Activity induced changes in the distribution of Shanks at hippocampal synapses

• Published in: Neuroscience 2010-06, Vol.168 (1), p.11-17
• Main Authors: Tao-Cheng, J.H, Dosemeci, A, Gallant, P.E, Smith, C, Reese, T
• Format: Article
• Language: English
• Subjects: Adaptor Proteins, Signal Transducing - metabolism; Animals; Antibodies; Biological and medical sciences; Calcium - metabolism; Cells, Cultured; Dendritic Spines - metabolism; Fundamental and applied biological sciences. Psychology; Hippocampus - metabolism; Male; Membrane Proteins - metabolism; Mice; Mice, Inbred C57BL; Nerve Tissue Proteins - metabolism; Neurology; Neurons - metabolism; Protein Transport; Rats; Rats, Sprague-Dawley; Synapses - metabolism; Vertebrates: nervous system and sense organs
• ISSN: 0306-4522; 1873-7544
• DOI: 10.1016/j.neuroscience.2010.03.041

Abstract Dendritic spines contain a family of abundant scaffolding proteins known as Shanks, but little is known about how their distributions might change during synaptic activity. Here, pre-embedding immunogold electron microscopy is used to localize Shanks in synapses from cultured hippocampal neurons. We find that Shanks are preferentially located at postsynaptic densities (PSDs) as well as in a filamentous network near the PSD, extending up to 120 nm from the postsynaptic membrane. Application of sub-type specific antibodies shows that Shank2 is typically concentrated at and near PSDs while Shank1 is, in addition, distributed throughout the spine head. Depolarization with high K+ for 2 min causes transient, reversible translocation of Shanks towards the PSD that is dependent on extracellular Ca2+ . The amount of activity-induced redistribution and subsequent recovery is pronounced for Shank1 but less so for Shank2. Thus, Shank1 appears to be a dynamic element within the spine, whose translocation could be involved in activity-induced, transient structural changes, while Shank2 appears to be a more stable element positioned at the interface of the PSD with the spine cytoplasm.