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Knockdown of mental disorder susceptibility genes disrupts neuronal network physiology in vitro.

MacLaren EJ, Charlesworth P, Coba MP, Grant SG - Mol. Cell. Neurosci. (2011)

Bottom Line: Measurement of multiple neural network parameters demonstrated phenotypes for these genes compared with controls.Moreover, the different genes disrupted network properties and showed distinct and overlapping effects.These data show multiple susceptibility genes for complex psychiatric disorders, regulate neural network physiology and demonstrate a new assay system with wide application.

View Article: PubMed Central - PubMed

Affiliation: Genes to Cognition Programme, Wellcome Trust Sanger Institute, Hinxton, Cambridge CB101SA, UK.

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Related in: MedlinePlus

Tnik knockdown affects network phenotypes. (a) Raster plots of network firing recorded on DIV 7 in an untransfected and Tnik knockdown culture showing 2 min of activity across all active electrodes. Each horizontal row represents one electrode on the MEA and each tic-mark represents a spike detected by the electrode. Closely packed tics, such as those that are boxed represent bursts. (b) Percentage of spikes in bursts (Burst Spikes) is increased while the burst rate is reduced in cultures transfected with siRNAs targeting Tnik as represented by the red bars. Additionally, the burst pattern parameter is reduced and the correlation index is increased, both indicative of increased synchrony in network bursting. Untransfected and NTC treated cultures are shown in blue and green bars respectively, while Tnik knockdowns are plotted in red. Mean data are plotted (±SEM). The data were analyzed by ANOVA and Fisher's PLSD post-hoc tests. *p <  0.05 and **p < 0.01.
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f0010: Tnik knockdown affects network phenotypes. (a) Raster plots of network firing recorded on DIV 7 in an untransfected and Tnik knockdown culture showing 2 min of activity across all active electrodes. Each horizontal row represents one electrode on the MEA and each tic-mark represents a spike detected by the electrode. Closely packed tics, such as those that are boxed represent bursts. (b) Percentage of spikes in bursts (Burst Spikes) is increased while the burst rate is reduced in cultures transfected with siRNAs targeting Tnik as represented by the red bars. Additionally, the burst pattern parameter is reduced and the correlation index is increased, both indicative of increased synchrony in network bursting. Untransfected and NTC treated cultures are shown in blue and green bars respectively, while Tnik knockdowns are plotted in red. Mean data are plotted (±SEM). The data were analyzed by ANOVA and Fisher's PLSD post-hoc tests. *p <  0.05 and **p < 0.01.

Mentions: The network effects of knocking down Tnik in these cultures were the most dramatic as shown in Fig. 2. The effect was dramatic enough to be observed by raster plot of the firing frequency recorded by the electrodes of the MEAs (Fig. 2a). The significantly altered parameters included: increased percentage of spikes in bursts, decreased duration of bursts and increased coordination of bursting activity across neurons in the network as reflected by the decreased burst pattern and increased correlation index parameters. All quantitative data is shown in Supplementary Table 2. The burst correlation in particular is of interest because of the connection between schizophrenia and neural network synchrony. In all cases the effect observed becomes significant only after 7 DIV, indicating that the networks remained normal for at least three days after application of the siRNA, and remained significant through the 12th day of culture. The delayed onset of effect after the application of the siRNA could be due to the time it takes for protein to turnover in the cell after new translation has stopped. The 11–12 DIV timepoint is past the expected efficacy of siRNA treatment, and could also suggest the protein turnover “lag” between translation and function. However, it may also indicate irreversible effects to the development of neuronal networks that cannot be compensated at a later time.


Knockdown of mental disorder susceptibility genes disrupts neuronal network physiology in vitro.

MacLaren EJ, Charlesworth P, Coba MP, Grant SG - Mol. Cell. Neurosci. (2011)

Tnik knockdown affects network phenotypes. (a) Raster plots of network firing recorded on DIV 7 in an untransfected and Tnik knockdown culture showing 2 min of activity across all active electrodes. Each horizontal row represents one electrode on the MEA and each tic-mark represents a spike detected by the electrode. Closely packed tics, such as those that are boxed represent bursts. (b) Percentage of spikes in bursts (Burst Spikes) is increased while the burst rate is reduced in cultures transfected with siRNAs targeting Tnik as represented by the red bars. Additionally, the burst pattern parameter is reduced and the correlation index is increased, both indicative of increased synchrony in network bursting. Untransfected and NTC treated cultures are shown in blue and green bars respectively, while Tnik knockdowns are plotted in red. Mean data are plotted (±SEM). The data were analyzed by ANOVA and Fisher's PLSD post-hoc tests. *p <  0.05 and **p < 0.01.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC3105225&req=5

f0010: Tnik knockdown affects network phenotypes. (a) Raster plots of network firing recorded on DIV 7 in an untransfected and Tnik knockdown culture showing 2 min of activity across all active electrodes. Each horizontal row represents one electrode on the MEA and each tic-mark represents a spike detected by the electrode. Closely packed tics, such as those that are boxed represent bursts. (b) Percentage of spikes in bursts (Burst Spikes) is increased while the burst rate is reduced in cultures transfected with siRNAs targeting Tnik as represented by the red bars. Additionally, the burst pattern parameter is reduced and the correlation index is increased, both indicative of increased synchrony in network bursting. Untransfected and NTC treated cultures are shown in blue and green bars respectively, while Tnik knockdowns are plotted in red. Mean data are plotted (±SEM). The data were analyzed by ANOVA and Fisher's PLSD post-hoc tests. *p <  0.05 and **p < 0.01.
Mentions: The network effects of knocking down Tnik in these cultures were the most dramatic as shown in Fig. 2. The effect was dramatic enough to be observed by raster plot of the firing frequency recorded by the electrodes of the MEAs (Fig. 2a). The significantly altered parameters included: increased percentage of spikes in bursts, decreased duration of bursts and increased coordination of bursting activity across neurons in the network as reflected by the decreased burst pattern and increased correlation index parameters. All quantitative data is shown in Supplementary Table 2. The burst correlation in particular is of interest because of the connection between schizophrenia and neural network synchrony. In all cases the effect observed becomes significant only after 7 DIV, indicating that the networks remained normal for at least three days after application of the siRNA, and remained significant through the 12th day of culture. The delayed onset of effect after the application of the siRNA could be due to the time it takes for protein to turnover in the cell after new translation has stopped. The 11–12 DIV timepoint is past the expected efficacy of siRNA treatment, and could also suggest the protein turnover “lag” between translation and function. However, it may also indicate irreversible effects to the development of neuronal networks that cannot be compensated at a later time.

Bottom Line: Measurement of multiple neural network parameters demonstrated phenotypes for these genes compared with controls.Moreover, the different genes disrupted network properties and showed distinct and overlapping effects.These data show multiple susceptibility genes for complex psychiatric disorders, regulate neural network physiology and demonstrate a new assay system with wide application.

View Article: PubMed Central - PubMed

Affiliation: Genes to Cognition Programme, Wellcome Trust Sanger Institute, Hinxton, Cambridge CB101SA, UK.

Show MeSH
Related in: MedlinePlus