Mechanisms for the Approach/Avoidance Decision Applied to Autism (original) (raw)

Social and non-social autism symptom and trait domains are genetically dissociable

2017

The core diagnostic criteria for autism comprise two symptom domains – social and communication difficulties, and unusually repetitive and restricted behaviour, interests and activities. There is some evidence to suggest that these two domains are dissociable, yet, this hypothesis has not been tested using molecular genetics. We test this using a GWAS of a non-social autistic trait, systemizing (N = 51,564), defined as the drive to analyse and build systems. We demonstrate that systemizing is heritable and genetically correlated with autism. In contrast, we do not identify significant genetic correlations between social autistic traits and systemizing. Supporting this, polygenic scores for systemizing are significantly positively associated with restricted and repetitive behaviour but not with social difficulties in autistic individuals. These findings strongly suggest that the two core domains of autism are genetically dissociable, and point at how to fractionate the genetics of au...

Parallel social information processing circuits are differentially impacted in autism

Parallel processing circuits are thought to dramatically expand the network capabilities of the nervous system. Magnocellular and parvocellular oxytocin neurons have been proposed to subserve two parallel streams of social information processing, which allow a single molecule to encode a diverse array of ethologically distinct behaviors, although to date direct evidence to support this hypothesis is lacking. Here we provide the first comprehensive characterization of magnocellular and parvocellular oxytocin neurons, validated across anatomical, projection target, electrophysiological, and transcriptional criteria. We next used novel multiple feature selection tools in Fmr1 KO mice to provide direct evidence that normal functioning of the parvocellular but not magnocellular oxytocin pathway is required for autism-relevant social reward behavior. Finally, we demonstrate that autism risk genes are uniquely enriched in parvocellular oxytocin neurons. Taken together these results provide...

Abnormal Social Behaviors And Dysfunction Of Autism-Related Genes Associated With Daily Agonistic Interactions In Mice

Background: The ability of people to communicate with each other is a necessary component of social behavior and the normal development of individuals who live in a community. An apparent decline in sociability may be the result of a negative social environment or the development of affective and neurological disorders, including autistic spectrum disorders. The behavior of these humans may be characterized by the deterioration of socialization, low communication, and repetitive and restricted behaviors. This study aimed to analyze changes in the social behaviors of male mice induced by daily agonistic interactions and investigate the involvement of genes, related with autistic spectrum disorders in the process of the impairment of social behaviors. Methods: Abnormal social behavior is induced by repeated experiences of aggression accompanied by wins (winners) or chronic social defeats (losers) in daily agonistic interactions in male mice. The collected brain regions (the midbrain r...

Neuronal correlates of asocial behavior in a BTBR T (+) Itpr3(tf)/J mouse model of autism.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized, in part, by an inability to adequately respond to social cues. Patients diagnosed with ASD are often devoid of empathy and impaired in understanding other people's emotional perspective. The neuronal correlates of this impairment are not fully understood. Replicating such a behavioral phenotype in a mouse model of autism would allow us insight into the neuronal background of the problem. Here we tested BTBR T(+)Itpr3(tf)/J (BTBR) and c57BL/6J (B6) mice in two behavioral paradigms: the Transfer of Emotional Information test and the Social Proximity test. In both tests BTBR mice displayed asocial behavior. We analyzed c-Fos protein expression in several brain regions after each of these tests, and found that, unlike B6 mice, BTBR mice react to a stressed cagemate exposure in the Transfer of Emotional Information test with no increase of c-Fos expression in either the prefrontal cortex or the amygdala. However, after Social Proximity exposure we observed a strong increase in c-Fos expression in the CA3 field of the hippocampus and two hypothalamic regions of BTBR brains. This response was accompanied by a strong activation of periaqueductal regions related to defensiveness, which suggests that BTBR mice find unavoidable social interaction highly aversive.