March 19, 2013 @ 11:00 AM – 12:00 PM
Center for the Neurobiology of Learning and Memory (CNLM) Colloquium
Aryeh Routtenberg, Ph.D.
Department of Physiology
Northwestern University
A Novel View of Synaptic Tagging:Regulation of presynaptic terminal plasticity
Terminal-specific and behavior-selective presynaptic structural plasticity has been linked to long-term memory (McGonigal, R. et al., Hippocampus, 2012). Hippocampal granule cell axon (mossy fibers, MF) terminals specifically identified by an antibody to zinc transporter 3 (ZnT3), were counted from confocal z-stacks in the stratum lucidum and stratum oriens. In hidden platform, but not visible platform, trained rats there was a significant increase in the number of large MF terminals (LMTs) in SO but surprisingly, there was no detectable increase in small MF terminals (SMTs). Importantly, LMTs synapse on CA3 pyramidal neurons, while SMTs target inhibitory interneurons. Learning may thus enhance CA3 pyramidal neuron throughput. Because this same learning elevates Wnt signaling with a parallel time course as the presynaptic remodeling we have studied, using hippocampal cells in culture (Tabatadze, N. et al., Hippocampus, 2012) the activity-dependent elevation of Wnt7 which retrogradely regulate presynaptic active zones and thus presynaptic plasticity. The present findings highlight the pivotal role in memory of presynaptic structural and molecular plasticity in information storage.
Tuesday, March 19, 2013
11 a.m.
All colloquia are held in the Dale Melbourne Herklotz Conference Center, CNLM.