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Reduction of EEG theta power and changes in motor activity in rats treated with ceftriaxone.

Bellesi M, Vyazovskiy VV, Tononi G, Cirelli C, Conti F - PLoS ONE (2012)

Bottom Line: Spectral analysis showed that 8 days of CEF treatment resulted in a delayed reduction in EEG theta power (7-9 Hz) in both frontal and parietal derivations.This decrease peaked at day 10, i.e., 2 days after the end of treatment, and disappeared by day 16.In addition, we found that the same CEF treatment increased motor activity, especially when EEG changes are more prominent.

View Article: PubMed Central - PubMed

Affiliation: Department of Experimental and Clinical Medicine, Section of Neuroscience and Cell Biology, Università Politecnica delle Marche, Ancona, Italy.

ABSTRACT
The glutamate transporter GLT-1 is responsible for the largest proportion of total glutamate transport. Recently, it has been demonstrated that ceftriaxone (CEF) robustly increases GLT-1 expression. In addition, physiological studies have shown that GLT-1 up-regulation strongly affects synaptic plasticity, and leads to an impairment of the prepulse inhibition, a simple form of information processing, thus suggesting that GLT-1 over-expression may lead to dysfunctions of large populations of neurons. To test this possibility, we assessed whether CEF affects cortical electrical activity by using chronic electroencephalographic (EEG) recordings in male WKY rats. Spectral analysis showed that 8 days of CEF treatment resulted in a delayed reduction in EEG theta power (7-9 Hz) in both frontal and parietal derivations. This decrease peaked at day 10, i.e., 2 days after the end of treatment, and disappeared by day 16. In addition, we found that the same CEF treatment increased motor activity, especially when EEG changes are more prominent. Taken together, these data indicate that GLT-1 up-regulation, by modulating glutamatergic transmission, impairs the activity of widespread neural circuits. In addition, the increased motor activity and prepulse inhibition alterations previously described suggest that neural circuits involved in sensorimotor control are particularly sensitive to GLT-1 up-regulation.

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Effects of ceftriaxone treatment on motor activity.A. Time-course of the amount of time expressed in 4s epochs spent in waking, NREM and REM sleep. Values are expressed as mean ± sem. B. Example of EMG activity during the entire length of the experiments. Note the intense activity after the end of CEF treatment. The grey line represents the threshold above and below which the motor activity is identified as active waking or quiet waking, respectively. C–D. Quantitative analysis of EMG activity (C) and Motion activity (D) during active and quiet waking for light and dark periods. Values are relative to the baseline (day 0) and expressed as mean ± sem. * (p<0.05), ** (p<0.01). E–F. Negative correlation between the time-course of relative theta power and the EMG (E) or Motion activity (F).
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pone-0034139-g003: Effects of ceftriaxone treatment on motor activity.A. Time-course of the amount of time expressed in 4s epochs spent in waking, NREM and REM sleep. Values are expressed as mean ± sem. B. Example of EMG activity during the entire length of the experiments. Note the intense activity after the end of CEF treatment. The grey line represents the threshold above and below which the motor activity is identified as active waking or quiet waking, respectively. C–D. Quantitative analysis of EMG activity (C) and Motion activity (D) during active and quiet waking for light and dark periods. Values are relative to the baseline (day 0) and expressed as mean ± sem. * (p<0.05), ** (p<0.01). E–F. Negative correlation between the time-course of relative theta power and the EMG (E) or Motion activity (F).

Mentions: Since changes in theta activity are strongly associated to changes in motor behavior in rats [27]–[29], we investigated whether our animals showed motor abnormalities due to CEF treatment. Firstly, we determined whether CEF treatment modifies the time spent in waking and sleep, in order to rule out that changes in motor activity were simply a consequence of changes in wake duration. To this aim, we performed a quantitative analysis of the total amount of waking, NREM and REM sleep epochs scored, and found no significant differences, neither during the 10 days of treatment nor afterwards [waking: F(5,25) = 0.98, ns; NREM: F(5,25) = 1.2, ns; REM: F(5,25) = 0.26, ns; Figure 3A].


Reduction of EEG theta power and changes in motor activity in rats treated with ceftriaxone.

Bellesi M, Vyazovskiy VV, Tononi G, Cirelli C, Conti F - PLoS ONE (2012)

Effects of ceftriaxone treatment on motor activity.A. Time-course of the amount of time expressed in 4s epochs spent in waking, NREM and REM sleep. Values are expressed as mean ± sem. B. Example of EMG activity during the entire length of the experiments. Note the intense activity after the end of CEF treatment. The grey line represents the threshold above and below which the motor activity is identified as active waking or quiet waking, respectively. C–D. Quantitative analysis of EMG activity (C) and Motion activity (D) during active and quiet waking for light and dark periods. Values are relative to the baseline (day 0) and expressed as mean ± sem. * (p<0.05), ** (p<0.01). E–F. Negative correlation between the time-course of relative theta power and the EMG (E) or Motion activity (F).
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3316604&req=5

pone-0034139-g003: Effects of ceftriaxone treatment on motor activity.A. Time-course of the amount of time expressed in 4s epochs spent in waking, NREM and REM sleep. Values are expressed as mean ± sem. B. Example of EMG activity during the entire length of the experiments. Note the intense activity after the end of CEF treatment. The grey line represents the threshold above and below which the motor activity is identified as active waking or quiet waking, respectively. C–D. Quantitative analysis of EMG activity (C) and Motion activity (D) during active and quiet waking for light and dark periods. Values are relative to the baseline (day 0) and expressed as mean ± sem. * (p<0.05), ** (p<0.01). E–F. Negative correlation between the time-course of relative theta power and the EMG (E) or Motion activity (F).
Mentions: Since changes in theta activity are strongly associated to changes in motor behavior in rats [27]–[29], we investigated whether our animals showed motor abnormalities due to CEF treatment. Firstly, we determined whether CEF treatment modifies the time spent in waking and sleep, in order to rule out that changes in motor activity were simply a consequence of changes in wake duration. To this aim, we performed a quantitative analysis of the total amount of waking, NREM and REM sleep epochs scored, and found no significant differences, neither during the 10 days of treatment nor afterwards [waking: F(5,25) = 0.98, ns; NREM: F(5,25) = 1.2, ns; REM: F(5,25) = 0.26, ns; Figure 3A].

Bottom Line: Spectral analysis showed that 8 days of CEF treatment resulted in a delayed reduction in EEG theta power (7-9 Hz) in both frontal and parietal derivations.This decrease peaked at day 10, i.e., 2 days after the end of treatment, and disappeared by day 16.In addition, we found that the same CEF treatment increased motor activity, especially when EEG changes are more prominent.

View Article: PubMed Central - PubMed

Affiliation: Department of Experimental and Clinical Medicine, Section of Neuroscience and Cell Biology, Università Politecnica delle Marche, Ancona, Italy.

ABSTRACT
The glutamate transporter GLT-1 is responsible for the largest proportion of total glutamate transport. Recently, it has been demonstrated that ceftriaxone (CEF) robustly increases GLT-1 expression. In addition, physiological studies have shown that GLT-1 up-regulation strongly affects synaptic plasticity, and leads to an impairment of the prepulse inhibition, a simple form of information processing, thus suggesting that GLT-1 over-expression may lead to dysfunctions of large populations of neurons. To test this possibility, we assessed whether CEF affects cortical electrical activity by using chronic electroencephalographic (EEG) recordings in male WKY rats. Spectral analysis showed that 8 days of CEF treatment resulted in a delayed reduction in EEG theta power (7-9 Hz) in both frontal and parietal derivations. This decrease peaked at day 10, i.e., 2 days after the end of treatment, and disappeared by day 16. In addition, we found that the same CEF treatment increased motor activity, especially when EEG changes are more prominent. Taken together, these data indicate that GLT-1 up-regulation, by modulating glutamatergic transmission, impairs the activity of widespread neural circuits. In addition, the increased motor activity and prepulse inhibition alterations previously described suggest that neural circuits involved in sensorimotor control are particularly sensitive to GLT-1 up-regulation.

Show MeSH
Related in: MedlinePlus