Electro-acupuncture improves the social interaction behavior of rats

Under or Absent Reporting of Light Stimuli in Testing of Anxiety-Like Behaviors in Rodents: The Need for Standardization

Behavioral neuroscience tests such as the Light/Dark Test, the Open Field Test, the Elevated Plus Maze Test, and the Three Chamber Social Interaction Test have become both essential and widely used behavioral tests for transgenic and pre-clinical models for drug screening and testing. However, as fast as the field has evolved and the contemporaneous involvement of technology, little assessment of the literature has been done to ensure that these behavioral neuroscience tests that are crucial to pre-clinical testing have well-controlled ethological motivation by the use of lighting (i.e., Lux). In the present review paper, N = 420 manuscripts were examined from 2015 to 2019 as a sample set (i.e., n = ~20–22 publications per year) and it was found that only a meager n = 50 publications (i.e., 11.9% of the publications sampled) met the criteria for proper anxiogenic and anxiolytic Lux reported. These findings illustrate a serious concern that behavioral neuroscience papers are not being vetted properly at the journal review level and are being released into the literature and public domain making it difficult to assess the quality of the science being reported. This creates a real need for standardizing the use of Lux in all publications on behavioral neuroscience techniques within the field to ensure that contributions are meaningful, avoid unnecessary duplication, and ultimately would serve to create a more efficient process within the pre-clinical screening/testing for drugs that serve as anxiolytic compounds that would prove more useful than what prior decades of work have produced. It is suggested that improving the standardization of the use and reporting of Lux in behavioral neuroscience tests and the standardization of peer-review processes overseeing the proper documentation of these methodological approaches in manuscripts could serve to advance pre-clinical testing for effective anxiolytic drugs. This report serves to highlight this concern and proposes strategies to proactively remedy them as the field moves forward for decades to come.

Effect of Early Swimming on the Behavior and Striatal Transcriptome of the Shank3 Knockout Rat Model of Autism

BACKGROUND

Autism spectrum disorder (ASD) is a developmental disorder characterized by social behavior deficits and stereotyped behaviors in childhood that lacks satisfactory medical intervention. Early swimming intervention is a noninvasive method combining enriched environment and exercise, which has been proven to improve brain development in young children and to treat neurodevelopmental diseases.

METHODS

In this study, we tested the autism-like behavior of rats with deletions in exons 11-21 of the Shank3 gene and evaluated the effect of early swimming intervention (from postnatal day 8 to 60) on the behavior of this animal model of autism. In addition, the transcriptomes of the striatal tissues of wild-type, Shank3 knockout and Shank3 knockout swimming groups rats were analyzed.

RESULTS

Shank3 knockout rats exhibit core symptoms of autism, and early swimming improved the social and stereotyped behaviors in this autism rat model. Transcriptomics results revealed that compared to the wild-type group, 291 differentially expressed genes (DEGs) were identified in the striatum of the Shank3 knockout group. Compared to Shank3 knockout group, 534 DEGs were identified in the striatum of Shank3 knockout swimming group. The DEGs annotated by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway shows that the impacts of Shank3 deletion were primarily reflected in synaptic structure, development, morphology, receptor function and signaling, and swimming primarily changed the terms related to the synapses in the striatum of Shank3 knockout rats, including the morphology, structure, composition, development and regulation of synapses.

CONCLUSION

Early swimming intervention can ameliorate behavioral abnormalities caused by Shank3 knockout, by a mechanism that may involve the process of striatal synaptic development and should be further investigated.

Electroacupuncture improves repeated social defeat stress-elicited social avoidance and anxiety-like behaviors by reducing Lipocalin-2 in the hippocampus

Background

Post-traumatic stress disorder (PTSD) is a trauma-related disorder that is associated with pro-inflammatory activation and neurobiological impairments in the brain and leads to a series of affective-like behaviors. Electroacupuncture (EA) has been proposed as a clinically useful therapy for several brain diseases. However, the potential role of EA treatment in PTSD and its molecular and cellular mechanisms has rarely been investigated.

Methods

We used an established preclinical social defeat stress mouse model to study whether EA treatment modulates PTSD-like symptoms and understand its underlying mechanisms. To this end, male C57BL/6 mice were subjected to repeated social defeat stress (RSDS) for 6 consecutive days to induce symptoms of PTSD and treated with EA at Baihui (GV 20) and Dazhui (GV 14) acupoints.

Results

The stimulation of EA, but not needle insertion at Baihui (GV 20) and Dazhui (GV 14) acupoints effectively improved PTSD-like behaviors such as, social avoidance and anxiety-like behaviors. However, EA stimulation at the bilateral Tianzong (SI11) acupoints did not affect the PTSD-like behaviors obtained by RSDS. EA stimulation also markedly inhibited astrocyte activation in both the dorsal and ventral hippocampi of RSDS-treated mice. Using next-generation sequencing analysis, our results showed that EA stimulation attenuated RSDS-enhanced lipocalin 2 expression in the hippocampus. Importantly, using double-staining immunofluorescence, we observed that the increased lipocalin 2 expression in astrocytes by RSDS was also reduced by EA stimulation. In addition, intracerebroventricular injection of mouse recombinant lipocalin 2 protein in the lateral ventricles provoked social avoidance, anxiety-like behaviors, and the activation of astrocytes in the hippocampus. Interestingly, the overexpression of lipocalin 2 in the brain also altered the expression of stress-related genes, including monoamine oxidase A, monoamine oxidase B, mineralocorticoid receptor, and glucocorticoid receptor in the hippocampus.

Conclusions

This study suggests that the treatment of EA at Baihui (GV 20) and Dazhui (GV 14) acupoints improves RSDS-induced social avoidance, anxiety-like behaviors, astrocyte activation, and lipocalin 2 expression. Furthermore, our findings also indicate that lipocalin 2 expression in the brain may be an important biomarker for the development of PTSD-related symptoms.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13041-021-00860-0.

Oxytocin in the anterior cingulate cortex attenuates neuropathic pain and emotional anxiety by inhibiting presynaptic long-term potentiation

Oxytocin is a well-known neurohypophysial hormone that plays an important role in behavioral anxiety and nociception. Two major forms of long-term potentiation, presynaptic LTP (pre-LTP) and postsynaptic LTP (post-LTP), have been characterized in the anterior cingulate cortex (ACC). Both pre-LTP and post-LTP contribute to chronic-pain-related anxiety and behavioral sensitization. The roles of oxytocin in the ACC have not been studied. Here, we find that microinjections of oxytocin into the ACC attenuate nociceptive responses and anxiety-like behavioral responses in animals with neuropathic pain. Application of oxytocin selectively blocks the maintenance of pre-LTP but not post-LTP. In addition, oxytocin enhances inhibitory transmission and excites ACC interneurons. Similar results are obtained by using selective optical stimulation of oxytocin-containing projecting terminals in the ACC in animals with neuropathic pain. Our results demonstrate that oxytocin acts on central synapses and reduces chronic-pain-induced anxiety by reducing pre-LTP.

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 oxytocinergic system: The promising treatment for autism

Autism spectrum disorder (ASD) is a group of heterogeneous neurodevelopmental disorders characterized by impairments activities without efficient pharmacological therapies in social interaction, speech and stereotypic patterns. Clinical studies have shown the efficacy of acupuncture as an alternative therapy for autism. The effectiveness of acupuncture as an alternative treatment for autism has been demonstrated through clinical trials. However, the molecular mechanisms that underlie these effects remain unclear. Due to its profound pro-social, anxiolytic, stress management effects, and its potential use for the treatment of psychiatric disorders associated with altered socioemotional competence, oxytocin (OT) released from the hypothalamus has attracted considerable interest. In the past decade, a number of clinical and animal studies have shown that OT administration effectively reduces core symptoms of ASD, especially social behavior deficits. Recently, the endocannabinoid system has emerged as a promising target for the treatment of autism. OT was found to facilitate the endocannabinoid-mediated social reward processes in the nucleus accumbens of the mouse brain. Furthermore, serotonin and dopamine are involved in the reward response mediated by OT. In view of these findings, we conclude that acupuncture may produce therapeutic effects on autism by triggering the hypothalamic oxytocin system, which in turn activates the release of neurotransmitters such as endocannabinoids, dopamine and serotonin. This would be a valuable guide for further research on the mechanism of treatment of autism with acupuncture.

Transcutaneous Electrical Acupoint Stimulation in Early Life Changes Synaptic Plasticity and Improves Symptoms in a Valproic Acid-Induced Rat Model of Autism

Autism spectrum disorder (ASD) is a developmental disorder characterized by social behavior deficit in childhood without satisfactory medical intervention. Transcutaneous electrical acupoint stimulation (TEAS) is a noninvasive technique derived from acupuncture and has been shown to have similar therapeutic effects in many diseases. Valproic acid- (VPA-) induced ASD is a known model of ASD in rats. The therapeutic efficacy of TEAS was evaluated in the VPA model of ASD in the present study. The offspring of a VPA-treated rat received TEAS in the early life stage followed by a series of examinations conducted in their adolescence. The results show that following TEAS treatment in early life, the social and cognitive ability in adolescence of the offspring of a VPA rat were significantly improved. In addition, the abnormal pain threshold was significantly corrected. Additional studies demonstrated that the dendritic spine density of the primary sensory cortex was decreased with Golgi staining. Results of the transcriptomic study showed that expression of some transcription factors such as the neurotrophic factor were downregulated in the hypothalamus of the VPA model of ASD. The reduced gene expression was reversed following TEAS. These results suggest that TEAS in the early life stage may mitigate disorders of social and recognition ability and normalize the pain threshold of the ASD rat model. The mechanism involved may be related to improvement of synaptic plasticity.

Disrupting the endocannabinoid system in early adolescence negatively impacts sociability

Animal models suggest that the endocannabinoid system (eCS) helps regulate various aspects of social behavior, including play behavior and social reward, during adolescence. Properly tuned endocannabinoid signaling may be a critical developmental component in the emergence of normal adult sociability. In the current experiment, we attempted to pharmacologically disrupt endocannabinoid tone during early adolescence, and then measure the behavioral effects at two subsequent time points. 36 male and 36 female Long Evans rats received daily injections of one of three treatments between post-natal day (PND) 25-39: 1) vehicle treatment, 2) 0.4 mg/kg CP55,940 (a potent CB1/CB2 receptor agonist), or 3) 0.5 mg/kg AM251 (a CB1 receptor antagonist/inverse agonist). Both soon after treatment (PND 40-44) and several weeks later (PND 66-70), subjects were tested in an elevated plus maze (EPM) for anxiety and in a three-chambered apparatus for sociability. For the latter test, the number of entries into each chamber and the amount of time spent investigating each target were measured. Analyses revealed significant main effects of both sex and age on sociability: males expressed greater sociability compared to females, and sociability was higher in adolescence than adulthood. Most importantly, drug treatment (both CP55,940 and AM251) attenuated sociability in adolescence without having a significant effect on anxiety in the EPM. However, this effect did not persist into adulthood. These results indicate that pharmacological disruption of endocannabinoid tone - through either chronic agonism or antagonism of cannabinoid receptors - during early adolescence has a detrimental effect on sociability. This effect may be caused by transient, compensatory alterations in the eCS.

A randomized placebo-controlled pilot trial shows that intranasal vasopressin improves social deficits in children with autism

The social impairments of autism spectrum disorder (ASD) have a major impact on quality of life, yet there are no medications that effectively treat these core social behavior deficits. Preclinical research suggests that arginine vasopressin (AVP), a neuropeptide involved in promoting mammalian social behaviors, may be a possible treatment for ASD. Using a double-blind, randomized, placebo-controlled, parallel study design, we tested the efficacy and tolerability of a 4-week intranasal AVP daily treatment in 30 children with ASD. AVP-treated participants aged 6 to 9.5 years received the maximum daily target dose of 24 International Units (IU); participants aged 9.6 to 12.9 years received the maximum daily target dose of 32 IU. Intranasal AVP treatment compared to placebo enhanced social abilities as assessed by change from baseline in this phase 2 trial's primary outcome measure, the Social Responsiveness Scale, 2nd Edition total score (SRS-2 T score; F _1,20 = 9.853; P = 0.0052; η_p ² = 33.0%; Cohen's d = 1.40). AVP treatment also diminished anxiety symptoms and some repetitive behaviors. Most of these findings were more pronounced when we accounted for pretreatment AVP concentrations in blood. AVP was well tolerated with minimal side effects. No AVP-treated participants dropped out of the trial, and there were no differences in the rate of adverse events reported between treatment conditions. Last, no changes from baseline were observed in vital signs, electrocardiogram tracings, height and body weight, or clinical chemistry measurements after 4 weeks of AVP treatment. These preliminary findings suggest that AVP has potential for treating social impairments in children with ASD.

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.

Laser Acupuncture Exerts Neuroprotective Effects via Regulation of Creb, Bdnf, Bcl-2, and Bax Gene Expressions in the Hippocampus

Acupuncture has a positive effect on cognitive deficits. However, the effects of laser acupuncture (LA) on cognitive function and its mechanisms of action are unclear. The present study aimed to evaluate the effects of LA on middle cerebral artery occlusion- (MCAO-) induced cognitive impairment and its mechanisms of action. Transient focal cerebral ischemia was modeled in adult Sprague-Dawley rats by MCAO. After LA or manual-acupuncture (MA) treatment at the GV20 and HT7 for 2 weeks, hippocampal-dependent memory was evaluated using the Morris water maze (MWM) test. The hippocampus was dissected to analyze choline acetyltransferase (ChAT) immunoreactivity and Creb, Bdnf, Bcl-2, and Bax gene expressions. MWM test demonstrated a significant improvement in hippocampal-dependent memory in the MCAO rats after LA treatment. LA treatment significantly reversed the postischemic decrease in ChAT immunoreactivity in the hippocampal CA1 region. LA treatment significantly normalized gene expression in the hippocampus which had been altered by MCAO, especially upregulating gene expression of Creb, Bdnf, and Bcl-2 and downregulating gene expression of Bax. This study suggests that LA treatment could improve cognitive impairment in MCAO rats to enhance the cholinergic system in the hippocampal CA1 region and to exert a neuroprotective effect by regulating Creb, Bdnf, Bcl-2, and Bax gene expressions.

Acupuncture and Acupressure in Labor

Acupuncture and acupressure, 2 modalities of Traditional Chinese Medicine, are based on reducing pain and symptoms of disease through balancing yin and yang. Acupuncture and acupressure have been used in China for reduction of labor pain, labor augmentation, and other intrapartum indications for more than 2 millennia. This article presents a review of the current literature that has addressed the effects of acupuncture and acupressure on intrapartum events. Studies of acupuncture have demonstrated that acupuncture may reduce labor pain, the use of pharmacologic agents, the use of forceps and vacuum-assisted births, and the length of labor. Studies that examined the effect of acupuncture on labor that is induced or augmented for premature rupture of membranes have found that acupuncture may increase the degree of cervical ripening but does not reduce the amount of oxytocin or epidural analgesia administration, nor does it shorten length of induced labor. Acupressure may reduce labor pain and labor duration, but acupressure has not been found to increase cervical ripening or induce labor. There are insufficient studies about acupuncture and acupressure and their effects on labor at this time, and there is need for further research. Areas of uncertainty include efficacy, optimal point selection, best techniques, and length of time for point stimulation.

Insomnia: can acupuncture help?

Insomnia is the forgotten partner to many medical problems, not least chronic pain where interference with sleep is a common complaint. However, the relationship is complex: lack of sleep can exacerbate pain through increase in proinflammatory cytokine production. Acupuncture is observed clinically to improve sleeping in chronic pain patients, but reviews are unable firmly to recommend acupuncture for insomnia as many trials are methodologically inadequate, despite most being acupuncture positive. However, there is strong evidence for relief in several chronic pain problems and improvement in these is likely also to restore normal sleeping. So, as the safety profile of acupuncture is excellent, it seems reasonable to utilize acupuncture in a nonpharmacological approach to combating insomnia, despite lack of formal evidence.

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.