Autism Spectrum Traits in the Typical Population Predict Structure and Function in the Posterior Superior Temporal Sulcus

Autism traits are commonly used as exclusionary criteria in studies of developmental prosopagnosia (DP). We investigated whether autism traits result in qualitatively different face processing in 43 DPs with high vs. low autism quotient (AQ) scores and 27 controls. Compared to controls, behavioral face recognition deficits were similar between the high and low AQ DP groups aside from worse emotion recognition in the high AQ DPs. Both DP groups showed reduced face selectivity in task-based fMRI, although higher AQ DPs showed decreased face selectivity in the posterior superior temporal sulcus. Resting-state fMRI showed similar face network connectivity between DP groups. This suggests that face processing is similar between the DP groups, with additional emotion processing deficits in higher AQ DPs.

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The Superficial White Matter in Autism and Its Role in Connectivity Anomalies and Symptom Severity

Cerebral Cortex ◽

10.1093/cercor/bhy321 ◽

2018 ◽

Vol 29 (10) ◽

pp. 4415-4425 ◽

Cited By ~ 10

Author(s):

Seok-Jun Hong ◽

Brian Hyung ◽

Casey Paquola ◽

Boris C Bernhardt

Keyword(s):

White Matter ◽

Functional Connectivity ◽

Symptom Severity ◽

Short Range ◽

Autism Spectrum ◽

Structure And Function ◽

Symptom Load ◽

Spectrum Disorders ◽

And Function ◽

Cortical Morphology

Abstract In autism spectrum disorders (ASDs), the majority of neuroimaging studies have focused on the analysis of cortical morphology. White matter changes remain less understood, particularly their association to cortical structure and function. Here, we focused on region that has gained only little attention in ASD neuroimaging: the superficial white matter (SWM) immediately beneath the cortical interface, a compartment playing a prominent role in corticogenesis that incorporates long- and short-range fibers implicated in corticocortical connectivity. Studying a multicentric dataset of ASD and neurotypical controls, we harnessed surface-based techniques to aggregate microstructural SWM diffusion features. Multivariate analysis revealed SWM anomalies in ASD compared with controls in medial parietal and temporoparietal regions. Effects were similar in children and adolescents/adults and consistent across sites. Although SWM anomalies were more confined when correcting for cortical thickness and surface area, findings were overall robust. Diffusion anomalies modulated functional connectivity reductions in ASD and related to symptom severity. Furthermore, mediation models indicated a link between SWM changes, functional connectivity, and symptom load. Analyses targeting the SWM offer a novel perspective on the interplay between structural and functional network perturbations in ASD, highlighting a potentially important neurobiological substrate contributing to its diverse behavioral phenotype.

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Molecular Mechanisms of Environmental Metal Neurotoxicity: A Focus on the Interactions of Metals with Synapse Structure and Function

Toxics ◽

10.3390/toxics9090198 ◽

2021 ◽

Vol 9 (9) ◽

pp. 198

Author(s):

Asuncion Carmona ◽

Stéphane Roudeau ◽

Richard Ortega

Keyword(s):

Environmental Exposure ◽

Molecular Mechanisms ◽

Neurological Diseases ◽

Autism Spectrum ◽

Structure And Function ◽

Synaptic Proteins ◽

Health Concern ◽

Synaptic Structure ◽

Cadmium Lead ◽

And Function

Environmental exposure to neurotoxic metals and metalloids such as arsenic, cadmium, lead, mercury, or manganese is a global health concern affecting millions of people worldwide. Depending on the period of exposure over a lifetime, environmental metals can alter neurodevelopment, neurobehavior, and cognition and cause neurodegeneration. There is increasing evidence linking environmental exposure to metal contaminants to the etiology of neurological diseases in early life (e.g., autism spectrum disorder) or late life (e.g., Alzheimer’s disease). The known main molecular mechanisms of metal-induced toxicity in cells are the generation of reactive oxygen species, the interaction with sulfhydryl chemical groups in proteins (e.g., cysteine), and the competition of toxic metals with binding sites of essential metals (e.g., Fe, Cu, Zn). In neurons, these molecular interactions can alter the functions of neurotransmitter receptors, the cytoskeleton and scaffolding synaptic proteins, thereby disrupting synaptic structure and function. Loss of synaptic connectivity may precede more drastic alterations such as neurodegeneration. In this article, we will review the molecular mechanisms of metal-induced synaptic neurotoxicity.

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Intermittent theta burst stimulation over the posterior superior temporal sulcus for children with autism spectrum disorder: A 4-week randomized blinded controlled trial followed by another 4-week open-label intervention

Autism ◽

10.1177/1362361321990534 ◽

2021 ◽

pp. 136236132199053

Author(s):

Hsing-Chang Ni ◽

Yi-Lung Chen ◽

Yi-Ping Chao ◽

Chen-Te Wu ◽

Yu-Yu Wu ◽

...

Keyword(s):

Autism Spectrum Disorder ◽

Social Cognitive ◽

Children With Autism ◽

Superior Temporal Sulcus ◽

Autism Spectrum ◽

Spectrum Disorder ◽

Theta Burst Stimulation ◽

Burst Stimulation ◽

Theta Burst ◽

Posterior Superior Temporal Sulcus

The posterior superior temporal sulcus is a potential therapeutic target of brain stimulation for autism spectrum disorder. We conducted a 4-week randomized, single-blind parallel sham-controlled trial, followed by additional 4-week open-label intervention to evaluate the feasibility and efficacy regarding intermittent theta burst stimulation over the bilateral posterior superior temporal sulcus in autism spectrum disorder. In total, 78 intellectually able children and adolescents were randomized to the active ( n = 40) and sham groups ( n = 38). During the first 4 weeks, the active group received two-session/week intermittent theta burst stimulation, whereas the sham group received the same number of sham stimulation. After unblinding, both groups received eight-session real stimulation over the additional 4 weeks. In total, 91% participants completed the protocol with mild and transitory side-effects. There was no significant group-by-time interaction for active versus sham group on clinical symptoms and social cognitive performances in the first 4 weeks. The within-group analysis revealed 8 weeks (including a 4-week blind trial and a 4-week open-label intervention) of intermittent theta burst stimulation achieved greater efficacy than 4-week interventions. Participants with higher intelligence, better social cognitive performances, alongside less attention-deficit hyperactivity disorder severity at baseline, were more likely to be responders. Our study demonstrated the feasibility of long-term intermittent theta burst stimulation over the posterior superior temporal sulcus in children and adolescents with autism spectrum disorder. However, the findings from the first 4-week blind trial do not support the therapeutic efficacy of intermittent theta burst stimulation over the posterior superior temporal sulcus on the clinical symptoms and cognitive performance of social impairment, given the current stimulation protocol. The exploratory analyses suggest that the therapeutic efficacy might be moderated by several individual characteristics and more intermittent theta burst stimulation sessions. Lay abstract Intermittent theta burst stimulation is a varied form of repetitive transcranial magnetic non-invasive brain stimulation technique used to treat several neurological and psychiatric disorders. Its feasibility and therapeutic effects on the bilateral posterior superior temporal sulcus in children with autism are unknown. We conducted a single-blind, sham-controlled parallel randomized clinical trial in a hitherto largest sample of intellectually able children with autism ( N = 78). Participants randomized to the active group received two-session/week intermittent theta burst stimulation for continuous 8 weeks. Those in the sham group received two-session/week sham stimulations in the first 4 weeks and then active intervention for the following 4 weeks after unblinding. First, we found that continuous 8-week intermittent theta burst stimulation on the bilateral posterior superior temporal sulcus in children with autism is safe and tolerable. Second, we found that 8-week intermittent theta burst stimulation produced greater therapeutic efficacy, although we did not find any significant effects of 4-week intermittent theta burst stimulation on core symptoms and social cognitive performances in autism. Further analysis revealed that participants with higher intelligence and better social cognitive performance, alongside less attention-deficit hyperactivity disorder severity at baseline, were more likely to be responders. This study identified that the factors contribute to responders and the results suggest that longer courses of non-invasive brain stimulation may be needed to produce therapeutic benefits in autism, with consideration of heterogeneous responses.

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Structure and function of neural networks in the retina

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100102213 ◽

1988 ◽

Vol 46 ◽

pp. 26-27

Author(s):

Peter Sterling

Keyword(s):

Ganglion Cells ◽

Three Dimensional ◽

Structure And Function ◽

Synaptic Connections ◽

Visual Axis ◽

One Dimensional ◽

Cat Retina ◽

Ultrathin Sections ◽

And Function ◽

Insight Into

The synaptic connections in cat retina that link photoreceptors to ganglion cells have been analyzed quantitatively. Our approach has been to prepare serial, ultrathin sections and photograph en montage at low magnification (˜2000X) in the electron microscope. Six series, 100-300 sections long, have been prepared over the last decade. They derive from different cats but always from the same region of retina, about one degree from the center of the visual axis. The material has been analyzed by reconstructing adjacent neurons in each array and then identifying systematically the synaptic connections between arrays. Most reconstructions were done manually by tracing the outlines of processes in successive sections onto acetate sheets aligned on a cartoonist's jig. The tracings were then digitized, stacked by computer, and printed with the hidden lines removed. The results have provided rather than the usual one-dimensional account of pathways, a three-dimensional account of circuits. From this has emerged insight into the functional architecture.

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Osseointegration interface of calcified bone and endosseous implants

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100130110 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1096-1097

Author(s):

K.E. Krizan ◽

J.E. Laffoon ◽

M.J. Buckley

Keyword(s):

Structure And Function ◽

Titanium Implants ◽

En Bloc ◽

Endosseous Implants ◽

Ultrastructural Studies ◽

The Past ◽

Cacodylate Buffer ◽

One Year ◽

And Function

With increase use of tissue-integrated prostheses in recent years it is a goal to understand what is happening at the interface between haversion bone and bulk metal. This study uses electron microscopy (EM) techniques to establish parameters for osseointegration (structure and function between bone and nonload-carrying implants) in an animal model. In the past the interface has been evaluated extensively with light microscopy methods. Today researchers are using the EM for ultrastructural studies of the bone tissue and implant responses to an in vivo environment. Under general anesthesia nine adult mongrel dogs received three Brånemark (Nobelpharma) 3.75 × 7 mm titanium implants surgical placed in their left zygomatic arch. After a one year healing period the animals were injected with a routine bone marker (oxytetracycline), euthanized and perfused via aortic cannulation with 3% glutaraldehyde in 0.1M cacodylate buffer pH 7.2. Implants were retrieved en bloc, harvest radiographs made (Fig. 1), and routinely embedded in plastic. Tissue and implants were cut into 300 micron thick wafers, longitudinally to the implant with an Isomet saw and diamond wafering blade [Beuhler] until the center of the implant was reached.

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Use of human autoantibodies and immunoelectron microscopy to study structure and function of the nucleolus and nuclear bodies

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100122939 ◽

1992 ◽

Vol 50 (1) ◽

pp. 506-507

Author(s):

Robert L. Ochs

Keyword(s):

Electron Microscopy ◽

Structure And Function ◽

Nuclear Bodies ◽

Nuclear Interior ◽

Coiled Bodies ◽

Interchromatin Granules ◽

And Function ◽

Conventional Electron Microscopy ◽

Perichromatin Granules ◽

Perichromatin Fibrils

By conventional electron microscopy, the formed elements of the nuclear interior include the nucleolus, chromatin, interchromatin granules, perichromatin granules, perichromatin fibrils, and various types of nuclear bodies (Figs. 1a-c). Of these structures, all have been reasonably well characterized structurally and functionally except for nuclear bodies. The most common types of nuclear bodies are simple nuclear bodies and coiled bodies (Figs. 1a,c). Since nuclear bodies are small in size (0.2-1.0 μm in diameter) and infrequent in number, they are often overlooked or simply not observed in any random thin section. The rat liver hepatocyte in Fig. 1b is a case in point. Historically, nuclear bodies are more prominent in hyperactive cells, they often occur in proximity to nucleoli (Fig. 1c), and sometimes they are observed to “bud off” from the nucleolar surface.

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Depletion and Reconstitution of Active E. Coli Ribosomes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100116826 ◽

1975 ◽

Vol 33 ◽

pp. 640-641

Author(s):

M. Boublik ◽

W. Hellmann ◽

F. Jenkins

Keyword(s):

Protein Biosynthesis ◽

Large Subunit ◽

High Resolution Electron Microscopy ◽

Small Subunit ◽

Structure And Function ◽

Biologically Active ◽

Biological Macromolecules ◽

E Coli ◽

Resolution Electron ◽

And Function

Correlations between structure and function of biological macromolecules have been studied intensively for many years, mostly by indirect methods. High resolution electron microscopy is a unique tool which can provide such information directly by comparing the conformation of biopolymers in their biologically active and inactive state. We have correlated the structure and function of ribosomes, ribonucleoprotein particles which are the site of protein biosynthesis. 70S E. coli ribosomes, used in this experiment, are composed of two subunits - large (50S) and small (30S). The large subunit consists of 34 proteins and two different ribonucleic acid molecules. The small subunit contains 21 proteins and one RNA molecule. All proteins (with the exception of L7 and L12) are present in one copy per ribosome.This study deals with the changes in the fine structure of E. coli ribosomes depleted of proteins L7 and L12. These proteins are unique in many aspects.

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