Effects of Congenital Blindness on Ultrasonic Vocalizations and Social Behaviors in the ZRDBA Mouse.

Mice produce ultrasonic vocalizations (USVs) at different ages and social contexts, including maternal-pup separation, social play in juveniles, social interactions, and mating in adults. The USVs' recording can be used as an index of sensory detection, internal state, and social motivation. While sensory deprivation may alter USVs' emission and some social behaviors in deaf and anosmic rodents, little is known about the effects of visual deprivation in rodents. This longitudinal study aimed to assess acoustic communication and social behaviors using a mouse model of congenital blindness. Anophthalmic and sighted mice were assayed to a series of behavioral tests at three different ages, namely, the maternal isolation-induced pup USV test and the home odor discrimination and preference test on postnatal day (PND) 7, the juvenile social test on PND 30-35, and the female urine-induced USVs and scent-marking behavior at 2-3 months. Our results evidenced that (1) at PND 7, USVs' total number between both groups was similar, all mice vocalized less during the second isolation period than the first period, and both phenotypes showed similar discrimination and preference, favoring exploration of the home bedding odor; (2) at PND 30-35, anophthalmic mice engaged less in social behaviors in the juvenile play test than sighted ones, but the number of total USVs produced is not affected; and (3) at adulthood, when exposed to a female urine spot, anophthalmic male mice displayed faster responses in terms of USVs' emission and sniffing behavior, associated with a longer time spent exploring the female urinary odor. Interestingly, acoustic behavior in the pups and adults was correlated in sighted mice only. Together, our study reveals that congenital visual deprivation had no effect on the number of USVs emitted in the pups and juveniles, but affected the USVs' emission in the adult male and impacted the social behavior in juvenile and adult mice.

Anxiety and Depression Assessments in a Mouse Model of Congenital Blindness.

Previous studies have reported that visual impairment can affect the quality of life leading to mental health disorders. This study aimed to investigate associations between vision impairment, depression and anxiety using a mouse model of congenital blindness. We phenotyped 15 anophthalmic and 17 sighted adult mice in a battery of tests for anxiety and depression-like behaviors: open field test, elevated plus maze, coated test, splash test, and forced swim test. We found that: (1) Anxiety levels of the anophthalmic mice were significantly lower when compared with sighted mice, (2) Anophthalmic mice displayed more exploratory behaviors in a new environment than the sighted one, and (3) Depression levels between those groups were similar. In conclusion, this behavioral study showed that early visual deprivation lowers anxiety levels, associated with heightened exploratory activity, but does not induce depressive symptoms in a mouse model of congenital blindness, underlying several behavioral adaptations.

Role of environmental factors and epigenetics in autism spectrum disorders.

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder thought to be caused by predisposing high-risk genes that may be altered during the early development by environmental factors. The impact of maternal challenges during pregnancy on the prevalence of ASD has been widely studied in clinical and animal studies. Here, we review some clinical and pre-clinical evidence that links environmental factors (i.e., infection, air pollution, pesticides, valproic acid and folic acid) and the risk of ASD. Additionally, certain prenatal environmental challenges such as the valproate and folate prenatal exposures allow us to study mechanisms possibly linked to the etiology of ASD, for instance the epigenetic processes. These mechanistic pathways are also presented and discussed in this chapter.

Development of a standardized method to evaluate the protective efficiency of cosmetic packaging against microbial contamination.

Doubts surrounding the potential adverse effects of antimicrobial preservatives have modified the demand of consumers, who increasingly insist on the production of low-level and even preservative-free cosmetics. Protection of the product against microbial contamination is therefore focused on the packaging. This has prompted the emergence of a highly diverse array of so-called "protective", "overprotective", and "barrier" packaging. However, these designations are not normalized and the choice of the right packaging adapted to each cosmetic product is still essentially empirical, hazardous, and time consuming. The Cosmetic Valleys cluster has launched a commission to define a complete and experimentally-validated method to classify the level of protection of cosmetic packaging against microbial contamination. As reported herein, this required the development a specific bacteriostatic medium that can be used for 7 days and an in vitro procedure that reproduces in-use contamination and consumer practices. Based on tests performed on over 800 packages of different origin and performance characteristics, we propose a classification, divided into six grades, to differentiate the protective efficiency of cosmetic packaging. This work can be considered as a first step towards a regulatory text.

In utero exposure to valproic acid and autism--a current review of clinical and animal studies.

Valproic acid (VPA) is both an anti-convulsant and a mood stabilizer. Clinical studies over the past 40 years have shown that exposure to VPA in utero is associated with birth defects, cognitive deficits, and increased risk of autism. Two recent FDA warnings related to use of VPA in pregnancy emphasize the need to reevaluate its use clinically during child-bearing years. The emerging clinical evidence showing a link between VPA exposure and both cognitive function and risk of autism brings to the forefront the importance of understanding how VPA exposure influences neurodevelopment. In the past 10 years, animal studies have investigated anatomical, behavioral, molecular, and physiological outcomes related to in utero VPA exposure. Behavioral studies show that VPA exposure in both rats and mice leads to autistic-like behaviors in the offspring, including social behavior deficits, increased repetitive behaviors, and deficits in communication. Based on this work VPA maternal challenge in rodents has been proposed as an animal model to study autism. This model has both face and construct validity; however, like all animal models there are limitations to its translation to the clinical setting. Here we provide a review of clinical studies that examined pregnancy outcomes of VPA use as well as the related animal studies.

Reduced excitatory neurotransmission and mild autism-relevant phenotypes in adolescent Shank3 null mutant mice.

Mutations in the synaptic scaffolding protein gene SHANK3 are strongly implicated in autism and Phelan-McDermid 22q13 deletion syndrome. The precise location of the mutation within the Shank3 gene is key to its phenotypic outcomes. Here, we report the physiological and behavioral consequences of null and heterozygous mutations in the ankyrin repeat domain in Shank3 mice. Both homozygous and heterozygous mice showed reduced glutamatergic transmission and long-term potentiation in the hippocampus with more severe deficits detected in the homozygous mice. Three independent cohorts were evaluated for magnitude and replicability of behavioral endophenotypes relevant to autism and Phelan-McDermid syndrome. Mild social impairments were detected, primarily in juveniles during reciprocal interactions, while all genotypes displayed normal adult sociability on the three-chambered task. Impaired novel object recognition and rotarod performance were consistent across cohorts of null mutants. Repetitive self-grooming, reduced ultrasonic vocalizations, and deficits in reversal of water maze learning were detected only in some cohorts, emphasizing the importance of replication analyses. These results demonstrate the exquisite specificity of deletions in discrete domains within the Shank3 gene in determining severity of symptoms.

Communication impairments in mice lacking Shank1: reduced levels of ultrasonic vocalizations and scent marking behavior.

Autism is a neurodevelopmental disorder with a strong genetic component. Core symptoms are abnormal reciprocal social interactions, qualitative impairments in communication, and repetitive and stereotyped patterns of behavior with restricted interests. Candidate genes for autism include the SHANK gene family, as mutations in SHANK2 and SHANK3 have been detected in several autistic individuals. SHANK genes code for a family of scaffolding proteins located in the postsynaptic density of excitatory synapses. To test the hypothesis that a mutation in SHANK1 contributes to the symptoms of autism, we evaluated Shank1(-/-) null mutant mice for behavioral phenotypes with relevance to autism, focusing on social communication. Ultrasonic vocalizations and the deposition of scent marks appear to be two major modes of mouse communication. Our findings revealed evidence for low levels of ultrasonic vocalizations and scent marks in Shank1(-/-) mice as compared to wildtype Shank1(+/+) littermate controls. Shank1(-/-) pups emitted fewer vocalizations than Shank1(+/+) pups when isolated from mother and littermates. In adulthood, genotype affected scent marking behavior in the presence of female urinary pheromones. Adult Shank1(-/-) males deposited fewer scent marks in proximity to female urine than Shank1(+/+) males. Call emission in response to female urinary pheromones also differed between genotypes. Shank1(+/+) mice changed their calling pattern dependent on previous female interactions, while Shank1(-/-) mice were unaffected, indicating a failure of Shank1(-/-) males to learn from a social experience. The reduced levels of ultrasonic vocalizations and scent marking behavior in Shank1(-/-) mice are consistent with a phenotype relevant to social communication deficits in autism.

Mouse models of autism: testing hypotheses about molecular mechanisms.

Autism is a neurodevelopmental disorder that is currently diagnosed by the presence of three behavioral criteria (1) qualitative impairments in reciprocal social interactions, (2) deficits in communication, including delayed language and noninteractive conversation, and (3) motor stereotypies, repetitive behaviors, insistence on sameness, and restricted interests. This chapter describes analogous behavioral assays that have been developed for mice, including tests for social approach, reciprocal social interactions, olfactory communication, ultrasonic vocalizations, repetitive and perseverative behaviors, and motor stereotypies. Examples of assay applications to genetic mouse models of autism are provided. Robust endophenotypes that are highly relevant to the core symptoms of autism are enabling the search for the genetic and environmental causes of autism, and the discovery of effective treatments.

Female urine-induced male mice ultrasonic vocalizations, but not scent-marking, is modulated by social experience.

Despite the evidence for a communicative function of rodent scent marks and ultrasonic vocalizations, relatively little is known about the impact of social factors on these two forms of communication. Here, we tested the effects of two important social factors, prior exposure to a female and freshness of female urine, on male scent marks and ultrasonic vocalizations elicited by female urine. We also asked whether a recently reported strain difference between the highly social strain C57BL/6J (B6) and the mouse model of autism BTBR T+tf/J (BTBR) herein is specifically seen in response to female urine or also detectable in response to male urine traces. Results show that the emission of female urine-elicited ultrasonic vocalizations was dependent on previous female experience, while scent-marking behavior was not affected. A positive correlation was detected between scent-marking behavior and ultrasonic calling in the most biologically relevant context, male mice exposed to fresh female urine after female experience. Correlations were less prominent or missing in less biologically relevant contexts, e.g. in male mice exposed to fresh female urine without previous female experience, indicating that previous female experience is affecting both the emission of female urine-elicited ultrasonic vocalizations and the correlation between olfactory and acoustic communication. The strain difference in scent-marking behavior and ultrasonic calling between B6 and BTBR appears to be specific to female urine-elicited behavior as it was not seen in response to male urine traces, highlighting the relevance of the social context in which mouse communication is evaluated.

Fos protein expression in olfactory-related brain areas after learning and after reactivation of a slowly acquired olfactory discrimination task in the rat.

Fos protein immunodetection was used to investigate the neuronal activation elicited in some olfactory-related areas after either learning of an olfactory discrimination task or its reactivation 10 d later. Trained rats (T) progressively acquired the association between one odor of a pair and water-reward in a four-arm maze. Two groups of pseudotrained rats were used: PO rats were not water restricted and were submitted to the olfactory stimuli in the maze without any reinforcement, whereas PW rats were water-deprived and systematically received water in the maze without any odorous stimulation. When the discrimination task was well mastered, a significantly lower Fos immunoreactivity was observed in T rats compared to PW and PO rats in most of the analyzed brain areas, which could reflect the post-acquisition consolidation process. Following memory reactivation, differences in Fos immunoreactivity between trained and some pseudotrained rats were found in the anterior part of piriform cortex, CA3, and orbitofrontal cortex. We also observed that Fos labeling was significantly higher in trained rats after memory reactivation than after acquisition of the olfactory task in most of the brain areas examined. Our results support the assumption of a differential involvement of neuronal networks after either learning or reactivation of an olfactory discrimination task.

Learning-stage dependent Fos expression in the rat brain during acquisition of an olfactory discrimination task.

By using Fos immunocytochemistry, we investigated the activation in olfactory-related areas at three stages (the first and fourth days of conditioning and complete acquisition) of an olfactory discrimination learning task. The trained rats (T) had to associate one odour of a pair with water-reward within a four-arm maze whereas pseudo-trained (P) rats were only submitted to the olfactory cues without any reinforcement. In the piriform cortex, both T and P rats exhibited a higher immunoreactivity on the first day, which seemed to indicate a novelty-related Fos expression in this area, but whatever the learning-stage, no significant difference in Fos expression between T and P rats was observed. In hippocampus, Fos expression was significantly different between T and P rats in CA1 and CA3 on the first and fourth days respectively. Thus we showed a differential activation of CA1 and CA3 subfields which might support a possible functional heterogeneity. In the orbitofrontal cortex, Fos immunoreactivity was significantly higher in T rats compared to P rats when mastery of the discrimination task was complete. In contrast, no learning-related Fos expression was found in infralimbic and prelimbic cortices. The present data suggest an early implication of the hippocampal formation and a later involvement of neocortical areas throughout different stages of a progressively acquired olfactory learning task.

Cue valence representation studied by Fos immunocytochemistry after acquisition of a discrimination learning task.

The piriform cortex (PCx) and related structures such as hippocampus and frontal cortex could play an important role in olfactory memory. We investigated their involvement in learning the biological value of an odor cue, i.e. predicting reward or non-reward in a two-odor discrimination task. Rats were sacrificed after stimulation by either rewarded or non-rewarded odor and Fos immunocytochemistry was performed. The different experimental groups of rats did not show strongly differentiated Fos expression pattern in either the PCx or the hippocampus. A few differences were noted in frontal areas. In the ventro-lateral orbital cortex, rats, ramdomly rewarded during the conditionning had a higher Fos level in comparison with other groups. In infralimbic cortex, rats, which learned the reward value of the olfactory cue and were water-reinforced the day of sacrifice, showed a higher Fos expression. Data are discussed in view of the olfactory learning paradigm and of the accuracy of the control groups used in the present experimental design. The behavioural conditions leading to Fos expression are further discussed since Fos is a marker of learning-induced plasticity as well as a general activity marker which can be activated by a wide range of stimuli not directly linked to memory.