The ability of the mammalian brain to undergo long-lasting, activity-dependent changes in synaptic function and structure importantly contributes to the neural circuit modifications that underlie many forms of adaptive and pathological experience-dependent plasticity, including learning and memory. A leading model for such synaptic plasticity is NMDA receptor-dependent long-term potentiation (LTP). Although progress has been made in understanding the mechanisms underlying LTP, much remains unknown. This proposal tests the novel hypothesis that postsynaptic complexins play a mandatory role in the trafficking of AMPA receptors to the plasma membrane during LTP and also in the growth of dendritic spines that accompanies LTP. Complexins are critical for the calcium-dependent regulation of transmitter release via direct interactions with the SNARE proteins that are required for presynaptic vesicle fusion. This project will perform experiments that for the first time examine the synaptic functions of postsynaptic complexin. The experiments use a """"""""molecular replacement"""""""" strategy, which incorporates the simultaneous, viral-mediated expression of multiple shRNAs to knockdown complexin levels as well as express a """"""""replacement"""""""" version of wildtype or mutant complexin in single hippocampal pyramidal cells in vivo or in vitro. Electrophysiological assays in acute hippocampal slices and cell biological assays in cultured neurons will be performed to determine the consequences of the complexin manipulations on basal synaptic responses, LTP, long-term depression and AMPA receptor exocytosis and endocytosis. The role of postsynaptic complexin on the spine growth that accompanies LTP will also be examined. These experiments will elucidate novel molecular mechanisms by which excitatory synapses in the mammalian brain are likely modified during various forms of experience-dependent plasticity, including learning and memory. The results will also open up new, innovative areas of research on the postsynaptic membrane trafficking underlying LTP. In addition, this research will provide information that is critical for the development of agents that modify synaptic transmission in ways that promote cognitive function and alleviate psychiatric symptoms.
Learning and memory involves long-lasting modification of the communication between nerve cells at their physical connections, which are termed synapses. This project will use sophisticated experimental techniques to elucidate some of the key molecular mechanisms underlying how this modification happens. The information that will be collected is essential for developing more effective treatments for the deterioration of cognitive function that accompanies many forms of mental illness.
|Soler-Llavina, Gilberto J; Arstikaitis, Pamela; Morishita, Wade et al. (2013) Leucine-rich repeat transmembrane proteins are essential for maintenance of long-term potentiation. Neuron 79:439-46|
|Jurado, Sandra; Goswami, Debanjan; Zhang, Yingsha et al. (2013) LTP requires a unique postsynaptic SNARE fusion machinery. Neuron 77:542-58|
|Ahmad, Mohiuddin; Polepalli, Jai S; Goswami, Debanjan et al. (2012) Postsynaptic complexin controls AMPA receptor exocytosis during LTP. Neuron 73:260-7|
|Selcher, Joel C; Xu, Weifeng; Hanson, Jesse E et al. (2012) Glutamate receptor subunit GluA1 is necessary for long-term potentiation and synapse unsilencing, but not long-term depression in mouse hippocampus. Brain Res 1435:8-14|
|Yu, Wendou; Polepalli, Jai; Wagh, Dhananjay et al. (2012) A critical role for the PAR-1/MARK-tau axis in mediating the toxic effects of A? on synapses and dendritic spines. Hum Mol Genet 21:1384-90|
|Jurado, Sandra; Biou, Virginie; Malenka, Robert C (2010) A calcineurin/AKAP complex is required for NMDA receptor-dependent long-term depression. Nat Neurosci 13:1053-5|
|Citri, Ami; Bhattacharyya, Samarjit; Ma, Cong et al. (2010) Calcium binding to PICK1 is essential for the intracellular retention of AMPA receptors underlying long-term depression. J Neurosci 30:16437-52|
|Citri, Ami; Soler-Llavina, Gilberto; Bhattacharyya, Samarjit et al. (2009) N-methyl-D-aspartate receptor- and metabotropic glutamate receptor-dependent long-term depression are differentially regulated by the ubiquitin-proteasome system. Eur J Neurosci 30:1443-50|
|Bhattacharyya, Samarjit; Biou, Virginie; Xu, Weifeng et al. (2009) A critical role for PSD-95/AKAP interactions in endocytosis of synaptic AMPA receptors. Nat Neurosci 12:172-81|
|Xu, Weifeng; Schluter, Oliver M; Steiner, Pascal et al. (2008) Molecular dissociation of the role of PSD-95 in regulating synaptic strength and LTD. Neuron 57:248-62|
Showing the most recent 10 out of 21 publications