scholarly journals Deficiency of autism risk factor ASH1L in prefrontal cortex induces epigenetic aberrations and seizures

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Luye Qin ◽  
Jamal B. Williams ◽  
Tao Tan ◽  
Tiaotiao Liu ◽  
Qing Cao ◽  
...  

AbstractASH1L, a histone methyltransferase, is identified as a top-ranking risk factor for autism spectrum disorder (ASD), however, little is known about the biological mechanisms underlying the link of ASH1L haploinsufficiency to ASD. Here we show that ASH1L expression and H3K4me3 level are significantly decreased in the prefrontal cortex (PFC) of postmortem tissues from ASD patients. Knockdown of Ash1L in PFC of juvenile mice induces the downregulation of risk genes associated with ASD, intellectual disability (ID) and epilepsy. These downregulated genes are enriched in excitatory and inhibitory synaptic function and have decreased H3K4me3 occupancy at their promoters. Furthermore, Ash1L deficiency in PFC causes the diminished GABAergic inhibition, enhanced glutamatergic transmission, and elevated PFC pyramidal neuronal excitability, which is associated with severe seizures and early mortality. Chemogenetic inhibition of PFC pyramidal neuronal activity, combined with the administration of GABA enhancer diazepam, rescues PFC synaptic imbalance and seizures, but not autistic social deficits or anxiety-like behaviors. These results have revealed the critical role of ASH1L in regulating synaptic gene expression and seizures, which provides insights into treatment strategies for ASH1L-associated brain diseases.

2021 ◽  
Vol 44 (1) ◽  
Author(s):  
Masaki Isoda

As a frontal node in the primate social brain, the medial prefrontal cortex (MPFC) plays a critical role in coordinating one's own behavior with respect to that of others. Current literature demonstrates that single neurons in the MPFC encode behavior-related variables such as intentions, actions, and rewards, specifically for self and other, and that the MPFC comes into play when reflecting upon oneself and others. The social moderator account of MPFC function can explain maladaptive social cognition in people with autism spectrum disorder, which tips the balance in favor of self-centered perspectives rather than taking into consideration the perspective of others. Several strands of evidence suggest a hypothesis that the MPFC represents different other mental models, depending on the context at hand, to better predict others’ emotions and behaviors. This hypothesis also accounts for aberrant MPFC activity in autistic individuals while they are mentalizing others. Expected final online publication date for the Annual Review of Neuroscience, Volume 44 is July 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2008 ◽  
Vol 15 (2) ◽  
pp. 50-59 ◽  
Author(s):  
Amy Philofsky

AbstractRecent prevalence estimates for autism have been alarming as a function of the notable increase. Speech-language pathologists play a critical role in screening, assessment and intervention for children with autism. This article reviews signs that may be indicative of autism at different stages of language development, and discusses the importance of several psychometric properties—sensitivity and specificity—in utilizing screening measures for children with autism. Critical components of assessment for children with autism are reviewed. This article concludes with examples of intervention targets for children with ASD at various levels of language development.


Author(s):  
Leandro F. Vendruscolo ◽  
George F. Koob

Alcohol use disorder is a chronically relapsing disorder that involves (1) compulsivity to seek and take alcohol, (2) difficulty in limiting alcohol intake, and (3) emergence of a negative emotional state (e.g., dysphoria, anxiety, irritability) in the absence of alcohol. Alcohol addiction encompasses a three-stage cycle that becomes more intense as alcohol use progresses: binge/intoxication, withdrawal/negative affect, and preoccupation/anticipation. These stages engage neuroadaptations in brain circuits that involve the basal ganglia (reward hypofunction), extended amygdala (stress sensitization), and prefrontal cortex (executive function disorder). This chapter discusses key neuroadaptations in the hypothalamic and extrahypothalamic stress systems and the critical role of glucocorticoid receptors. These neuroadaptations contribute to negative emotional states that powerfully drive compulsive alcohol drinking and seeking. These changes in association with a disruption of prefrontal cortex function that lead to cognitive deficits and poor decision making contribute to the chronic relapsing nature of alcohol dependence.


2021 ◽  
Vol 168 ◽  
pp. 138-145
Author(s):  
Yuan-Mei Wang ◽  
Ming-Yue Qiu ◽  
Qing Liu ◽  
Huang Tang ◽  
Hong-Feng Gu

Antioxidants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1575
Author(s):  
Francisco J. Carvajal ◽  
Waldo Cerpa

Traumatic Brain Injury (TBI) mediates neuronal death through several events involving many molecular pathways, including the glutamate-mediated excitotoxicity for excessive stimulation of N-methyl-D-aspartate receptors (NMDARs), producing activation of death signaling pathways. However, the contribution of NMDARs (distribution and signaling-associated to the distribution) remains incompletely understood. We propose a critical role of STEP61 (Striatal-Enriched protein tyrosine phosphatase) in TBI; this phosphatase regulates the dephosphorylated state of the GluN2B subunit through two pathways: by direct dephosphorylation of tyrosine-1472 and indirectly via dephosphorylation and inactivation of Fyn kinase. We previously demonstrated oxidative stress’s contribution to NMDAR signaling and distribution using SOD2+/− mice such a model. We performed TBI protocol using a controlled frontal impact device using C57BL/6 mice and SOD2+/− animals. After TBI, we found alterations in cognitive performance, NMDAR-dependent synaptic function (decreased synaptic form of NMDARs and decreased synaptic current NMDAR-dependent), and increased STEP61 activity. These changes are reduced partially with the STEP61-inhibitor TC-2153 treatment in mice subjected to TBI protocol. This study contributes with evidence about the role of STEP61 in the neuropathological progression after TBI and also the alteration in their activity, such as an early biomarker of synaptic damage in traumatic lesions.


2020 ◽  
pp. 107385842097571
Author(s):  
Darakhshan Jabeen Haleem

There is growing increase in the global prevalence of depression, but treatment outcome of this highly disabling disease is not satisfactory. Many patients are not benefitted by the currently prescribed antidepressants—together with this partial remission is very common. Improving treatment strategies and developing better therapeutic agents for treating depression is therefore highly needed. Stress-related epigenetic changes play a critical role in the pathogenesis as well as treatment of depression. Stressful events activate hypothalamic-pituitary-adrenal axis to increase circulating levels of glucocorticoids (GCs), and a greater sensitivity to this fright and flight response increases risk of depression. A role of serotonin (5-hydroxytryptamine; 5-HT) in responses to stress and in the pathogenesis and treatment of depression is well established. Substantial evidence supports a critical role of 5-HT1A receptors in these effects of 5-HT. The present article targets stress-induced higher and sustained increases of GCs and mediated influences on the physiological as well transcriptional regulation of 5-HT1A receptors to evaluate their causal role in the pathogenesis of depression. It is suggested that synthetic compounds with antagonist activity for GC receptors and agonist activity for 5-HT1A receptors may prove better therapeutic agents for treating depression.


2006 ◽  
Vol 95 (5) ◽  
pp. 3286-3290 ◽  
Author(s):  
Jeannie Chin ◽  
Rong-Yu Liu ◽  
Leonard J. Cleary ◽  
Arnold Eskin ◽  
John H. Byrne

Transforming growth factor beta-1 (TGF-β1) plays important roles in the early development of the nervous system and has been implicated in neuronal plasticity in adult organisms. It induces long-term increases in sensory neuron excitability in Aplysia as well as a long-term enhancement of synaptic efficacy at sensorimotor synapses. In addition, TGF-β1 acutely regulates synapsin phosphorylation and reduces synaptic depression induced by low-frequency stimuli. Because of the critical role of MAPK in other forms of long-term plasticity in Aplysia, we examined the role of MAPK in TGF-β1-induced long-term changes in neuronal excitability. Prolonged (6 h) exposure to TGF-β1 induced long-term increases in excitability. We confirmed this finding and now report that exposure to TGF-β1 was sufficient to activate MAPK and increase nuclear levels of active MAPK. Moreover, TGF-β1 enhanced phosphorylation of the Aplysia transcriptional activator cAMP response element binding protein (CREB)1, a homologue to vertebrate CREB. Both the TGF-β1-induced long-term changes in neuronal excitability and the phosphorylation of CREB1 were blocked in the presence of an inhibitor of the MAPK cascade, confirming a role for MAPK in long-term modulation of sensory neuron function.


2004 ◽  
Vol 286 (5) ◽  
pp. R894-R902 ◽  
Author(s):  
K. J. Latchford ◽  
A. V. Ferguson

The hypothalamic paraventricular nucleus (PVN) plays a critical role in cardiovascular and neuroendocrine regulation. ANG II (ANG) acts throughout the periphery in the maintenance of fluid-electrolyte homeostasis and has also been demonstrated to act as a neurotransmitter in PVN exerting considerable influence on neuronal excitability in this nucleus. The mechanisms underlying the ANG-mediated excitation of PVN magnocellular neurons have yet to be determined. We have used whole cell patch-clamp techniques in hypothalamic slices to examine the effects of ANG on magnocellular neurons. Application of ANG resulted in a depolarization of magnocellular neurons, a response that was abolished in TTX, suggesting an indirect mechanism of action. Interestingly, ANG also increased the frequency of excitatory postsynaptic potentials/currents in magnocellular neurons, an effect that was abolished after application of the glutamate antagonist kynurenic acid. ANG was without effect on the amplitude of excitatory postsynaptic currents, suggesting a presynaptic action on an excitatory interneuron within PVN. The ANG-induced depolarization was shown to be sensitive to kynurenic acid, revealing the requisite role of glutamate in mediating the ANG-induced excitation of magnocellular neurons. These observations indicate that the ANGergic excitation of magnocellular PVN neurons are dependent on an increase in glutamatergic input and thus highlight the importance of a glutamate interneuron in mediating the effects of this neurotransmitter.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Hiroyuki Kato ◽  
Yusuke Iizawa ◽  
Kei Nakamura ◽  
Kazuyuki Gyoten ◽  
Aoi Hayasaki ◽  
...  

In accordance with previous reports, the incidence of biliary candidiasis (BC) after pancreaticoduodenectomy (PD) was reported to be 0 to 5%, and the clinical significance of BC still has been elusive. In this study, we prospectively evaluated the precise incidence of BC after PD using the CHROMagar Candida plate in an attempt to elucidate whether BC has a significant impact on the clinical outcomes after PD.Patients and Method. From November 2014 to March 2016, the consecutive 51 patients who underwent PD were enrolled for this study. The bile juice was prospectively collected through the biliary stent tube on postoperative days (POD) 3, 7, and 14 and directly incubated onto the CHROMagar Candida plate for the cultivation of various Candida species. In the presence or absence of BC, we compared the incidence of SSIs.Results. The incidence of postoperative BC was 15% on POD 3, 24% on POD 7, and 39% on POD 14, respectively. Taken together, 22 patients out of 51 (43.1%) developed BC after PD. Moreover, the incidence of SSIs was significantly higher in patients with BC than in those without it (71% versus 7%, p=0.005). BC was selected as the only significant risk factor of SSIs after PD among the various risk factors. Even though a cause of BC is unknown, high level of alkaline phosphatase (cut-off line >300 IU/L) was selected as the only preoperative risk factor of the development of BC.Conclusion. We elucidated new evidence in which BC could be the independent cause of SSIs after PD and should not be recognized as just contamination artifacts. Preoperative assessment for identifying carriers of Candida species might be essential for reducing the incidence of SSIs after PD.


2005 ◽  
Vol 17 (5) ◽  
pp. 832-846 ◽  
Author(s):  
David M. Schnyer ◽  
Lindsay Nicholls ◽  
Mieke Verfaellie

Making judgments about the retrievability of information is a critical part of the metamemory processes engaged during remembering. A recent study of patients with frontal lesions suggests that ventral medial prefrontal cortex (VMPC) plays a critical role in such judgments [Schnyer, D. M., Verfaellie, M., Alexander, M. P., Lafleche, G., Nicholls, L., & Kaszniak, A. W. A role for right medial prefrontal cortex in accurate feeling of knowing judgments: Evidence from patients with lesions to frontal cortex. Neuropsychologia, 42, 957–966, 2004]. The observed impairment was thought to reflect an inability to determine the accessibility of memory contents. To further examine the neuroanatomical basis of content accessibility assessment, we used fMRI in an episodic feeling-of-knowing (FOK) paradigm. Participants were asked to make trial-by-trial predictions about the retrievability of the final word that completed studied sentences and then to select the correct completion from among alternatives. Results indicated that the VMPC is engaged during accurate FOK judgments and its activation is modulated by retrieval rating. Structural equations modeling supported the notion that VMPC, as part of a broader left hemisphere network involved in memory retrieval, monitors the output of the retrieval process. More generally, VMPC may participate in metacognitive processes that allow for the comparison of available data against an internal model.


Sign in / Sign up

Export Citation Format

Share Document