Inexpensive Home Infrared Living/Environment Sensor with Regional Thermal Information for Infant Physical and Psychological Development.

The use of home-based image sensors for biological and environmental monitoring provides novel insight into health and development but it is difficult to evaluate people during their normal activities in their home. Therefore, we developed a low-cost infrared (IR) technology-based motion, location, temperature and thermal environment detection system that can be used non-invasively for long-term studies in the home environment. We tested this technology along with the associated analysis algorithm to visualize the effects of parental care and thermal environment on developmental state change in a non-human primate model, the common marmoset (Callithrix jacchus). To validate this system, we first compared it to a manual analysis technique and we then assessed the development of circadian rhythms in common marmosets from postnatal day 15-45. The semi-automatically tracked biological indices of locomotion velocity (BV) and body surface temperature (BT) and the potential psychological index of place preference toward the door (BD), showed age-dependent shifts in circadian phase patterns. Although environmental variables appeared to affect circadian rhythm development, principal component analysis and signal superimposing imaging methods revealed a novel phasic pattern of BD-BT correlation day/night switching in animals older than postnatal day 38 (approximately equivalent to one year of age in humans). The origin of this switch was related to earlier development of body temperature (BT) rhythms and alteration of psychological behavior rhythms (BD) around earlier feeding times. We propose that this cost-effective, inclusive sensing and analytic technique has value for understanding developmental care conditions for which continual home non-invasive monitoring would be beneficial and further suggest the potential to adapt this technique for use in humans.

A Susceptible Period of Photic Day-Night Rhythm Loss in Common Marmoset Social Behavior Development.

The prevalence of neurodevelopmental psychiatric disorders such as pervasive developmental disorders is rapidly increasing worldwide. Although these developmental disorders are known to be influenced by an individual's genetic background, the potential biological responses to early life's environmental exposure to both physical and psychological factors must also be considered. Many studies have acknowledged the influence of shorter time for rest at night and the simultaneous occurrence of various kinds of complications involving developmental disorders. In a prior study, we examined how a common marmoset's (Callithrix jacchus) psychosocial development was affected when it was reared under constant daylight from birth and then reared individually by humans nursing them under constant light (LL) during their juvenile development stages. The behaviors of these marmosets were compared with those of normal day-night cycle (LD) marmosets using a multivariate analysis based on principal component analysis (PCA). That study found that LL marmosets relatively elicited egg-like calls (Ecall) and side-to-side shakes of the upper body with rapid head rotation through adulthood frequently. Based on the PCA, these behaviors were interpreted as "alert" or "hyperactive" states. However, we did not clarify susceptible periods of the photic rhythm loss experience and the psychological development output. In this study we summarize the following studies in our model animal colonies involving 30 animals (11 female, 19 males) to further explore critical age states of inquiry about each social behavior profiling. We compared social behaviors of three age stages, juvenile, adolescent and young adult equivalent to one another in four LL experience conditions, LL (postnatal day (P) 0 to around 150), Middle (P60-149, 90 days), Late (P150-239, 90 days), and LD (no experience). In the most representative 1st and 2nd principal component scores, the shifting to higher frequency of alert behaviors developed at the adult stage in LL, Middle, then Late in turn. The no LL experience group, LD, generally featured higher frequency of local preference of high position compared to LL experience present groups, in adulthood. This limited model primate study might inspire different developmental age sensitive mechanisms of neuronal network to control socio-emotional functions by utilizing the multivariate visualization method, BOUQUET. This study could potentially contribute to nurturing educational designs for social developmental disorders.

Mini-atlas of the marmoset brain.

A mini-atlas of the brain is designed to help students and young researchers who are not familiar with neuroanatomy. In the mini-atlas, a limited number of important nuclei and fiber tracts are shown on a small number of brain sections from posterior end to the anterior end of the brain. The first mini-atlas was introduced for the rat brain (Watson et al., 2010). Here we present a mini-atlas of the common marmoset (Callithrix jaccus), which is one of representative experimental primates for modern neuroscience. We further discuss the differences of brain structures between rodents and primates.

Susceptible period of socio-emotional development affected by constant exposure to daylight.

As a diurnal experimental primate, the common marmoset (Callithrix jacchus) has recently contributed to numerous kinds of studies of neurobiological psychiatry as an essential pre-clinical model. The marmoset matures sexually within one or two years after birth. Thus, we can observe how the primate learns and develops psycho-cognitive functions through experiences in experimental environment for a much shorter period compared to that of humans. Longer daylight exposure may affect psychological development of children. In our research, we focus on raising marmosets under constant daylight from birth until various ages. In order to quantitatively evaluate the development of higher-ordered psychological functions, we designed a system of socio-behavioral tests and multivariate correlation analysis methods based on principal component analysis. With reference to the call and typical body movement expressed during a particular social context, we statistically inferred the emotional features of the subjects. In the current literature, we review our published results showing increased alert behaviors by constant light, and then, attempted to extend our additional analysis to seek age-dependent susceptibility to constant light. We then present the neurobiological mechanisms with reference to previous research reports. The current review suggests possible existence of a susceptible period earlier than three to five month-old in the environment-induced developmental disorder model, supposedly like attention deficit hyperactive disorders (ADHD) or oppositional defiant disorder (ODD).

Potential of a smartphone as a stress-free sensor of daily human behaviour.

Behaviour is one of the most powerful objective signals that connotes psychological functions regulated by neuronal network systems. This study searched for simple behaviours using smartphone sensors with three axes for measuring acceleration, angular speed and direction. We used quantitative analytic methodology of pattern recognition for work contexts, individual workers and seasonal effects in our own longitudinally recorded data. Our 13 laboratory members were involved in the care of common marmosets and domestic chicks, which lived in separate rooms. They attached a smartphone to their front waist-belts during feeding and cleaning in five care tasks. Behavioural characteristics such as speed, acceleration and azimuth, pitch, and roll angles were monitored. Afterwards, participants noted subjective scores of warmth sensation and work efficiency. The multivariate time series behavioral data were characterized by the subjective scores and environmental factors such as room temperature, season, and humidity, using the linear mixed model. In contrast to high-precision but stress-inducing sensors, the mobile sensors measuring daily behaviours allowed us to quantify the effects of the psychological states and environmental factors on the behavioural traits.

A cross-species socio-emotional behaviour development revealed by a multivariate analysis.

Recent progress in affective neuroscience and social neurobiology has been propelled by neuro-imaging technology and epigenetic approach in neurobiology of animal behaviour. However, quantitative measurements of socio-emotional development remains lacking, though sensory-motor development has been extensively studied in terms of digitised imaging analysis. Here, we developed a method for socio-emotional behaviour measurement that is based on the video recordings under well-defined social context using animal models with variously social sensory interaction during development. The behaviour features digitized from the video recordings were visualised in a multivariate statistic space using principal component analysis. The clustering of the behaviour parameters suggested the existence of species- and stage-specific as well as cross-species behaviour modules. These modules were used to characterise the behaviour of children with or without autism spectrum disorders (ASDs). We found that socio-emotional behaviour is highly dependent on social context and the cross-species behaviour modules may predict neurobiological basis of ASDs.

Peer attachment formation by systemic redox regulation with social training after a sensitive period.

Attachment formation is the most pivotal factor for humans and animals in the growth and development of social relationships. However, the developmental processes of attachment formation mediated by sensory-motor, emotional, and cognitive integration remain obscure. Here we developed an animal model to understand the types of social interactions that lead to peer-social attachment formation. We found that the social interaction in a sensitive period was essential to stabilise or overwrite the initially imprinted peer affiliation state and that synchronised behaviour with others based on common motivations could be a driver of peer social attachment formation. Furthermore, feeding experience with supplementation of ubiquinol conferred peer social attachment formation even after the sensitive period. Surprisingly, the experience of feeding beyond the cage window was also effective to reduce the required amount ubiquinol, suggesting that peri-personal space modulation may affect socio-emotional cognition and there by lead to attachment formation.

Familiarity perception call elicited under restricted sensory cues in peer-social interactions of the domestic chick.

Social cognitive mechanisms are central to understanding developmental abnormalities, such as autistic spectrum disorder. Peer relations besides parent-infant or pair-bonding interactions are pivotal social relationships that are especially well developed in humans. Cognition of familiarity forms the basis of peer socialization. Domestic chick (Gallus gallus) studies have contributed to our understanding of the developmental process in sensory-motor cognition but many processes remain unknown. In this report, we used chicks, as they are precocial birds, and we could therefore focus on peer interaction without having to consider parenting. The subject chick behavior towards familiar and unfamiliar reference peers was video-recorded, where the subject and the reference were separated by either an opaque or transparent wall. Spectrogram and behavior correlation analyses based on principal component analysis, revealed that chicks elicited an intermediate contact call and a morphologically different distress call, more frequently towards familiar versus unfamiliar chicks in acoustic only conditions. When both visual and acoustic cues were present, subject chicks exhibited approaching and floor pecking behavior, while eliciting joyful (pleasant) calls, irrespective of whether reference peers were familiar or unfamiliar. Our result showed that chicks recognized familiarity using acoustic cues and expressed cognition through modified distress calls. These finding suggests that peer affiliation may be established by acoustic recognition, independent of visual face recognition, and that eventually, both forms of recognition are integrated, with modulation of acoustic recognition.

[Development and neural basis of social behavior].

We have developed a multi variate analysis of social communication behavior which allows for discriminating the emotional state of an agent interacting with other agents (Bouquet method). Domestic chick or common marmoset was reared under socially isolated conditions, later tested for its development of communication behavior with peers by Bouquet, and compared with that of animals reared under grouping conditions. We found the existence of high sensitive period for social interaction, given less experience, developing less affiliated behavior. From chick model, a couple of neuronal difference was observed between two groups, amygdale core central cell size, MRI volumetric measure in mesolimbic area, and gene expression patter including brain type tryptophan hydroxylase in nucleus accumbens. The isolated chick behavior changed better to be socially affiliated by taking SSRI/SNRI or Ubiquinol (the reduced form of CoQ10) together with social interaction experience after the sensitive period. Finally, we could discriminate the behavior of Asperger syndrome children (n = 7) from that of the typically developed siblings (n = 6) during the clinical interview by applying Bouquet method.

Reading marmoset behavior 'semantics' under particular social context by multi-parameters correlation analysis.

Social interactions are a fundamental aspect of human and animal behavior. Although neuroimaging and other non-invasive methods have progressed recently, the neurobiology of social behavior requires the use of animal models. Here, we introduced a multi-behavior parameter integration method and applied it to female-male interaction of adult common marmosets (Callithrix jacchus). Based on the correlated parameters and meeting context, we found that the behavioral endpoints clustered in four distinct categories, which could be interpreted as active, freeze, alert, and affinity emotional states. The relevance of this interpretation was supported as the female behavior category change positively correlated with serum cortisol and progesterone levels after social interaction. Thus, our multi-behavior parameter integration method may be useful to evaluate social emotionality in animal models, as well as to quantify social behavior in human psychiatric disorders.

Internet-based atlas of the primate spinal cord.

In 2009, we reported an online brain atlas of the common marmoset (Callithrix jacchus) at http://marmoset-brain.org:2008. Here we report new digital images of the primate spinal cord sections added to the website. We prepared histological sections of every segment of the spinal cord of the common marmoset, rhesus monkey and Japanese monkey with various staining techniques. The sections were scanned with Carl Zeiss MIRAX SCAN at light microscopic resolution. Obtained digital data were processed and converted into multi-resolutionary images with Adobe Photoshop and Zoomify Design. These images of the primate spinal cords are now available on the web via the Internet.

Effects of constant daylight exposure during early development on marmoset psychosocial behavior.

Due to global industrialization, the light cycle is shifting to longer daytime. Mounting evidence indicates that social developmental disorders may correlate with longer periods of daytime in childhood. However, the exact mechanisms of this link remain unclear. To examine the impact of longer day-time on psychosocial development, we developed a novel non-human primate model, using the common marmoset (Callithrix jacchus) reared under constant daylight from birth. Marmosets were reared individually by human nursing under constant light (LL) during varying periods in juvenile development, and their behaviors were compared with those of normal day-night cycle (LD) marmosets by multivariate analysis based on principal component analysis (PCA). LL marmosets elicited egg-like calls (e-call) less in juvenile period, and displayed side-to-side shakes of the upper body with rapid head rotation through adulthood frequently. Based on the PCA, these behaviors were interpreted as 'alert' or 'hyperactive' states. Additionally, behavioral development of marmosets reared under constant dark (DD) was markedly different from both LD and LL marmosets, suggesting the fundamental importance of daylight-dependent neuronal and endocrine processes and entrainment by a constant 24-hour light/dark cycle on psychosocial behavior development.