Limits...
Effects of diazepam on glutamatergic synaptic transmission in the hippocampal CA1 area of rats with traumatic brain injury.

Cao L, Bie X, Huo S, Du J, Liu L, Song W - Neural Regen Res (2014)

Bottom Line: Diazepam significantly decreased the numbers of spikes evoked by super stimuli in the presence of 15 μmol/L bicuculline, indicating the existence of inhibitory pathways in the injured rat hippocampus.Diazepam effectively increased the paired-pulse facilitation ratio in the hippocampal CA1 region following fluid percussion injury, reduced miniature excitatory postsynaptic potentials, decreased action-potential-dependent glutamine release, and reversed spontaneous glutamine release.These data suggest that diazepam could decrease the fluid percussion injury-induced enhancement of excitatory synaptic transmission in the rat hippocampal CA1 area.

View Article: PubMed Central - PubMed

Affiliation: Department of Functional Neurosurgery, Xi'an Red Cross Hospital, Xi'an, Shaanxi Province, China ; Department of Rehabilitation Medicine, Xuanwu Hospital, Capital Medical University, Beijing, China.

ABSTRACT
The activity of the Schaffer collaterals of hippocampal CA3 neurons and hippocampal CA1 neurons has been shown to increase after fluid percussion injury. Diazepam can inhibit the hyperexcitability of rat hippocampal neurons after injury, but the mechanism by which it affects excitatory synaptic transmission remains poorly understood. Our results showed that diazepam treatment significantly increased the slope of input-output curves in rat neurons after fluid percussion injury. Diazepam significantly decreased the numbers of spikes evoked by super stimuli in the presence of 15 μmol/L bicuculline, indicating the existence of inhibitory pathways in the injured rat hippocampus. Diazepam effectively increased the paired-pulse facilitation ratio in the hippocampal CA1 region following fluid percussion injury, reduced miniature excitatory postsynaptic potentials, decreased action-potential-dependent glutamine release, and reversed spontaneous glutamine release. These data suggest that diazepam could decrease the fluid percussion injury-induced enhancement of excitatory synaptic transmission in the rat hippocampal CA1 area.

No MeSH data available.


Related in: MedlinePlus

Effect of diazepam (DZ) on the miniature excitatory postsynaptic potentials (mEPSPs) in rat hippocampal CA1 pyramidal neurons following fluid percussion injury (FPI).The number in the brackets represents the number of rats. There were 19 and 12 pyramidal neurons in FPI and FPI + DZ groups, respectively. Quantitative data were expressed as the mean ± SD and analyzed by one-way analysis of variance. Student-Newman-Keuls tests were used for specific comparisons. *P < 0.05, vs. FPI group.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4281428&req=5

Figure 3: Effect of diazepam (DZ) on the miniature excitatory postsynaptic potentials (mEPSPs) in rat hippocampal CA1 pyramidal neurons following fluid percussion injury (FPI).The number in the brackets represents the number of rats. There were 19 and 12 pyramidal neurons in FPI and FPI + DZ groups, respectively. Quantitative data were expressed as the mean ± SD and analyzed by one-way analysis of variance. Student-Newman-Keuls tests were used for specific comparisons. *P < 0.05, vs. FPI group.

Mentions: To investigate a possible contribution of postsynaptic mechanisms in this enhancement, we analyzed the number of miniature excitatory postsynaptic potentials. Under the experimental conditions, the spontaneous miniature excitatory postsynaptic potentials were recorded as subliminal depolarization waveforms. During the recording time of 300 seconds, the number of miniature excitatory postsynaptic potentials recorded in the ipsilateral hippocampus following fluid percussion injury was significantly decreased by the application of diazepam (P < 0.05; Figure 3). These results showed that, in the ipsilateral rat hippocampus CA1 area following fluid percussion injury, diazepam effectively reversed the increase in spontaneous glutamate release from the Schaffer collateral terminals.


Effects of diazepam on glutamatergic synaptic transmission in the hippocampal CA1 area of rats with traumatic brain injury.

Cao L, Bie X, Huo S, Du J, Liu L, Song W - Neural Regen Res (2014)

Effect of diazepam (DZ) on the miniature excitatory postsynaptic potentials (mEPSPs) in rat hippocampal CA1 pyramidal neurons following fluid percussion injury (FPI).The number in the brackets represents the number of rats. There were 19 and 12 pyramidal neurons in FPI and FPI + DZ groups, respectively. Quantitative data were expressed as the mean ± SD and analyzed by one-way analysis of variance. Student-Newman-Keuls tests were used for specific comparisons. *P < 0.05, vs. FPI group.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4281428&req=5

Figure 3: Effect of diazepam (DZ) on the miniature excitatory postsynaptic potentials (mEPSPs) in rat hippocampal CA1 pyramidal neurons following fluid percussion injury (FPI).The number in the brackets represents the number of rats. There were 19 and 12 pyramidal neurons in FPI and FPI + DZ groups, respectively. Quantitative data were expressed as the mean ± SD and analyzed by one-way analysis of variance. Student-Newman-Keuls tests were used for specific comparisons. *P < 0.05, vs. FPI group.
Mentions: To investigate a possible contribution of postsynaptic mechanisms in this enhancement, we analyzed the number of miniature excitatory postsynaptic potentials. Under the experimental conditions, the spontaneous miniature excitatory postsynaptic potentials were recorded as subliminal depolarization waveforms. During the recording time of 300 seconds, the number of miniature excitatory postsynaptic potentials recorded in the ipsilateral hippocampus following fluid percussion injury was significantly decreased by the application of diazepam (P < 0.05; Figure 3). These results showed that, in the ipsilateral rat hippocampus CA1 area following fluid percussion injury, diazepam effectively reversed the increase in spontaneous glutamate release from the Schaffer collateral terminals.

Bottom Line: Diazepam significantly decreased the numbers of spikes evoked by super stimuli in the presence of 15 μmol/L bicuculline, indicating the existence of inhibitory pathways in the injured rat hippocampus.Diazepam effectively increased the paired-pulse facilitation ratio in the hippocampal CA1 region following fluid percussion injury, reduced miniature excitatory postsynaptic potentials, decreased action-potential-dependent glutamine release, and reversed spontaneous glutamine release.These data suggest that diazepam could decrease the fluid percussion injury-induced enhancement of excitatory synaptic transmission in the rat hippocampal CA1 area.

View Article: PubMed Central - PubMed

Affiliation: Department of Functional Neurosurgery, Xi'an Red Cross Hospital, Xi'an, Shaanxi Province, China ; Department of Rehabilitation Medicine, Xuanwu Hospital, Capital Medical University, Beijing, China.

ABSTRACT
The activity of the Schaffer collaterals of hippocampal CA3 neurons and hippocampal CA1 neurons has been shown to increase after fluid percussion injury. Diazepam can inhibit the hyperexcitability of rat hippocampal neurons after injury, but the mechanism by which it affects excitatory synaptic transmission remains poorly understood. Our results showed that diazepam treatment significantly increased the slope of input-output curves in rat neurons after fluid percussion injury. Diazepam significantly decreased the numbers of spikes evoked by super stimuli in the presence of 15 μmol/L bicuculline, indicating the existence of inhibitory pathways in the injured rat hippocampus. Diazepam effectively increased the paired-pulse facilitation ratio in the hippocampal CA1 region following fluid percussion injury, reduced miniature excitatory postsynaptic potentials, decreased action-potential-dependent glutamine release, and reversed spontaneous glutamine release. These data suggest that diazepam could decrease the fluid percussion injury-induced enhancement of excitatory synaptic transmission in the rat hippocampal CA1 area.

No MeSH data available.


Related in: MedlinePlus