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Differentiation in the protein synthesis-dependency of persistent synaptic plasticity in mossy fiber and associational/commissural CA3 synapses in vivo.

Hagena H, Manahan-Vaughan D - Front Integr Neurosci (2013)

Bottom Line: In contrast, at AC-CA3 synapses, translation inhibitors prevented intermediate/late-LTP and late-LTD only.Transcription effects were also synapse-specific: whereas transcription inhibitors inhibited late-LTP and late-LTD (>3 h) at mf-CA3 synapses, at AC-CA3 synapses, protein transcription affected early-LTP and late-LTD.These results show that the AC-CA3 and mf-CA3 synapses display different properties in terms of their protein synthesis dependency, suggesting different roles in the processing of short- and long term synaptic plasticity.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurophysiology, Medical Faculty, Ruhr University Bochum Bochum, Germany ; International Graduate School for Neuroscience, Ruhr University Bochum Bochum, Germany.

ABSTRACT
Long-term potentiation (LTP) and long-term depression (LTD) are two mechanisms involved in the long-term storage of information in hippocampal synapses. In the hippocampal CA1 region, the late phases of LTP and LTD are protein-synthesis dependent. In the dentate gyrus, late-LTP but not LTD requires protein synthesis. The protein synthesis-dependency of persistent plasticity at CA3 synapses has not yet been characterized. Here, the roles of protein transcription and translation at mossy fiber (mf) and associational/commissural (AC)- synapses were studied in freely behaving rats. In control animals, low-frequency stimulation (LFS) evoked robust LTD (>24 h), whereas high-frequency stimulation (HFS) elicited robust LTP (>24 h) at both mf-CA3 and AC-CA3 synapses. Translation inhibitors prevented early and late phases of LTP and LTD at mf-CA3 synapses. In contrast, at AC-CA3 synapses, translation inhibitors prevented intermediate/late-LTP and late-LTD only. Transcription effects were also synapse-specific: whereas transcription inhibitors inhibited late-LTP and late-LTD (>3 h) at mf-CA3 synapses, at AC-CA3 synapses, protein transcription affected early-LTP and late-LTD. These results show that the AC-CA3 and mf-CA3 synapses display different properties in terms of their protein synthesis dependency, suggesting different roles in the processing of short- and long term synaptic plasticity.

No MeSH data available.


Related in: MedlinePlus

Application of translational- and transcriptional-Inhibitors do not alter basal synaptic transmission. (A) After injection of anisomycin (4.8 μg), emetine (240 μg), actinomycin D (72 μg) or DRB (20 nM), fEPSPs recorded during test-pulse stimulation showed stable responses for over 24 h. Line breaks indicate change in time scale. (B) Analog traces recorded during test-pulse experiments show fEPSP responses 5 min pre-injection (left traces), 5 min post-injection (middle traces) and 24 h after injection (right traces), in the anisomycin experiment (upper left), in the emetine experiment (lower left), in the actinomycin D experiment (upper right), and in the DRB experiment (lower right). Vertical scale bar: 2 mV, horizontal scale bar: 8 ms.
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Figure 6: Application of translational- and transcriptional-Inhibitors do not alter basal synaptic transmission. (A) After injection of anisomycin (4.8 μg), emetine (240 μg), actinomycin D (72 μg) or DRB (20 nM), fEPSPs recorded during test-pulse stimulation showed stable responses for over 24 h. Line breaks indicate change in time scale. (B) Analog traces recorded during test-pulse experiments show fEPSP responses 5 min pre-injection (left traces), 5 min post-injection (middle traces) and 24 h after injection (right traces), in the anisomycin experiment (upper left), in the emetine experiment (lower left), in the actinomycin D experiment (upper right), and in the DRB experiment (lower right). Vertical scale bar: 2 mV, horizontal scale bar: 8 ms.

Mentions: To assess, whether protein synthesis inhibitors affect basal synaptic transmission in mf-CA3 synapses, in the concentrations used here, the translation inhibitors, anisomycin or emetine, and the transcription inhibitors, actinomycin D or DRB, were applied in an experiment in which animals received only test-pulse stimulation. Here, no effects on the evoked potentials were observed over the 24 monitoring period [ANOVA, F(4, 13) = 0.64; p = 0.64; n = 7, Figures 6A,B].


Differentiation in the protein synthesis-dependency of persistent synaptic plasticity in mossy fiber and associational/commissural CA3 synapses in vivo.

Hagena H, Manahan-Vaughan D - Front Integr Neurosci (2013)

Application of translational- and transcriptional-Inhibitors do not alter basal synaptic transmission. (A) After injection of anisomycin (4.8 μg), emetine (240 μg), actinomycin D (72 μg) or DRB (20 nM), fEPSPs recorded during test-pulse stimulation showed stable responses for over 24 h. Line breaks indicate change in time scale. (B) Analog traces recorded during test-pulse experiments show fEPSP responses 5 min pre-injection (left traces), 5 min post-injection (middle traces) and 24 h after injection (right traces), in the anisomycin experiment (upper left), in the emetine experiment (lower left), in the actinomycin D experiment (upper right), and in the DRB experiment (lower right). Vertical scale bar: 2 mV, horizontal scale bar: 8 ms.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3585440&req=5

Figure 6: Application of translational- and transcriptional-Inhibitors do not alter basal synaptic transmission. (A) After injection of anisomycin (4.8 μg), emetine (240 μg), actinomycin D (72 μg) or DRB (20 nM), fEPSPs recorded during test-pulse stimulation showed stable responses for over 24 h. Line breaks indicate change in time scale. (B) Analog traces recorded during test-pulse experiments show fEPSP responses 5 min pre-injection (left traces), 5 min post-injection (middle traces) and 24 h after injection (right traces), in the anisomycin experiment (upper left), in the emetine experiment (lower left), in the actinomycin D experiment (upper right), and in the DRB experiment (lower right). Vertical scale bar: 2 mV, horizontal scale bar: 8 ms.
Mentions: To assess, whether protein synthesis inhibitors affect basal synaptic transmission in mf-CA3 synapses, in the concentrations used here, the translation inhibitors, anisomycin or emetine, and the transcription inhibitors, actinomycin D or DRB, were applied in an experiment in which animals received only test-pulse stimulation. Here, no effects on the evoked potentials were observed over the 24 monitoring period [ANOVA, F(4, 13) = 0.64; p = 0.64; n = 7, Figures 6A,B].

Bottom Line: In contrast, at AC-CA3 synapses, translation inhibitors prevented intermediate/late-LTP and late-LTD only.Transcription effects were also synapse-specific: whereas transcription inhibitors inhibited late-LTP and late-LTD (>3 h) at mf-CA3 synapses, at AC-CA3 synapses, protein transcription affected early-LTP and late-LTD.These results show that the AC-CA3 and mf-CA3 synapses display different properties in terms of their protein synthesis dependency, suggesting different roles in the processing of short- and long term synaptic plasticity.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurophysiology, Medical Faculty, Ruhr University Bochum Bochum, Germany ; International Graduate School for Neuroscience, Ruhr University Bochum Bochum, Germany.

ABSTRACT
Long-term potentiation (LTP) and long-term depression (LTD) are two mechanisms involved in the long-term storage of information in hippocampal synapses. In the hippocampal CA1 region, the late phases of LTP and LTD are protein-synthesis dependent. In the dentate gyrus, late-LTP but not LTD requires protein synthesis. The protein synthesis-dependency of persistent plasticity at CA3 synapses has not yet been characterized. Here, the roles of protein transcription and translation at mossy fiber (mf) and associational/commissural (AC)- synapses were studied in freely behaving rats. In control animals, low-frequency stimulation (LFS) evoked robust LTD (>24 h), whereas high-frequency stimulation (HFS) elicited robust LTP (>24 h) at both mf-CA3 and AC-CA3 synapses. Translation inhibitors prevented early and late phases of LTP and LTD at mf-CA3 synapses. In contrast, at AC-CA3 synapses, translation inhibitors prevented intermediate/late-LTP and late-LTD only. Transcription effects were also synapse-specific: whereas transcription inhibitors inhibited late-LTP and late-LTD (>3 h) at mf-CA3 synapses, at AC-CA3 synapses, protein transcription affected early-LTP and late-LTD. These results show that the AC-CA3 and mf-CA3 synapses display different properties in terms of their protein synthesis dependency, suggesting different roles in the processing of short- and long term synaptic plasticity.

No MeSH data available.


Related in: MedlinePlus