scholarly journals Synaptic deficits in iPSC-derived cortical interneurons in schizophrenia are mediated by NLGN2 and rescued by N-acetylcysteine

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Annie Kathuria ◽  
Kara Lopez-Lengowski ◽  
Bradley Watmuff ◽  
Donna McPhie ◽  
Bruce M. Cohen ◽  
...  

AbstractHuman postmortem studies suggest a major role for abnormalities in GABAergic interneurons in the prefrontal cortex in schizophrenia. Cortical interneurons differentiated from induced pluripotent stem cells (iPSCs) of schizophrenia subjects showed significantly lower levels of glutamate decarboxylase 67 (GAD67), replicating findings from multiple postmortem studies, as well as reduced levels of synaptic proteins gehpyrin and NLGN2. Co-cultures of the interneurons with excitatory cortical pyramidal neurons from schizophrenia iPSCs showed reduced synaptic puncta density and lower action potential frequency. NLGN2 overexpression in schizophrenia neurons rescued synaptic puncta deficits while NLGN2 knockdown in healthy neurons resulted in reduced synaptic puncta density. Schizophrenia interneurons also had significantly smaller nuclear area, suggesting an innate oxidative stressed state. The antioxidant N-acetylcysteine increased the nuclear area in schizophrenia interneurons, increased NLGN2 expression and rescued synaptic deficits. These results implicate specific deficiencies in the synaptic machinery in cortical interneurons as critical regulators of synaptic connections in schizophrenia and point to a nexus between oxidative stress and NLGN2 expression in mediating synaptic deficits in schizophrenia.

2022 ◽  
Vol 15 ◽  
Author(s):  
Yiwen Chen ◽  
Yuanjia Zheng ◽  
Jinglan Yan ◽  
Chuanan Zhu ◽  
Xuan Zeng ◽  
...  

Early life stress is thought to be a risk factor for emotional disorders, particularly depression and anxiety. Although the excitation/inhibition (E/I) imbalance has been implicated in neuropsychiatric disorders, whether early life stress affects the E/I balance in the medial prefrontal cortex at various developmental stages is unclear. In this study, rats exposed to maternal separation (MS) that exhibited a well-established early life stress paradigm were used to evaluate the E/I balance in adolescence (postnatal day P43–60) and adulthood (P82–100) by behavior tests, whole-cell recordings, and microdialysis coupled with high performance liquid chromatography-mass spectrometry (HPLC-MS) analysis. First, the behavioral tests revealed that MS induced both anxiety- and depressive-like behaviors in adolescent rats but only depressive-like behavior in adult rats. Second, MS increased the action potential frequency and E/I balance of synaptic transmission onto L5 pyramidal neurons in the prelimbic (PrL) brain region of adolescent rats while decreasing the action potential frequency and E/I balance in adult rats. Finally, MS increases extracellular glutamate levels and decreased the paired-pulse ratio of evoked excitatory postsynaptic currents (EPSCs) of pyramidal neurons in the PrL of adolescent rats. In contrast, MS decreased extracellular glutamate levels and increased the paired-pulse ratio of evoked EPSCs of pyramidal neurons in the PrL of adult rats. The present results reveal a key role of E/I balance in different MS-induced disorders may related to the altered probability of presynaptic glutamate release at different developmental stages.


2020 ◽  
Vol 12 (570) ◽  
pp. eabc1492
Author(s):  
Lawrence S. Hsieh ◽  
John H. Wen ◽  
Lena H. Nguyen ◽  
Longbo Zhang ◽  
Stephanie A. Getz ◽  
...  

The causative link between focal cortical malformations (FCMs) and epilepsy is well accepted, especially among patients with focal cortical dysplasia type II (FCDII) and tuberous sclerosis complex (TSC). However, the mechanisms underlying seizures remain unclear. Using a mouse model of TSC- and FCDII-associated FCM, we showed that FCM neurons were responsible for seizure activity via their unexpected abnormal expression of the hyperpolarization-activated cyclic nucleotide–gated potassium channel isoform 4 (HCN4), which is normally not present in cortical pyramidal neurons after birth. Increasing intracellular cAMP concentrations, which preferentially affects HCN4 gating relative to the other isoforms, drove repetitive firing of FCM neurons but not control pyramidal neurons. Ectopic HCN4 expression was dependent on the mechanistic target of rapamycin (mTOR), preceded the onset of seizures, and was also found in diseased neurons in tissue resected from patients with TSC and FCDII. Last, blocking HCN4 channel activity in FCM neurons prevented epilepsy in the mouse model. These findings suggest that HCN4 play a main role in seizure and identify a cAMP-dependent seizure mechanism in TSC and FCDII. Furthermore, the unique expression of HCN4 exclusively in FCM neurons suggests that gene therapy targeting HCN4 might be effective in reducing seizures in FCDII or TSC.


2009 ◽  
Vol 19 (11) ◽  
pp. 2719-2727 ◽  
Author(s):  
J.-R. Chen ◽  
Y.-T. Yan ◽  
T.-J. Wang ◽  
L.-J. Chen ◽  
Y.-J. Wang ◽  
...  

Author(s):  
Annika Winbo ◽  
Suganeya Ramanan ◽  
Emily Eugster ◽  
Annika Rydberg ◽  
Stefan Jovinge ◽  
...  

Sympathetic activation is an established trigger of life-threatening cardiac events in long QT syndrome type 1 (LQT1). KCNQ1 loss-of-function variants, which underlie LQT1, have been associated with both cardiac arrhythmia and neuronal hyperactivity pathologies. However, the LQT1 sympathetic neuronal phenotype is unknown. Here we aimed to study human induced pluripotent stem cell (hiPSC)-derived sympathetic neurons (SNs) to evaluate neuronal functional phenotype in LQT1. We generated hiPSC-SNs from two LQT1 patients with a history of sympathetically triggered arrhythmia and KCNQ1 loss-of-function genotypes (c.781_782delinsTC and p.S349W/p.R518X). Characterisation of hiPSC-SNs was performed using immunohistochemistry, enzyme-linked immunosorbent assay and whole-cell patch clamp electrophysiology, and functional LQT1 hiPSC-SN phenotypes compared to healthy control (WT) hiPSC-SNs. hiPSC-SNs stained positive for tyrosine hydroxylase, peripherin, KCNQ1, and secreted noradrenaline. hiPSC-SNs at 60±2.2 days in vitro had healthy resting membrane potentials (-60±1.3 mV), and fired rapid action potentials with mature kinetics in response to stimulation. Significant hyperactivity in LQT1 hiPSC-SNs was evident via increased noradrenaline release, increased spontaneous action potential frequency, increased total inward current density, and reduced afterhyperpolarisation, compared to age-matched WT hiPSC-SNs. A significantly higher action potential frequency upon current injection and larger synaptic current amplitudes in compound heterozygous p.S349W/p.R518X hiPSC-SNs compared to heterozygous c.781_782delinsTC hiPSC-SNs was also observed, suggesting a potential genotype-phenotype correlation. Together our data reveal increased neurotransmission and excitability in heterozygous and compound heterozygous patient-derived LQT1 sympathetic neurons, suggesting that the cellular arrhythmogenic potential in LQT1 is not restricted to cardiomyocytes.


PLoS ONE ◽  
2010 ◽  
Vol 5 (5) ◽  
pp. e10596 ◽  
Author(s):  
Ning Li ◽  
Chun-Tao Zhao ◽  
Ying Wang ◽  
Xiao-Bing Yuan

2013 ◽  
Vol 218 (6) ◽  
pp. 1407-1417 ◽  
Author(s):  
Jeng-Rung Chen ◽  
Tsyr-Jiuan Wang ◽  
Seh-Hong Lim ◽  
Yueh-Jan Wang ◽  
Guo-Fang Tseng

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