The calcium sensor synaptotagmin 1 is expressed and regulated in hippocampal postsynaptic spines

TY - JOUR

T1 - The calcium sensor synaptotagmin 1 is expressed and regulated in hippocampal postsynaptic spines

AU - Hussain, Suleman

AU - Egbenya, Daniel Lawer

AU - Lai, Yi-Chen

AU - Dosa, Zita J

AU - Sørensen, Jakob B

AU - Anderson, Anne E

AU - Davanger, Svend

N1 - © 2017 Wiley Periodicals, Inc.

PY - 2017/11

Y1 - 2017/11

N2 - Synaptotagmin 1 is a presynaptic calcium sensor, regulating SNARE-mediated vesicle exocytosis of transmitter. Increasing evidence indicate roles of SNARE proteins in postsynaptic glutamate receptor trafficking. However, a possible postsynaptic expression of synaptotagmin 1 has not been demonstrated previously. Here, we used postembedding immunogold electron microscopy to determine the subsynaptic localization of synaptotagmin 1 in rat hippocampal CA1 Schaffer collateral synapses. We report for the first time that synaptotagmin 1 is present in rat hippocampal postsynaptic spines, both on cytoplasmic vesicles and at the postsynaptic density. We further investigated whether postsynaptic synaptotagmin 1 is regulated during synaptic plasticity. In a rat model of chronic temporal lobe epilepsy, we found that presynaptic and postsynaptic concentrations of the protein are reduced compared to control animals. This downregulation may possibly be an adaptive measure to decrease both presynaptic and postsynaptic calcium sensitivity in excitotoxic conditions.

AB - Synaptotagmin 1 is a presynaptic calcium sensor, regulating SNARE-mediated vesicle exocytosis of transmitter. Increasing evidence indicate roles of SNARE proteins in postsynaptic glutamate receptor trafficking. However, a possible postsynaptic expression of synaptotagmin 1 has not been demonstrated previously. Here, we used postembedding immunogold electron microscopy to determine the subsynaptic localization of synaptotagmin 1 in rat hippocampal CA1 Schaffer collateral synapses. We report for the first time that synaptotagmin 1 is present in rat hippocampal postsynaptic spines, both on cytoplasmic vesicles and at the postsynaptic density. We further investigated whether postsynaptic synaptotagmin 1 is regulated during synaptic plasticity. In a rat model of chronic temporal lobe epilepsy, we found that presynaptic and postsynaptic concentrations of the protein are reduced compared to control animals. This downregulation may possibly be an adaptive measure to decrease both presynaptic and postsynaptic calcium sensitivity in excitotoxic conditions.

U2 - 10.1002/hipo.22761

DO - 10.1002/hipo.22761

M3 - Journal article

C2 - 28686803

SN - 1050-9631

VL - 27

SP - 1168

EP - 1177

JO - Hippocampus

JF - Hippocampus

IS - 11

ER -