TY - JOUR
T1 - Search for a two-input model for future investigations of 'synaptic tagging' in freely moving animals in vivo
AU - Hassan, Hadir
AU - Frey, Sabine
AU - Frey, Julietta U.
N1 - Funding Information:
This work was supported by the Volkswagenstiftung AZ: I/07922 to JUF.
PY - 2006/4/15
Y1 - 2006/4/15
N2 - Processes of "synaptic tagging" guarantee synaptic input specificity after the induction of a protein synthesis-dependent late long-term potentiation (late-LTP). Distinct high-frequency stimulation can set a transient "synaptic tag" at the activated synapses, which captures plasticity-related proteins (PRPs) synthesized synapse-non-specifically in dendritic branches/compartments or the somata. Thus, only those synapses, which expressed a "tag", are also able to express late-LTP. Additionally, it was shown that the synthesis of PRPs is triggered by heterosynaptic, non-glutamatergic requirements during LTP-induction in tissue from adult animals. All these experiments were performed in hippocampal slices in vitro so far. Two questions now arise: first, is it possible to describe processes of 'synaptic tagging' in the intact, freely moving animal and second, is the stimulation of glutamatergic inputs sufficient to induce 'tagging' or is the co-activation of a modulatory-heterosynaptic input, also required for the process? We have first developed a technique, which allows us now to induce distinct forms of LTP at the ipsilateral CA1 site by specifically stimulating glutamatergic hippocampal structures at the contralateral site in the intact, freely moving rat. Thus, the used stimulation protocol allowed us to activate two separate synaptic inputs to the same neuronal stimulation, a pre-requisite for tagging-experiments to be investigated in vivo.
AB - Processes of "synaptic tagging" guarantee synaptic input specificity after the induction of a protein synthesis-dependent late long-term potentiation (late-LTP). Distinct high-frequency stimulation can set a transient "synaptic tag" at the activated synapses, which captures plasticity-related proteins (PRPs) synthesized synapse-non-specifically in dendritic branches/compartments or the somata. Thus, only those synapses, which expressed a "tag", are also able to express late-LTP. Additionally, it was shown that the synthesis of PRPs is triggered by heterosynaptic, non-glutamatergic requirements during LTP-induction in tissue from adult animals. All these experiments were performed in hippocampal slices in vitro so far. Two questions now arise: first, is it possible to describe processes of 'synaptic tagging' in the intact, freely moving animal and second, is the stimulation of glutamatergic inputs sufficient to induce 'tagging' or is the co-activation of a modulatory-heterosynaptic input, also required for the process? We have first developed a technique, which allows us now to induce distinct forms of LTP at the ipsilateral CA1 site by specifically stimulating glutamatergic hippocampal structures at the contralateral site in the intact, freely moving rat. Thus, the used stimulation protocol allowed us to activate two separate synaptic inputs to the same neuronal stimulation, a pre-requisite for tagging-experiments to be investigated in vivo.
KW - Contralateral CA1
KW - Contralateral CA3
KW - Hippocampus
KW - In vivo
KW - Ipsilateral CA1
KW - Late-LTP
KW - Long-term potentiation
KW - Two-input model
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U2 - 10.1016/j.jneumeth.2005.09.005
DO - 10.1016/j.jneumeth.2005.09.005
M3 - Article
C2 - 16216335
AN - SCOPUS:33644781682
SN - 0165-0270
VL - 152
SP - 220
EP - 228
JO - Journal of Neuroscience Methods
JF - Journal of Neuroscience Methods
IS - 1-2
ER -