Biology subjects

Noppari, T.

Publications and source records attributed to Noppari, T..

3 recordsLinked to original sources

bioRxiv2025

Reduced inter-subject functional connectivity during movies in autism: Replicability across cross-national fMRI datasets

BackgroundAutism is a neurodevelopmental disorder characterized by repetitive behaviors and difficulties in social communication and interaction. Previous research has shown that these symptoms are linked to idiosyncratic behavioral and brain activity patterns while viewing natural social events in movies. This study aimed to investigate the replicability of brain activity idiosyncrasy in autistic individuals by comparing their inter-subject functional connectivity (ISFC) with that of neurotypical individuals. MethodsWe tested for ISFC differences between autistic and neurotypical groups using functional magnetic resonance imaging (fMRI) data from two independent datasets from Germany (Nneurotypical = 25, 7 Males, 18 Females; Nautism = 22, 12 Males, 10 Females) and Finland (Nneurotypical = 19, Nautism = 18; All males). Participants watched short movie stimuli, and pairwise ISFCs were computed across 273 brain regions. Group differences were evaluated using subject-wise permutation tests for each dataset. ResultsIn both datasets, the autistic group showed lower ISFCs compared to the neurotypical group, specifically between visual regions (e.g., occipital gyrus, cuneus) and parietal regions (e.g., superior and inferior parietal lobules), as well as between visual regions and frontal regions (e.g., inferior frontal gyrus, precentral gyrus). ISFC was higher in the Finnish autistic group in temporal regions associated with sound and speech processing. ConclusionsThe study confirmed the replicability of reduced ISFCs in autistic individuals during naturalistic movie-watching, especially between visual and parietal/frontal brain regions. These findings reinforce the utility of ISFC and naturalistic movie-watching paradigm in studying neural connectivity alterations in autism.

neuroscience↗

bioRxiv2024

Dopamine D2R and opioid MOR availability in autism spectrum disorder

Opioid and dopamine receptor systems are implicated in the pathoetiology of autism, but in vivo human brain imaging evidence for their role remains elusive. Here, we investigated regional type 2 dopamine and mu-opioid receptor (D2R and MOR, respectively) availabilities and regional interactions between the two neuromodulatory systems associated with autism spectrum disorder (ASD). In vivo positron emission tomography (PET) with radioligands [11C]raclopride (D2R) and [11C]carfentanil (MOR) was carried out in 16 adult males with high functioning ASD and 19 age and sex matched controls. Regional group differences in D2R and MOR receptor availabilities were tested with linear mixed models and associations between regional receptor availabilities were examined with correlations. There were no group differences in whole-brain voxel-wise analysis of DR2 but ROI analysis presented a lower overall mean D2R availability in striatum of the ASD versus control group. Post hoc regional analysis revealed reduced D2R availability in nucleus accumbens of the ASD group. The whole-brain voxel-wise analysis of MOR revealed precuneal up-regulation in the ASD group, but there was no overall group difference in the ROI analysis for MOR. MOR down-regulation was observed in the hippocampi of the ASD group in a post hoc analysis. Regional correlations between D2R and MOR availabilities were weaker in the ASD group versus control group in the amygdala and nucleus accumbens. These alterations may translate to disrupted modulation of social motivation and reward in ASD.

neuroscience↗

bioRxiv2021

Aberrant motor contagion of emotions in psychopathy and high-functioning autism

Psychopathy and autism are both associated with aberrant social interaction and communication, yet only psychopaths are markedly antisocial and violent. Here we compared the functional neural alterations underlying these two different phenotypes with distinct patterns of socioemotional difficulties. We studied 19 incarcerated male offenders with high psychopathic traits, 20 males with high-functioning autism and 19 age-matched healthy controls. All groups underwent functional magnetic resonance imaging while they viewed dynamic happy, angry and disgust facial expressions or listened to laughter and crying sounds. Psychopathy was associated with reduced somatomotor responses to almost all expressions, while subjects with autism demonstrated less marked and emotion-specific alterations in the somatomotor area. These data suggest that psychopathy and autism involve both common and distinct functional alterations in the brain networks involved in socioemotional processing.

neuroscience↗