conspecifics. Among the responsive neurons, most neurons (Type-Other neurons; 73%, 11/15) responded only to calls by conspecifics but not subjects. Two Type-Self neurons (13%, 2/15) responded to calls by the subject but not those by conspecifics, although their response selectivity to subjects vs. conspecifics was lower than that of Type-Other neurons. The remaining two neurons (13%) responded to calls by both the subject and conspecifics. Furthermore, population coding of the amygdalar neurons represented distinction of subject vs. conspecific calls. The present results provide the first neurophysiological evidence that the amygdala discriminately represents affective social calls by subject and conspecifics. These findings suggest that the amygdala is an important brain region for self/other attribution. Furthermore, pathological activation of the amygdala, where Type-Other neurons predominate, could induce external misattribution of percepts of vocalization.

Insights into the Neural and Genetic Basis of Vocal Communication

The use of vocalizations to communicate information and elaborate social bonds is an adaptation seen in many vertebrate species. Human speech is an extreme version of this pervasive form of communication. Unlike the vocalizations exhibited by the majority of land vertebrates, speech is a learned behavior requiring early sensory exposure and auditory feedback for its development and maintenance. Studies in humans and a small number of other species have provided insights into the neural and genetic basis for learned vocal communication and are helping to delineate the roles of brain circuits across the cortex, basal ganglia, and cerebellum in generating vocal behaviors. This Review provides an outline of the current knowledge about these circuits and the genes implicated in vocal communication, as well as a perspective on future research directions in this field.

A momentary biomarker for depressive mood

Many biomarkers from genetic, neuroimaging, and biological/biochemical measures have been recently developed in order to make a shift toward the objective evaluation of psychiatric disorders. However, they have so far been less successful in capturing dynamical changes or transitions in pathological states, such as those occurring during the course of clinical treatments or pathogenic processes of disorders. A momentary biomarker is now required for objective monitoring of such dynamical changes. The development of ecological momentary assessment (EMA) allows the assessment of dynamical aspects of diurnal/daily clinical conditions and subjective symptoms. Furthermore, a variety of validation studies on momentary symptoms assessed by EMA using behavioral/physiological/biochemical measures have demonstrated the possibility of evaluating momentary symptoms from such external objective measures. In this review, we introduce physical activity as a candidate biobehavioral biomarker for psychiatric disorders. We also mention its potential as a momentary biomarker for depressive mood. Finally, we address the continuous monitoring of the pathogenic processes and pathological states of depressive disorders based on physical activity, as well as its application in pharmacological animal studies.