Excessive Sensory Stimulation during Development Alters Neural Plasticity and Vulnerability to Cocaine in Mice

Excessive audio-visual stimulation leads to impaired social behaviour with an effect on amygdala: Early life excessive exposure to digital devices in male rats

Today, the effect of extreme early-life exposure to digital devices is suggested as a risk factor for neurodevelopmental disorders. However, the multitude of factors that influence brain development with subsequent behavioural abnormalities have not been fully elucidated. Herein, we simulated extreme early-life exposure to digital devices in rats by audio and visual stimulation and investigated its effects on autism-related behaviours and brain structural alteration. Male rat pups were exposed to excessive audio-visual stimulation (EAVS) from PND (post-natal day) 12 to PND 35, with and without maternal separation (MS). Autism-related behaviours including abnormal sociability, stereotype behaviours, anxiety and locomotor dysfunction were tested at PND 42. Brain structural alternation was examined by considering the amygdala, mPFC (medial prefrontal cortex) and hippocampal regions while performing 3D quantitative stereological analysis. We found that EAVS led to social behaviour deficit and higher locomotion in rats, which were associated with increases in the number of neurons and volume of the amygdala. We also showed that MS did not exaggerate the effect of extreme sensory stimulation on behaviour and the structure of the brain. This study proposed EAVS in rats as an animal model of early exposure to digital devices for investigating possible neurobiological alternations underlying autistic-like behaviours with an emphasis on the amygdala area.

Audiovisual overstimulation in childhood and adolescence promotes hyperactive behaviour in adult mice

There is a discussion about the impact of technological development on behavioural aspects, a nuance that the present study aimed to assess. p21, p26 and p36 mice were subjected to audio (70 db) and visual stimulation (flashing lights) for 2 or 6 h per day until p64. Naive animals were included. From p74 onwards, the animals were subjected to tests to assess their locomotion, depression, anxiety, aggressiveness, and nociception behaviours. Weight assessment was also performed. The animals that received stimulation for 2 h a day since p21 showed a decrease in rearing and grooming behaviour in the open field test, as well as in the mechanical orofacial sensitivity. Animals that received stimulation for 6 h daily since p21 showed increased locomotor activity in the open field test. Animals that received stimulation for 2 h a day since p26 showed an increase in locomotor activity and a decrease in grooming behaviour in the open field test, in addition to a reduction in the number of entries in the closed arm of the elevated plus maze. Animals stimulated from p26 for 6 h daily increased the reaction time to the thermal stimulus. Animals that received stimulation for 2 h daily since p36 showed an increase in locomotor activity and a decrease in grooming behaviour in the open field test. Taken together, these findings suggest that audiovisual overstimulation during critical periods of brain development may have adverse effects compatible with hyperactivity in adulthood.

How early media exposure may affect cognitive function: A review of results from observations in humans and experiments in mice

Attention deficit hyperactivity disorder (ADHD) is now among the most commonly diagnosed chronic psychological dysfunctions of childhood. By varying estimates, it has increased by 30% in the past 20 years. Environmental factors that might explain this increase have been explored. One such factor may be audiovisual media exposure during early childhood. Observational studies in humans have linked exposure to fast-paced television in the first 3 years of life with subsequent attentional deficits in later childhood. Although longitudinal and well controlled, the observational nature of these studies precludes definitive conclusions regarding a causal relationship. As experimental studies in humans are neither ethical nor practical, mouse models of excessive sensory stimulation (ESS) during childhood, akin to the enrichment studies that have previously shown benefits of stimulation in rodents, have been developed. Experimental studies using this model have corroborated that ESS leads to cognitive and behavioral deficits, some of which may be potentially detrimental. Given the ubiquity of media during childhood, these findings in humansand rodents perhaps have important implications for public health.

Internet and Video Game Addictions: Diagnosis, Epidemiology, and Neurobiology

In the past 2 decades, there has been substantial increase in availability and use of digital technologies, including the Internet, computer games, smart phones, and social media. Behavioral addiction to use of technologies spawned a body of related research. The recent inclusion of Internet gaming disorder as a condition for further study in the DSM-V invigorated a new wave of researchers, thereby expanding our understanding of these conditions. This article reviews current research, theory, and practice regarding the diagnosis, epidemiology, and neurobiology of Internet and video game addictions.