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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

Position of the electrodes. Photomicrographs of Nissl-stained hippocampal slices show placement of electrodes (white arrowheads) in mf-CA3 and AC–CA3 preparations: (i) shows the position of the stimulation electrode in the mossy fiber pathway and (ii) the position of the recording electrode in area CA3 stratum lucidum, whereas picture (iii) shows the stimulating electrode in the associational-commissural pathway and (iv) the recording electrode in area CA3 stratum radiatum.
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Figure 1: Position of the electrodes. Photomicrographs of Nissl-stained hippocampal slices show placement of electrodes (white arrowheads) in mf-CA3 and AC–CA3 preparations: (i) shows the position of the stimulation electrode in the mossy fiber pathway and (ii) the position of the recording electrode in area CA3 stratum lucidum, whereas picture (iii) shows the stimulating electrode in the associational-commissural pathway and (iv) the recording electrode in area CA3 stratum radiatum.

Mentions: Seven- to eight- week old male Wistar rats (Charles River, Germany) were anaesthetized (Pentobarbital, 52 mg/kg, intraperitoneally) and underwent chronic implantation of hippocampal electrodes and a guide cannula, as described previously (Manahan-Vaughan, 1997; Hagena and Manahan-Vaughan, 2011), using coordinates based on the rat brain atlas from Paxinos and Watson (1986). Briefly, for mf-CA3 implantations, the recording electrode was placed above the CA3 pyramidal layer of the dorsal hippocampus, 3.2 mm posterior to bregma and 2.2 mm lateral to midline. The bipolar stimulation electrode was implanted 3.5 mm posterior to bregma and 2.0 mm lateral to midline (Figure 1). For commissural/associational (AC)- CA3 implantations, the recording electrode was placed 3.1 mm posterior tor bregma and 4.2 mm lateral to midline (Figure 1). To verify the correct positions of the electrodes, test pulses were applied to evoke field potentials during the implantation procedure, and postmortem histological analysis was also performed (Bock, 1989; Manahan-Vaughan et al., 1998).


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)

Position of the electrodes. Photomicrographs of Nissl-stained hippocampal slices show placement of electrodes (white arrowheads) in mf-CA3 and AC–CA3 preparations: (i) shows the position of the stimulation electrode in the mossy fiber pathway and (ii) the position of the recording electrode in area CA3 stratum lucidum, whereas picture (iii) shows the stimulating electrode in the associational-commissural pathway and (iv) the recording electrode in area CA3 stratum radiatum.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 1: Position of the electrodes. Photomicrographs of Nissl-stained hippocampal slices show placement of electrodes (white arrowheads) in mf-CA3 and AC–CA3 preparations: (i) shows the position of the stimulation electrode in the mossy fiber pathway and (ii) the position of the recording electrode in area CA3 stratum lucidum, whereas picture (iii) shows the stimulating electrode in the associational-commissural pathway and (iv) the recording electrode in area CA3 stratum radiatum.
Mentions: Seven- to eight- week old male Wistar rats (Charles River, Germany) were anaesthetized (Pentobarbital, 52 mg/kg, intraperitoneally) and underwent chronic implantation of hippocampal electrodes and a guide cannula, as described previously (Manahan-Vaughan, 1997; Hagena and Manahan-Vaughan, 2011), using coordinates based on the rat brain atlas from Paxinos and Watson (1986). Briefly, for mf-CA3 implantations, the recording electrode was placed above the CA3 pyramidal layer of the dorsal hippocampus, 3.2 mm posterior to bregma and 2.2 mm lateral to midline. The bipolar stimulation electrode was implanted 3.5 mm posterior to bregma and 2.0 mm lateral to midline (Figure 1). For commissural/associational (AC)- CA3 implantations, the recording electrode was placed 3.1 mm posterior tor bregma and 4.2 mm lateral to midline (Figure 1). To verify the correct positions of the electrodes, test pulses were applied to evoke field potentials during the implantation procedure, and postmortem histological analysis was also performed (Bock, 1989; Manahan-Vaughan et al., 1998).

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