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Malondialdehyde suppresses cerebral function by breaking homeostasis between excitation and inhibition in turtle Trachemys scripta.

Li F, Yang Z, Lu Y, Wei Y, Wang J, Yin D, He R - PLoS ONE (2010)

Bottom Line: These changes were found associated with the deterioration of encoding action potentials in cortical neurons.In addition, MDA increased the ratio of γ-aminobutyric acid to glutamate in turtle's brain, as well as the sensitivity of GABAergic neurons to inputs compared to excitatory neurons.Therefore, MDA, as a metabolic product in the brain, may weaken cerebral function during carbonyl stress through breaking the homeostasis between excitatory and inhibitory neurons.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.

ABSTRACT
The levels of malondialdehyde (MDA) are high in the brain during carbonyl stress, such as following daily activities and sleep deprivation. To examine our hypothesis that MDA is one of the major substances in the brain leading to fatigue, the influences of MDA on brain functions and neuronal encodings in red-eared turtle (Trachemys scripta) were studied. The intrathecal injections of MDA brought about sleep-like EEG and fatigue-like behaviors in a dose-dependent manner. These changes were found associated with the deterioration of encoding action potentials in cortical neurons. In addition, MDA increased the ratio of γ-aminobutyric acid to glutamate in turtle's brain, as well as the sensitivity of GABAergic neurons to inputs compared to excitatory neurons. Therefore, MDA, as a metabolic product in the brain, may weaken cerebral function during carbonyl stress through breaking the homeostasis between excitatory and inhibitory neurons.

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Quantified EEG power density analysis before and under the MDA treatment.The time course of EEG power density of different frequency was monitored under 20 µM MDA treatment (panel a) and that of control (panel b). Data were means from 15 turtles (n = 15), respectively. The statistic data are shown in Tab. 1.
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pone-0015325-g002: Quantified EEG power density analysis before and under the MDA treatment.The time course of EEG power density of different frequency was monitored under 20 µM MDA treatment (panel a) and that of control (panel b). Data were means from 15 turtles (n = 15), respectively. The statistic data are shown in Tab. 1.

Mentions: In order to see a strong effect of MDA on the behavior and EEG, a high MDA concentration treatment was performed. Similar but stronger EEG changes were observed when turtles were treated with 20 µM/kg MDA than that with 2 µM MDA (Fig. 1). The intrathecal treatment of 20 µM/kg MDA induced, with a latency of 3–5 minutes, an almost complete suppression of EEG signal with irregular spike waves. This period lasted for 2–3 minutes on average. Subsequent EEG tracings were characterized by slow waves that gradually increased in amplitude to reach values remarkably higher than basal waves as control. Quantified EEG analysis revealed statistically significant changes of power density in all 4 frequency bands (Tab. 1 and Fig. 2). The heart rates after 20 µM MDA treatment (16 beats/minutes on average, also showed a significant change, compared with those before the treatment (24 beats/minutes on average). Under 20 µM MDA treatment, some turtles rested their heads on the experimental platform, with relaxed necks, closed eyes, and extended legs out of their shells. Their reaction threshold to stimuli was remarkably increased after the treatment. These results indicate that the carbonyl stress significantly affect the cerebral activity of the turtles in a concentration dependent manner, suggesting a suppression of the animal related to MDA.


Malondialdehyde suppresses cerebral function by breaking homeostasis between excitation and inhibition in turtle Trachemys scripta.

Li F, Yang Z, Lu Y, Wei Y, Wang J, Yin D, He R - PLoS ONE (2010)

Quantified EEG power density analysis before and under the MDA treatment.The time course of EEG power density of different frequency was monitored under 20 µM MDA treatment (panel a) and that of control (panel b). Data were means from 15 turtles (n = 15), respectively. The statistic data are shown in Tab. 1.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3008675&req=5

pone-0015325-g002: Quantified EEG power density analysis before and under the MDA treatment.The time course of EEG power density of different frequency was monitored under 20 µM MDA treatment (panel a) and that of control (panel b). Data were means from 15 turtles (n = 15), respectively. The statistic data are shown in Tab. 1.
Mentions: In order to see a strong effect of MDA on the behavior and EEG, a high MDA concentration treatment was performed. Similar but stronger EEG changes were observed when turtles were treated with 20 µM/kg MDA than that with 2 µM MDA (Fig. 1). The intrathecal treatment of 20 µM/kg MDA induced, with a latency of 3–5 minutes, an almost complete suppression of EEG signal with irregular spike waves. This period lasted for 2–3 minutes on average. Subsequent EEG tracings were characterized by slow waves that gradually increased in amplitude to reach values remarkably higher than basal waves as control. Quantified EEG analysis revealed statistically significant changes of power density in all 4 frequency bands (Tab. 1 and Fig. 2). The heart rates after 20 µM MDA treatment (16 beats/minutes on average, also showed a significant change, compared with those before the treatment (24 beats/minutes on average). Under 20 µM MDA treatment, some turtles rested their heads on the experimental platform, with relaxed necks, closed eyes, and extended legs out of their shells. Their reaction threshold to stimuli was remarkably increased after the treatment. These results indicate that the carbonyl stress significantly affect the cerebral activity of the turtles in a concentration dependent manner, suggesting a suppression of the animal related to MDA.

Bottom Line: These changes were found associated with the deterioration of encoding action potentials in cortical neurons.In addition, MDA increased the ratio of γ-aminobutyric acid to glutamate in turtle's brain, as well as the sensitivity of GABAergic neurons to inputs compared to excitatory neurons.Therefore, MDA, as a metabolic product in the brain, may weaken cerebral function during carbonyl stress through breaking the homeostasis between excitatory and inhibitory neurons.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.

ABSTRACT
The levels of malondialdehyde (MDA) are high in the brain during carbonyl stress, such as following daily activities and sleep deprivation. To examine our hypothesis that MDA is one of the major substances in the brain leading to fatigue, the influences of MDA on brain functions and neuronal encodings in red-eared turtle (Trachemys scripta) were studied. The intrathecal injections of MDA brought about sleep-like EEG and fatigue-like behaviors in a dose-dependent manner. These changes were found associated with the deterioration of encoding action potentials in cortical neurons. In addition, MDA increased the ratio of γ-aminobutyric acid to glutamate in turtle's brain, as well as the sensitivity of GABAergic neurons to inputs compared to excitatory neurons. Therefore, MDA, as a metabolic product in the brain, may weaken cerebral function during carbonyl stress through breaking the homeostasis between excitatory and inhibitory neurons.

Show MeSH
Related in: MedlinePlus