Integrin activation modulates NMDA and AMPA receptor function of CA1 cells in a dose-related fashion in vivo

2008 ◽  
Vol 1233 ◽  
pp. 20-26 ◽  
Author(s):  
Gábor Juhász ◽  
Gabriella Vass ◽  
Zsolt Bozsó ◽  
Dénes Budai ◽  
Botond Penke ◽  
...  
Keyword(s):  
Ampa Receptor ◽  
Receptor Function ◽  
Integrin Activation ◽  
Ca1 Cells

scholarly journals Disrupted AMPA Receptor Function upon Genetic- or Antibody-Mediated Loss of Autism-Associated CASPR2

2019 ◽  
Vol 29 (12) ◽  
pp. 4919-4931 ◽  
Author(s):  
Dominique Fernandes ◽  
Sandra D Santos ◽  
Ester Coutinho ◽  
Jessica L Whitt ◽  
Nuno Beltrão ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Ampa Receptor ◽  
Ampa Receptors ◽  
Neuropsychiatric Disorders ◽  
Receptor Function ◽  
Loss Of Function ◽  
Excitatory Transmission ◽  
Morvan’S Syndrome

Abstract Neuropsychiatric disorders share susceptibility genes, suggesting a common origin. One such gene is CNTNAP2 encoding contactin-associated protein 2 (CASPR2), which harbours mutations associated to autism, schizophrenia, and intellectual disability. Antibodies targeting CASPR2 have also been recently described in patients with several neurological disorders, such as neuromyotonia, Morvan’s syndrome, and limbic encephalitis. Despite the clear implication of CNTNAP2 and CASPR2 in neuropsychiatric disorders, the pathogenic mechanisms associated with alterations in CASPR2 function are unknown. Here, we show that Caspr2 is expressed in excitatory synapses in the cortex, and that silencing its expression in vitro or in vivo decreases the synaptic expression of α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors and the amplitude of AMPA receptor-mediated currents. Furthermore, Caspr2 loss of function blocks synaptic scaling in vitro and experience-dependent homoeostatic synaptic plasticity in the visual cortex. Patient CASPR2 antibodies decrease the dendritic levels of Caspr2 and synaptic AMPA receptor trafficking, and perturb excitatory transmission in the visual cortex. These results suggest that mutations in CNTNAP2 may contribute to alterations in AMPA receptor function and homoeostatic plasticity, and indicate that antibodies from anti-CASPR2 encephalitis patients affect cortical excitatory transmission.

Integration of in vitro neurotoxicity data with biokinetic modelling for the estimation of in vivo neurotoxicity

2007 ◽  
Vol 26 (4) ◽  
pp. 333-338 ◽  
Author(s):  
Anna Forsby ◽  
Bas Blaauboer
Keyword(s):  
Exposure Period ◽  
Cellular Protein ◽  
In Vitro Toxicity ◽  
Target Tissue ◽  
Receptor Function ◽  
Human Neuroblastoma ◽  
Protein Levels ◽  
Effective Doses

Risk assessment of neurotoxicity is mainly based on in vivo exposure, followed by tests on behaviour, physiology and pathology. In this study, an attempt to estimate lowest observed neurotoxic doses after single or repeated dose exposure was performed. Differentiated human neuroblastoma SH-SY5Y cells were exposed to acrylamide, lindane, parathion, paraoxon, phenytoin, diazepam or caffeine for 72 hours. The effects on protein synthesis and intracellular free Ca2+concentration were studied as physiological endpoints. Voltage operated Ca2 +channel function, acetylcholine receptor function and neurite degenerative effects were investigated as neurospecific endpoints for excitability, cholinergic signal transduction and axonopathy, respectively. The general cytotoxicity, determined as the total cellular protein levels after the 72 hours exposure period, was used for comparison to the specific endpoints and for estimation of acute lethality. The lowest concentration that induced 20% effect (EC 20) obtained for each compound, was used as a surrogate for the lowest neurotoxic level (LOEL) at the target site in vivo. The LOELs were integrated with data on adsorption, distribution, metabolism and excretion of the compounds in physiologically-based biokinetic (PBBK) models of the rat and the lowest observed effective doses (LOEDs) were estimated for the test compounds. A good correlation was observed between the estimated LOEDs and experimental LOEDs found in literature for rat for all test compounds, except for diazepam. However, when using in vitro data from the literature on diazepam's effect on gamma-amino butyric acid (GABA)A receptor function for the estimation of LOED, the correlation between the estimated and experimental LOEDs was improved from a 10 000-fold to a 10-fold difference. Our results indicate that it is possible to estimate LOEDs by integrating in vitro toxicity data as surrogates for lowest observed target tissue levels with PBBK models, provided that some knowledge about toxic mechanisms is known. Human & Experimental Toxicology (2007) 26, 333—338

In vivo characterization of the putative 5-HT1A receptor antagonist SDZ 216,525 using two models of somatodendritic 5-HT1A receptor function

1994 ◽  
Vol 33 (3-4) ◽  
pp. 359-366 ◽  
Author(s):  
C. Routledge ◽  
J. Hartley ◽  
J. Gurling ◽  
M. Ashworth-Preece ◽  
G. Brown ◽  
...  
Keyword(s):  
Receptor Antagonist ◽  
Receptor Function ◽  
In Vivo Characterization

scholarly journals Integrin Activation In Vivo and In Silico

Structure ◽  
2004 ◽  
Vol 12 (12) ◽  
pp. 2096-2098 ◽  
Author(s):  
Mu Gao ◽  
Klaus Schulten
Keyword(s):  
In Silico ◽  
Integrin Activation

Focus on GABAA receptor function

2014 ◽  
Vol 53 (06) ◽  
pp. 227-337 ◽  
Author(s):  
H. Hautzel ◽  
H.-W. Müller ◽  
S. Nikolaus
Keyword(s):  
Gabaa Receptor ◽  
Receptor Binding ◽  
Temporal Cortex ◽  
Primary Diagnosis ◽  
Receptor Function ◽  
Healthy Individuals ◽  
Major Depressive ◽  
Neuropsychiatric Diseases ◽  
Pubmed Search

SummaryImpairment of GABAA receptor function is increasingly recognized to play a major role in the pathophysiology of neuropsychiatric diseases including anxiety disorder (AD), major depressive disorder (MDD) and schizophrenia (SZ). Patients, method: We conducted a PUBMED search, which provided a total of 23 in vivo investigations with PET and SPECT, in which GABAA receptor binding in patients with the primary diagnosis of AD (n = 14, 160 patients, 172 controls), MDD (n = 2, 24 patients, 28 controls) or SZ (n = 6, 77 patients, 90 controls) was compared to healthy individuals. Results: A retrospective analysis revealed that AD, MDD and SZ differed as to both site(s) and extent(s) of GABAergic impairment. Additionally, it may be stated that, while the decline of GABAA receptor binding AD involved the whole mesolimbocortical system, in SZ it was confined to the frontal and temporal cortex. Conclusion: As GABA is known to inhibit dopamine and serotonin, GABAergic dysfunction may be associated with the disturbances of dopaminergic and serotonergic neurotransmission in neuropsychiatric disorders.

scholarly journals (R)-Ketamine Induces a Greater Increase in Prefrontal 5-HT Release Than (S)-Ketamine and Ketamine Metabolites via an AMPA Receptor-Independent Mechanism

2019 ◽  
Vol 22 (10) ◽  
pp. 665-674 ◽  
Author(s):  
Yukio Ago ◽  
Wataru Tanabe ◽  
Momoko Higuchi ◽  
Shinji Tsukada ◽  
Tatsunori Tanaka ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Ampa Receptor ◽  
Dopamine Release ◽  
Molecular Mechanisms ◽  
In Vivo Microdialysis ◽  
Serotonin Release ◽  
Dependent Manner ◽  
Independent Mechanism ◽  
Dose Dependent

Abstract Background Although recent studies provide insight into the molecular mechanisms of the effects of ketamine, the antidepressant mechanism of ketamine enantiomers and their metabolites is not fully understood. In view of the involvement of mechanisms other than the N-methyl-D-aspartate receptor in ketamine’s action, we investigated the effects of (R)-ketamine, (S)-ketamine, (R)-norketamine [(R)-NK], (S)-NK, (2R,6R)-hydroxynorketamine [(2R,6R)-HNK], and (2S,6S)-HNK on monoaminergic neurotransmission in the prefrontal cortex of mice. Methods The extracellular monoamine levels in the prefrontal cortex were measured by in vivo microdialysis. Results (R)-Ketamine and (S)-ketamine acutely increased serotonin release in a dose-dependent manner, and the effect of (R)-ketamine was greater than that of (S)-ketamine. In contrast, (S)-ketamine caused a robust increase in dopamine release compared with (R)-ketamine. Both ketamine enantiomers increased noradrenaline release, but these effects did not differ. (2R,6R)-HNK caused a slight but significant increase in serotonin and noradrenaline but not dopamine release. (S)-NK increased dopamine and noradrenaline but not serotonin release. Differential effects between (R)-ketamine and (S)-ketamine were also observed in a lipopolysaccharide-induced model of depression. An α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptor antagonist, 2,3-dioxo-6-nitro-1,2,3,4- tetrahydrobenzo[f]quinoxaline-7-sulfonamide (NBQX), attenuated (S)-ketamine-induced, but not (R)-ketamine-induced serotonin release, whereas NBQX blocked dopamine release induced by both enantiomers. Local application of (R)-ketamine into the prefrontal cortex caused a greater increase in prefrontal serotonin release than that of (S)-ketamine. Conclusions (R)-Ketamine strongly activates the prefrontal serotonergic system through an AMPA receptor-independent mechanism. (S)-Ketamine-induced serotonin and dopamine release was AMPA receptor-dependent. These findings provide a neurochemical basis for the underlying pharmacological differences between ketamine enantiomers and their metabolites.

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