A brain structural connectivity biomarker for autism spectrum disorder diagnosis in early childhood.

Background: Autism spectrum disorder (ASD) is associated with altered brain development, but it is unclear which specific structural changes may serve as potential diagnostic markers, particularly in young children at the age when symptoms become fully established. Furthermore, such brain markers need to meet the requirements of precision medicine and be accurate in aiding diagnosis at an individual rather than only a group level. Objective: This study aimed to identify and model brain-wide differences in structural connectivity using diffusion tensor imaging (DTI) in young ASD and typically developing (TD) children. Methods: A discovery cohort including 93 ASD and 26 TD children and two independent validation cohorts including 12 ASD and 9 TD children from three different cities in China were included. Brain-wide (294 regions) structural connectivity was measured using DTI (fractional anisotropy, FA) together with symptom severity and cognitive development. A connection matrix was constructed for each child for comparisons between ASD and TD groups. Pattern classification was performed on the discovery dataset and the resulting model was tested on the two independent validation datasets. Results: Thirty-three structural connections showed increased FA in ASD compared to TD children and associated with both autistic symptom severity and impaired general cognitive development. The majority (29/33) involved the frontal lobe and comprised five different networks with functional relevance to default mode, motor control, social recognition, language and reward. Overall, classification achieved very high accuracy of 96.77% in the discovery dataset, and 91.67% and 88.89% in the two independent validation datasets. Conclusions: Identified structural connectivity differences primarily involving the frontal cortex can very accurately distinguish novel individual ASD from TD children and may therefore represent a robust early brain biomarker which can address the requirements of precision medicine.

Involvement of Opioid Peptides in the Analgesic Effect of Spinal Cord Stimulation in a Rat Model of Neuropathic Pain.

Spinal cord stimulation (SCS)-induced analgesia was characterized, and its underlying mechanisms were examined in a spared nerve injury model of neuropathic pain in rats. The analgesic effect of SCS with moderate mechanical hypersensitivity was increased with increasing stimulation intensity between the 20% and 80% motor thresholds. Various frequencies (2, 15, 50, 100, 10000 Hz, and 2/100 Hz dense-dispersed) of SCS were similarly effective. SCS-induced analgesia was maintained without tolerance within 24 h of continuous stimulation. SCS at 2 Hz significantly increased methionine enkephalin content in the cerebrospinal fluid. The analgesic effect of 2 Hz was abolished by µ or κ opioid receptor antagonist. The effect of 100 Hz was prevented by a κ antagonist, and that of 10 kHz was blocked by any of the µ, δ, or κ receptor antagonists, suggesting that the analgesic effect of SCS at different frequencies is mediated by different endorphins and opioid receptors.

The salience of competing nonsocial objects reduces gaze toward social stimuli, but not the eyes, more in typically developing than autistic boys.

Decreased attention to social information is considered an early emerging symptom of autism spectrum disorder (ASD), although the underlying causes remain controversial. Here we explored the impact of nonsocial object salience on reduced attention to social stimuli in male ASD compared with typically developing (TD) children. Correlations with blood concentrations of neuropeptides linked with social cognition were also investigated. Eye-tracking was performed in 102 preschool-aged boys (50 ASD, 52 TD) using a paradigm with social (faces) versus nonsocial (objects) stimuli presented in pairs in two conditions where nonsocial stimulus salience was varied. Basal oxytocin (OXT) and vasopressin concentrations were measured in blood. Compared with TD boys those with ASD viewed social stimuli less only when they were paired with low-salience nonsocial objects. Additionally, boys with ASD spent less time than TD ones viewing facial features, particularly the eyes. In TD boys, OXT concentrations and cognitive development scores were positively associated with time spent viewing the eye region, whereas for boys with ASD associations with time spent viewing faces were negative. Reduced gaze toward social stimuli in ASD relative to TD individuals may therefore be influenced by how salient the paired nonsocial objects are for the latter. On the other hand, reduced interest in the eyes of faces in boys with ASD is not influenced by how salient competing nonsocial stimuli are. Basal OXT concentrations and cognitive development scores are predictive of time spent viewing social stimuli in TD boys (eyes) and those with ASD (faces) but in the opposite direction. LAY SUMMARY: Children with autism exhibit reduced attention to social paired with nonsocial stimuli compared to typically developing children. Using eye-tracking we show this difference is due to typically developing rather than autistic boys being more influenced by how interesting competing nonsocial objects are. On the other hand, reduced time looking at the eyes in autistic relative to typically developing boys is unaffected by nonsocial object salience. Time spent viewing social stimuli is associated with cognitive development and blood levels of oxytocin.

Postnatal AVP treatments prevent social deficit in adolescence of valproic acid-induced rat autism model.

Studies have shown that arginine-vasopressin (AVP) is an important neuropeptide regulating social behaviors. The present work aimed to detect changes in the AVP numbers and level in a valproic acid (VPA)-induced rat model of autism and the underlying mechanism of its pathogenesis. Our results indicated that infants exposed to VPA showed obviously impaired communication and repetitive behaviors with reduced number of AVP-ir cells in paraventricular nucleus (PVN) and cerebrospinal fluid (CSF). The postnatal subcutaneous injection of AVP can alleviate social preference deficits and stereotyped behaviors, accompanied with the increase of the AVP concentrations in the CSF. We concluded that AVP system was involved in etiology of VPA-induced autism-like symptoms and postnatal AVP treatment rescued the behavioral deficits,which could be a promising treatment for autism.

Acupuncture and Related Techniques for Pain Relief and Treatment of Heroin Addiction: Mechanisms and Clinical Application.

A neurochemical hypothesis of acupuncture analgesia suggests that the pain relief effect of acupuncture is primarily due to activation of a central endorphin system. It has been shown that the primary afferent sensory fibers, a mesolymbic neural circuit, and a descending inhibitory pathway are critical in acupuncture analgesia. The therapeutic effects of electroacupuncture (EA) and related techniques, such as transcutaneous electroacupoint stimulation (TEAS), are frequency-dependent: different frequencies of EA activate different brain regions and release different neuropeptides. EA and TEAS have been used successfully to treat heroin addiction. Activation of endorphin gene expression and release by TEAS can explain the dramatic attenuation of withdrawal syndrome and prolongation of retention time during and after detoxification treatment in patients who are addicted to heroin. However, repeated EA at high intensity should be avoided because it can induce a gradual loss of the analgesic effect. Opioid-receptor desensitization occurs and is manifested as decreased ligand-binding affinity and second-messenger detachment. Repeated large doses of morphine induce morphine tolerance. Cross-tolerance between morphine and EA suggests similar underlying mechanisms. Recent studies have demonstrated that excessive activation of cholecystokinin (CCK), an antiopioid peptide, appears to be responsible. CCK-receptor subtype B (CCKBR) and opioid µ-receptor are co-expressed in the dorsal-horn neurons. Activation of CCKBR promotes formation of heteromerization of morphine-receptor and CCKBR. Interaction of the third transmembrane domain between the 2 receptors resulted in the reduced binding affinity of the opioid receptor.

Responses of Primary Afferent Fibers to Acupuncture-Like Peripheral Stimulation at Different Frequencies: Characterization by Single-Unit Recording in Rats.

The pain-relieving effect of acupuncture is known to involve primary afferent nerves (PANs) via their roles in signal transmission to the CNS. Using single-unit recording in rats, we characterized the generation and transmission of electrical signals in Aß and Aδ fibers induced by acupuncture-like stimuli. Acupuncture-like signals were elicited in PANs using three techniques: manual acupuncture (MAc), emulated acupuncture (EAc), and electro-acupuncture (EA)-like peripheral electrical stimulation (PES). The discharges evoked by MAc and EAc were mostly in a burst pattern with average intra-burst and inter-burst firing rates of 90 Hz and 2 Hz, respectively. The frequency of discharges in PANs was correlated with the frequency of PES. The highest discharge frequency was 246 Hz in Aß fibers and 180 Hz in Aδ fibers. Therefore, EA in a dense-disperse mode (at alternating frequency between 2 Hz and 15 Hz or between 2 Hz and 100 Hz) best mimics MAc. Frequencies of EA output >250 Hz appear to be obsolete for pain relief.

Altered Behaviors and Impaired Synaptic Function in a Novel Rat Model With a Complete Shank3 Deletion.

Mutations within the Shank3 gene, which encodes a key postsynaptic density (PSD) protein at glutamatergic synapses, contribute to the genetic etiology of defined autism spectrum disorders (ASDs), including Phelan-McDermid syndrome (PMS) and intellectual disabilities (ID). Although there are a series of genetic mouse models to study Shank3 gene in ASDs, there are few rat models with species-specific advantages. In this study, we established and characterized a novel rat model with a deletion spanning exons 11-21 of Shank3, leading to a complete loss of the major SHANK3 isoforms. Synaptic function and plasticity of Shank3-deficient rats were impaired detected by biochemical and electrophysiological analyses. Shank3-depleted rats showed impaired social memory but not impaired social interaction behaviors. In addition, impaired learning and memory, increased anxiety-like behavior, increased mechanical pain threshold and decreased thermal sensation were observed in Shank3-deficient rats. It is worth to note that Shank3-deficient rats had nearly normal levels of the endogenous social neurohormones oxytocin (OXT) and arginine-vasopressin (AVP). This new rat model will help to further investigate the etiology and assess potential therapeutic target and strategy for Shank3-related neurodevelopmental disorders.

Neonatal Oxytocin Treatment Ameliorates Autistic-Like Behaviors and Oxytocin Deficiency in Valproic Acid-Induced Rat Model of Autism.

Autism spectrum disorder (ASD) is characterized by impaired social communication and repetitive/stereotyped behaviors. The neuropeptide oxytocin (OXT) plays a critical role in regulating social behaviors in the central nervous system, as indicated in both human and animal studies. We hypothesized that central OXT deficit is one of causes of etiology of ASD, which may be responsible for the social impairments. To test our hypothesis, central OXT system was examined in valproic acid (VPA)-induced rat model of autism (VPA rat). Our results showed that adolescent VPA rats exhibited a lower level of OXT mRNA and fewer OXT-ir cells in the hypothalamus than control rats. Additionally, OXT concentration in cerebrospinal fluid (CSF) was reduced. The number of OXT-ir cells in the supraoptic nucleus (SON) of neonatal VPA rats was also lower. Autistic-like behaviors were observed in these animals as well. We found that an acute intranasal administration of exogenous OXT restored the social preference of adolescent VPA rats. Additionally, early postnatal OXT treatment had long-term effects ameliorating the social impairments and repetitive behaviors of VPA rats until adolescence. This was accompanied by an increase in OXT-ir cells. Taken together, we demonstrated there was central OXT deficiency in the VPA-induced rat model of autism, and showed evidence that early postnatal OXT treatment had a long-term therapeutic effect on the autistic-like behaviors in VPA rats.

Heteromerization of µ-opioid receptor and cholecystokinin B receptor through the third transmembrane domain of the µ-opioid receptor contributes to the anti-opioid effects of cholecystokinin octapeptide.

Activation of the cholecystokinin type B receptor (CCKBR) by cholecystokinin octapeptide (CCK-8) inhibits opioid analgesia. Chronic opiate treatment leads to an increase in the CCK-8 concentration and thus enhances the antagonism of CCK-8 against opioid analgesia; the underlying molecular mechanisms remain of great interest. In the present study, we validated the colocalization of the µ-opioid receptor (MOR) and CCKBR in pain signal transmission-related spinal cord dorsal horn and dorsal root ganglion neurons of rats. Co-immunoprecipitation (Co-IP) and fluorescence lifetime-imaging-microscopy-based fluorescence resonance energy transfer (FLIM-FRET) assays showed that MOR heteromerized with CCKBR directly in transfected HEK293 cells. Combined with MOR mutant construction, the third transmembrane domain of MOR (TM3MOR) was demonstrated to participate in heteromerization with CCKBR. Receptor ligand binding, ERK phosphorylation and cAMP assays showed that MOR heteromerization with CCKBR weakened the activity of MOR. A cell-penetrating interfering peptide consisting of TM3MOR and TAT (a transactivator of HIV-1) sequences from the N terminal to the C terminal disrupted the MOR-CCKBR interaction and restored the activity of MOR in transfected HEK293 cells. Furthermore, intrathecal application of the TM3MOR-TAT peptide alleviated CCK-8-injection-induced antagonism to morphine analgesia in rats. These results suggest a new molecular mechanism for CCK-8 antagonism to opioid analgesia in terms of G-protein-coupled receptor (GPCR) interaction through direct heteromerization. Our study may provide a potential strategy for pain management with opioid analgesics.

Chinese children with autism: A multiple chemical elements profile in erythrocytes.

Several lines of evidence suggested that abnormal levels of certain chemical elements may contribute to the development of autism spectrum disorders (ASD). The present work aimed to investigate the multiple chemical elements profile in the erythrocytes of autistic versus typically developing children (TDC) of China. Analyses were carried out to explore the possible association between levels of elements and the risk as well as the severity of ASD. Erythrocyte levels of 11 elements (32%) among 34 detected elements in autistic group were significantly different from those in the TDC group. To our knowledge, this is the first study which compared the levels of rare earth elements in erythrocytes between children with or without ASD. Five elements including Pb, Na, Ca, Sb, and La are associated with the Childhood Autism Rating Scale (CARS) total score. Also, a series of tendencies were found in this research which was believed to affect auditory response, taste, smell, and touch, as well as fear or nervousness. It can be concluded that Chinese autistic children suffer from multi-chemical element imbalances which involves a complex combination of genetic and environmental factors. The results showed a significant correlation between abnormal levels of several chemical elements and the severity of the autistic syndrome. LAY SUMMARY: It is suggested that abnormal levels of some chemical elements may contribute to the development of autism spectrum disorders (ASD). In this work, the impact of element imbalances on the risk and severity of ASD was investigated, focusing on the analysis of abnormal levels of the multi-chemical elements profile in erythrocytes compared with typically developing children. Furthermore, the results showed a significant correlation between abnormal levels of several chemical elements and the severity of the autistic syndrome. Autism Res 2018, 11: 834-845. © 2018 International Society for Autism Research, Wiley Periodicals, Inc.

Development of an Autism Subtyping Questionnaire Based on Social Behaviors.

Autism spectrum disorder can be differentiated into three subtypes (aloof, passive, and active-but-odd) based on social behaviors according to the Wing Subgroups Questionnaire (WSQ). However, the correlations between the scores on some individual items and the total score are poor. In the present study, we translated the WSQ into Chinese, modified it, validated it in autistic and typically-developing Chinese children, and renamed it the Beijing Autism Subtyping Questionnaire (BASQ). Our results demonstrated that the BASQ had improved validity and reliability, and differentiated autistic children into these three subtypes more precisely. We noted that the autistic symptoms tended to be severe in the aloof, moderate in the passive, and mild in the active-but-odd subtypes. The modified questionnaire may facilitate etiological studies and the selection of therapeutic regimes.

[A Preliminary Study on Effect of Transcutaneous Electrical Acupoint Stimulation for Children with Autism].

OBJECTIVE: To investigate the clinical efficacy of transcutaneous electrical acupoint stimulation (TEAS) in treating children with autism spectrum disorders. METHODS: Forty-one autistic children receiving rehabilitation training were randomized into TEAS (n=21) and control (n=20) groups. The control group only received rehabilitation training. The TEAS group received both rehabilitation training and TEAS treatment[2 Hz/15 Hz alternating frequencies through two pairs of skin electrodes placed at Hegu (LI 4)-Neiguan (PC 6) on unilateral side, and Zusanli (ST 36)-Sanyinjiao (SP 6) on the contralateral side]. The treatment was given 30 min per day for 12 weeks. The outcome assessment was quantified with a series of rating scales including Autism Behavior Checklist (ABC), Childhood Autism Rating Scale (CARS) and Parent Symptom Questionnaire (PSQ). RESULTS: (1) The TEAS group showed more significant improvement than the control group in ABC (P<0.01). 38.1% effective rate (8/21) was observed in the TEAS group compared to 5.0% (1/20) in the control group (P<0.05). The CARS scores of both groups were reduced (P<0.0001) after treatment. The TEAS group showed significantly lower score compared to the control group (P<0.0001). (2)There was a distinctly reduced PSQ score in both TEAS and control groups (P<0.001) after treatment.(3)TEAS intervention showed better effect in children under 6 years old with moderate or severe autistic symptoms. CONCLUSIONS: TEAS intervention can significantly improve the autistic symptoms.

The Role of the Oxytocin/Arginine Vasopressin System in Animal Models of Autism Spectrum Disorder.

The nonapeptides oxytocin (OXT) and arginine vasopressin (AVP) are two key mediators in regulating various aspects of mammalian social behaviours. There are several lines of evidence that genetic variants of the OXT/AVP system exist in autism spectrum disorder (ASD) and that this system is dysfunctional at least in some ASD entities. These findings have stimulated the interest to perform studies testing the potential therapeutic application of OXT/AVP in ASD. In this respect animal models are critical for investigating the pathophysiology and for compound screening leading to new therapeutic approaches. Based on findings in animal models that show alterations of the OXT/AVP system, it has been hypothesised that single- or multiple-dose administration or the stimulation of endogenous release can improve several social deficits. Here we comprehensively review the role of the OXT/AVP system in social recognition, social interaction and maternal behaviour in the light of different ASD animal models and patient studies. We further discuss implications for OXT/AVP-related pharmacological interventions to alleviate social deficits in ASD in the future.

Use of electroacupuncture and transcutaneous electrical acupoint stimulation in reproductive medicine: a group consensus.

With the rapid development of assisted reproductive technology, various reproductive disorders have been effectively addressed. Acupuncture-like therapies, including electroacupuncture (EA) and transcutaneous electrical acupoint stimulation (TEAS), become more popular world-wide. Increasing evidence has demonstrated that EA and TEAS are effective in treating gynecological disorders, especially infertility. This present paper describes how to select acupoints for the treatment of infertility from the view of theories of traditional Chinese medicine and how to determine critical parameters of electric pulses of EA/TEAS based on results from animal and clinical studies. It summarizes the principles of clinical application of EA/TEAS in treating various kinds of reproductive disorders, such as polycystic ovary syndrome (PCOS), pain induced by oocyte retrieval, diminished ovarian reserve, embryo transfer, and oligospermia/ asthenospermia. The possible underlying mechanisms mediating the therapeutic effects of EA/TEAS in reproductive medicine are also examined.

A Volumetric and Functional Connectivity MRI Study of Brain Arginine-Vasopressin Pathways in Autistic Children.

Dysfunction of brain-derived arginine-vasopressin (AVP) systems may be involved in the etiology of autism spectrum disorder (ASD). Certain regions such as the hypothalamus, amygdala, and hippocampus are known to contain either AVP neurons or terminals and may play an important role in regulating complex social behaviors. The present study was designed to investigate the concomitant changes in autistic behaviors, circulating AVP levels, and the structure and functional connectivity (FC) of specific brain regions in autistic children compared with typically developing children (TDC) aged from 3 to 5 years. The results showed: (1) children with ASD had a significantly increased volume in the left amygdala and left hippocampus, and a significantly decreased volume in the bilateral hypothalamus compared to TDC, and these were positively correlated with plasma AVP level. (2) Autistic children had a negative FC between the left amygdala and the bilateral supramarginal gyri compared to TDC. The degree of the negative FC between amygdala and supramarginal gyrus was associated with a higher score on the clinical autism behavior checklist. (3) The degree of negative FC between left amygdala and left supramarginal gyrus was associated with a lowering of the circulating AVP concentration in boys with ASD. (4) Autistic children showed a higher FC between left hippocampus and right subcortical area compared to TDC. (5) The circulating AVP was negatively correlated with the visual and listening response score of the childhood autism rating scale. These results strongly suggest that changes in structure and FC in brain regions containing AVP may be involved in the etiology of autism.

Genes Related to Oxytocin and Arginine-Vasopressin Pathways: Associations with Autism Spectrum Disorders.

Autism spectrum disorder (ASD) is a highly heritable neurodevelopmental disorders characterized by impaired social interactions, communication deficits, and repetitive behavior. Although the mechanisms underlying its etiology and manifestations are poorly understood, several lines of evidence from rodent and human studies suggest involvement of the evolutionarily highly-conserved oxytocin (OXT) and arginine-vasopressin (AVP), as these neuropeptides modulate various aspects of mammalian social behavior. As far as we know, there is no comprehensive review of the roles of the OXT and AVP systems in the development of ASD from the genetic aspect. In this review, we summarize the current knowledge regarding associations between ASD and single-nucleotide variants of the human OXT-AVP pathway genes OXT, AVP, AVP receptor 1a (AVPR1a), OXT receptor (OXTR), the oxytocinase/vasopressinase (LNPEP), and ADP-ribosyl cyclase (CD38).

[Transcutaneous electrical acupoint stimulation for asthenozoospermia].

OBJECTIVE: To study the effect of transcutaneous electrical acupoint stimulation (TEAS) in the treatment of asthenozoospermia. METHODS: We randomly divided 72 asthenozoospermia patients into a 2 Hz TEAS (n = 29), a 100 Hz TEAS (n = 20), and a blank control group (n = 23), those in the former two groups treated by 30 minutes of TEAS at 2 Hz and 100 Hz respectively, applied to the acupoints of bilateral Shenshu, left Zusanli, and Guanyuan, once a day for 60 days, while those in the blank control group left untreated. Using computer-assisted sperm analysis (CASA), we examined sperm concentration and motility as well as the percentages of grade a and grade a+b sperm in different groups of the patients. RESULTS: Compared with the baseline, 2 Hz TEAS significantly increased sperm motility (ï¼»12.76 ± 1.39ï¼½ vs ï¼»18.89 ± 2.46ï¼½%, P<0.05) and the percentage of grade a+b sperm ( ï¼»10.68 ± 1.22ï¼½ vs ï¼»16.32 ± 2.10ï¼½%, P<0.05) in the asthenozoospermic patients, while 100 Hz TEAS improved not only sperm motility (ï¼»12.32 ± 2.21ï¼½ vs ï¼»23.81 ± 3.42ï¼½%, P<0.01) and the percentage of grade a+b sperm (ï¼»10.45 ± 1.98ï¼½ vs ï¼»20.25 ± 2.82 ï¼½%, P<0.01), but also the percentage of grade a sperm (ï¼»6.44 ± 1.16ï¼½ vs ï¼»13.31 ± 2.30ï¼½%, P<0.05). Moreover, in comparison with the blank control group, 2 Hz TEAS also remarkably increased sperm motility (ï¼»9.57 ± 1.60ï¼½ vs ï¼»18.89 ± 2.46ï¼½%, P<0.05) and the percentage of grade a+b sperm (ï¼»7.81 ± 1.31ï¼½ vs ï¼»16.32 ± 2.10ï¼½%, P<0.05) in the asthenozoosperma patients, while 100 Hz TEAS improved not only sperm motility (ï¼»9.57 ± 1.60ï¼½ vs ï¼»23.81 ± 3.42ï¼½%, P<0.01) and the percentage of grade a+b sperm (ï¼»7.81 ± 1.31ï¼½ vs ï¼»20.25 ± 2.82ï¼½%, P<0.01) but also the percentage of grade a sperm (ï¼»4.87 ± 1.01ï¼½ vs ï¼»13.31 ± 2.30ï¼½%, P<0.01). Meanwhile, the rate of clinical effectiveness was significantly higher in the 100 Hz TEASthan in the blank control group either in intention-to-treat (ITT) analysis (100% vs 18.18%) orper-protocol (PP) analysis (90% vs 0%), and so was it than in the 2 Hz TEAS group based on the data of ITT (100% vs 33.33%). CONCLUSIONS: Both 2 Hz and 100 Hz TEAS are effective for the treatment of asthenozoospermia by improving sperm motility and vitality.

Effects of chronic restraint stress on social behaviors and the number of hypothalamic oxytocin neurons in male rats.

Oxytocin (OXT) and vasopressin (AVP) are considered to be related to mammalian social behavior and the regulation of stress responses. The present study investigated the effects of chronic homotypic restraint stress (CHRS) on social behaviors and anxiety, as well as its repercussions on OXT- and AVP-positive neurons in the paraventricular nucleus (PVN) and supraoptic nucleus (SON) nuclei in rat. Male Sprague-Dawley rats receiving CHRS were exposed to repeated restraint stress of 30min per day for 10days. Changes in social approach behaviors were evaluated with the three-chambered social approach task. Changes in anxiety-like behaviors were evaluated in the light-dark box test. The number of neurons expressing oxytocin and/or vasopressin in PVN and SON were examined by immunohistochemistry techniques. The results demonstrated that social approach was increased and anxiety was decreased following 10-day exposure to CHRS. Furthermore, the number of OXT-immunoreactive cells in PVN was increased significantly, whereas no change in SON was seen. The number of AVP immunoreactive cells either in PVN or SON was unaffected. The results of this study suggest that certain types of stress could be effective in the treatment of social dysfunction in persons with mental disorders such as autism, social anxiety disorder. The therapeutic effects may be mediated by changes in the function of OXT neurons in PVN.

Plasma Oxytocin and Arginine-Vasopressin Levels in Children with Autism Spectrum Disorder in China: Associations with Symptoms.

Autism spectrum disorder (ASD) is defined by impairments of social interaction and the presence of obsessive behaviors. The "twin" nonapeptides oxytocin (OXT) and arginine-vasopressin (AVP) are known to play regulatory roles in social behaviors. However, the plasma levels and behavioral relevance of OXT and AVP in children with ASD have seldom been investigated. It is also unknown whether their mothers have abnormal plasma peptide levels. Here, using well-established methods of neuropeptide measurement and a relatively large sample size, we determined the plasma levels of the two neuropeptides in 85 normal children, 84 children with ASD, and 31 mothers from each group of children. As expected, children with ASD had lower plasma OXT levels than gender-matched controls (P = 0.028). No such difference was found for plasma AVP concentrations. Correlation analysis showed that ASD children with higher plasma OXT concentrations tended to have less impairment of verbal communication (Rho = -0.22, P = 0.076), while those with higher plasma AVP levels tended to have lower levels of repetitive use of objects (Rho = -0.231, P = 0.079). Unlike the findings in children, maternal plasma OXT levels showed no group difference. However, plasma AVP levels in the mothers of ASD children tended to be lower than in the mothers of normal children (P = 0.072). In conclusion, our results suggest that the OXT system is dysregulated in children with ASD, and that OXT and AVP levels in plasma seem to be associated with specific autistic symptoms. The plasma levels of OXT or AVP in mothers and their ASD children did not seem to change in the same direction.