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Concept: Autism


Clinical chemistry tests for autism spectrum disorder (ASD) are currently unavailable. The aim of this study was to explore the diagnostic utility of proteotoxic biomarkers in plasma and urine, plasma protein glycation, oxidation, and nitration adducts, and related glycated, oxidized, and nitrated amino acids (free adducts), for the clinical diagnosis of ASD.

Concepts: Amino acid, Acid, Ammonia, Nitrogen, Autism, Asperger syndrome, Autism spectrum, Glycation


Autism spectrum disorders (ASD) are complex neurobiological disorders that impair social interactions and communication and lead to restricted, repetitive, and stereotyped patterns of behavior, interests, and activities. The causes of these disorders remain poorly understood, but gut microbiota, the 10(13) bacteria in the human intestines, have been implicated because children with ASD often suffer gastrointestinal (GI) problems that correlate with ASD severity. Several previous studies have reported abnormal gut bacteria in children with ASD. The gut microbiome-ASD connection has been tested in a mouse model of ASD, where the microbiome was mechanistically linked to abnormal metabolites and behavior. Similarly, a study of children with ASD found that oral non-absorbable antibiotic treatment improved GI and ASD symptoms, albeit temporarily. Here, a small open-label clinical trial evaluated the impact of Microbiota Transfer Therapy (MTT) on gut microbiota composition and GI and ASD symptoms of 18 ASD-diagnosed children.

Concepts: Bacteria, Gut flora, Digestive system, Escherichia coli, Autism, Pervasive developmental disorder, Asperger syndrome, Autism spectrum


Autism spectrum disorder (ASD) is defined by standardized criteria of qualitative impairments in social interaction, qualitative impairments in communication, and restricted and stereotyped patterns of behavior, interests, and activities. A significant number of children diagnosed with ASD suffer a loss of previously-acquired skills, which is suggestive of neurodegeneration or a type of progressive encephalopathy with an etiological pathogenic basis occurring after birth. To date, the etiology of ASD remains under debate, however, many studies suggest toxicity, especially from mercury (Hg), in individuals diagnosed with an ASD. The present study evaluated concerns about the toxic effects of organic-Hg exposure from Thimerosal (49.55% Hg by weight) in childhood vaccines by conducting a two-phased (hypothesis generating/hypothesis testing) study with documented exposure to varying levels of Thimerosal from vaccinations.

Concepts: Immune system, Vaccine, Vaccination, Greek loanwords, Autism, Mercury, Toxicity, Autism spectrum


Prior work has established that analytic thinking is associated with disbelief in God, whereas religious and spiritual beliefs have been positively linked to social and emotional cognition. However, social and emotional cognition can be subdivided into a number of distinct dimensions, and some work suggests that analytic thinking is in tension with some aspects of social-emotional cognition. This leaves open two questions. First, is belief linked to social and emotional cognition in general, or a specific dimension in particular? Second, does the negative relationship between belief and analytic thinking still hold after relationships with social and emotional cognition are taken into account? We report eight hypothesis-driven studies which examine these questions. These studies are guided by a theoretical model which focuses on the distinct social and emotional processing deficits associated with autism spectrum disorders (mentalizing) and psychopathy (moral concern). To our knowledge no other study has investigated both of these dimensions of social and emotion cognition alongside analytic thinking. We find that religious belief is robustly positively associated with moral concern (4 measures), and that at least part of the negative association between belief and analytic thinking (2 measures) can be explained by a negative correlation between moral concern and analytic thinking. Using nine different measures of mentalizing, we found no evidence of a relationship between mentalizing and religious or spiritual belief. These findings challenge the theoretical view that religious and spiritual beliefs are linked to the perception of agency, and suggest that gender differences in religious belief can be explained by differences in moral concern. These findings are consistent with the opposing domains hypothesis, according to which brain areas associated with moral concern and analytic thinking are in tension.

Concepts: Scientific method, Psychology, Belief, Faith, Autism, Mind, Religion, Spirituality


Autism spectrum disorder is a neurodevelopmental disorder of unknown aetiology. It is suggested to involve both genetic susceptibility and environmental factors including in the latter environmental toxins. Human exposure to the environmental toxin aluminium has been linked, if tentatively, to autism spectrum disorder. Herein we have used transversely heated graphite furnace atomic absorption spectrometry to measure, for the first time, the aluminium content of brain tissue from donors with a diagnosis of autism. We have also used an aluminium-selective fluor to identify aluminium in brain tissue using fluorescence microscopy. The aluminium content of brain tissue in autism was consistently high. The mean (standard deviation) aluminium content across all 5 individuals for each lobe were 3.82(5.42), 2.30(2.00), 2.79(4.05) and 3.82(5.17) μg/g dry wt. for the occipital, frontal, temporal and parietal lobes respectively. These are some of the highest values for aluminium in human brain tissue yet recorded and one has to question why, for example, the aluminium content of the occipital lobe of a 15year old boy would be 8.74 (11.59) μg/g dry wt.? Aluminium-selective fluorescence microscopy was used to identify aluminium in brain tissue in 10 donors. While aluminium was imaged associated with neurones it appeared to be present intracellularly in microglia-like cells and other inflammatory non-neuronal cells in the meninges, vasculature, grey and white matter. The pre-eminence of intracellular aluminium associated with non-neuronal cells was a standout observation in autism brain tissue and may offer clues as to both the origin of the brain aluminium as well as a putative role in autism spectrum disorder.

Concepts: Central nervous system, Nervous system, Brain, Human brain, Cerebrum, Skull, Autism, Frontal lobe


Internal action models (IAMs) are brain templates for sensory-motor coordination underlying diverse behaviors [1]. An emerging theory suggests that impaired IAMs are a common theme in autism spectrum disorder (ASD) [2-4]. However, whether impaired IAMs occur across sensory systems and how they relate to the major phenotype of ASD, namely impaired social communication [5], remains unclear. Olfaction relies on an IAM known as the sniff response, where sniff magnitude is automatically modulated to account for odor valence [6-12]. To test the failed IAM theory in olfaction, we precisely measured the non-verbal non-task-dependent sniff response concurrent with pleasant and unpleasant odors in 36 children-18 with ASD and 18 matched typically developing (TD) controls. We found that whereas TD children generated a typical adult-like sniff response within 305 ms of odor onset, ASD children had a profoundly altered sniff response, sniffing equally regardless of odor valance. This difference persisted despite equal reported odor perception and allowed for 81% correct ASD classification based on the sniff response alone (binomial, p < 0.001). Moreover, increasingly aberrant sniffing was associated with increasingly severe ASD (r = -0.75, p < 0.001), specifically with social (r = -0.72, p < 0.001), but not motor (r < -0.38, p > 0.18), impairment. These results uncover a novel ASD marker implying a mechanistic link between the underpinnings of olfaction and ASD and directly linking an impaired IAM with impaired social abilities.

Concepts: Autism, Pervasive developmental disorder, Sense, Olfaction, Asperger syndrome, Autism spectrum, Odor, Unpleasant odor


Synaesthesia is a neurodevelopmental condition in which a sensation in one modality triggers a perception in a second modality. Autism (shorthand for Autism Spectrum Conditions) is a neurodevelopmental condition involving social-communication disability alongside resistance to change and unusually narrow interests or activities. Whilst on the surface they appear distinct, they have been suggested to share common atypical neural connectivity.

Concepts: Nervous system, Autism, Pervasive developmental disorder, Asperger syndrome, Autism spectrum, PDD-NOS, Neural development, Neurodevelopmental disorder


Patients with anorexia may have elevated autistic traits. In this study, we tested test whether patients with anorexia nervosa (anorexia) have an elevated score on a dimensional measure of autistic traits, the Autism Spectrum Quotient (AQ), as well as on trait measures relevant to the autism spectrum: the Empathy Quotient (EQ), and the Systemizing Quotient (SQ).

Concepts: Autism, Pervasive developmental disorder, Asperger syndrome, Autism spectrum, PDD-NOS, Topological space


Prospective studies of infants at risk for autism spectrum disorder have provided important clues about the early behavioural symptoms of autism spectrum disorder. Diagnosis of autism spectrum disorder, however, is not currently made until at least 18 months of age. There is substantially less research on potential brain-based differences in the period between 6 and 12 months of age. Our objective in the current study was to use magnetic resonance imaging to identify any consistently observable brain anomalies in 6-9 month old infants who would later develop autism spectrum disorder. We conducted a prospective infant sibling study with longitudinal magnetic resonance imaging scans at three time points (6-9, 12-15, and 18-24 months of age), in conjunction with intensive behavioural assessments. Fifty-five infants (33 ‘high-risk’ infants having an older sibling with autism spectrum disorder and 22 ‘low-risk’ infants having no relatives with autism spectrum disorder) were imaged at 6-9 months; 43 of these (27 high-risk and 16 low-risk) were imaged at 12-15 months; and 42 (26 high-risk and 16 low-risk) were imaged again at 18-24 months. Infants were classified as meeting criteria for autism spectrum disorder, other developmental delays, or typical development at 24 months or later (mean age at outcome: 32.5 months). Compared with the other two groups, infants who developed autism spectrum disorder (n = 10) had significantly greater extra-axial fluid at 6-9 months, which persisted and remained elevated at 12-15 and 18-24 months. Extra-axial fluid is characterized by excessive cerebrospinal fluid in the subarachnoid space, particularly over the frontal lobes. The amount of extra-axial fluid detected as early as 6 months was predictive of more severe autism spectrum disorder symptoms at the time of outcome. Infants who developed autism spectrum disorder also had significantly larger total cerebral volumes at both 12-15 and 18-24 months of age. This is the first magnetic resonance imaging study to prospectively evaluate brain growth trajectories from infancy in children who develop autism spectrum disorder. The presence of excessive extra-axial fluid detected as early as 6 months and the lack of resolution by 24 months is a hitherto unreported brain anomaly in infants who later develop autism spectrum disorder. This is also the first magnetic resonance imaging evidence of brain enlargement in autism before age 2. These findings raise the potential for the use of structural magnetic resonance imaging to aid in the early detection of children at risk for autism spectrum disorder or other neurodevelopmental disorders.

Concepts: Brain, Nuclear magnetic resonance, Magnetic resonance imaging, Autism, Cerebrospinal fluid, Autism spectrum, Meninges, Subarachnoid space


Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder. Some anecdotal reports suggest that ASD is related to exposure to ethyl mercury, in the form of the vaccine preservative, thimerosal, and/or receiving the measles, mumps, rubella (MMR) vaccine. Using infant rhesus macaques receiving thimerosal-containing vaccines (TCVs) following the recommended pediatric vaccine schedules from the 1990s and 2008, we examined behavior, and neuropathology in three brain regions found to exhibit neuropathology in postmortem ASD brains. No neuronal cellular or protein changes in the cerebellum, hippocampus, or amygdala were observed in animals following the 1990s or 2008 vaccine schedules. Analysis of social behavior in juvenile animals indicated that there were no significant differences in negative behaviors between animals in the control and experimental groups. These data indicate that administration of TCVs and/or the MMR vaccine to rhesus macaques does not result in neuropathological abnormalities, or aberrant behaviors, like those observed in ASD.

Concepts: Brain, Vaccine, Autism, Pediatrics, MMR vaccine, Measles, Rubella, Mumps