Neurons communicate with each other in the brain through specialized junctions, called synapses. During brain development, numerous new synapses are established and new synapses continue to form throughout life. The long-term goal of the research proposed in this application is to determine the molecular basis of synapse formation in the vertebrate brain. The first proteins have now been identified that organize synapse formation and development. One such protein is SynCAM 1, a synaptic cell adhesion molecule that connects pre- and postsynaptic sides. Importantly, SynCAM 1 induces the formation of new, fully functional excitatory synapses between neurons. It is highly expressed in the developing brain during intense synaptogenesis, indicating a broad function for this molecule in synapse formation. Such synaptogenic functions have been validated in cultured neurons and in vivo. The objective of this application is to define the signaling pathways through which SynCAM 1 organizes synapses and determine how other trans-synaptic proteins act in concert with it. The central hypothesis of this application is that SynCAM signaling organizes developing synapses and regulates synaptic function at later stages. To attain the objective of this application, three specific aims will be pursued.
The first aim of this application is to determine the intracellular signaling pathways through which SynCAM 1- mediated synaptic adhesion instructs synapse development, focusing on changes in the synaptic cytoskeleton. Second, it will be analyzed how trans-synaptic interactions act in concert to assemble synapses and shape their structure. Third, it will be determined to which extent SynCAM 1 functions in vivo together with other synaptic adhesion molecules to organize synapses. These experiments involve the biochemical characterization of SynCAM binding partners and their activities. Functional analyses of SynCAM interactions will be performed by quantitative immunocytochemistry, imaging of synapses in cultured hippocampal neurons, and electrophysiological recordings. In addition, the in vivo relevance of these interactions will be tested using structural and functional studies of synapses, including ultrastructural analyses, electrophysiological recordings, and behavioral analyses. Achieving these goals is important for human health, as altered synapse organization affects the wiring of neuronal circuits and synaptic plasticity. These changes are associated with alterations in human behavior, the ability to learn and remember, and addiction to drugs of abuse. Furthermore, deficits of synapse formation likely underlie neurodevelopmental disorders such as autism. In summary, this application aims to identify the molecular interactions involved in synapse formation. The progress under this application will allow testing to which extent these synapse-organizing processes are affected in disorders of the human brain and whether they represent novel points of therapeutic intervention.
Nerve cells communicate with each other in the brain through specialized junctions, called synapses. These junctions form in the human brain soon before birth, and changes in this process impair the wiring of the brain and can cause mental retardation. This research program is relevant to public health because it will analyze how nerve cells connect to each other in the healthy brain, allowing us to understand what steps go wrong in developmental disorders.
|Park, Kellie A; Ribic, Adema; Laage Gaupp, Fabian M et al. (2016) Excitatory Synaptic Drive and Feedforward Inhibition in the Hippocampal CA3 Circuit Are Regulated by SynCAM 1. J Neurosci 36:7464-75|
|Perez de Arce, Karen; Schrod, Nikolas; Metzbower, Sarah W R et al. (2015) Topographic Mapping of the Synaptic Cleft into Adhesive Nanodomains. Neuron 88:1165-72|
|Cheadle, Lucas; Biederer, Thomas (2014) Activity-dependent regulation of dendritic complexity by semaphorin 3A through Farp1. J Neurosci 34:7999-8009|
|Ribic, Adema; Liu, Xinran; Crair, Michael C et al. (2014) Structural organization and function of mouse photoreceptor ribbon synapses involve the immunoglobulin protein synaptic cell adhesion molecule 1. J Comp Neurol 522:900-20|
|Giza, Joanna I; Jung, Yonwoo; Jeffrey, Rachel A et al. (2013) The synaptic adhesion molecule SynCAM 1 contributes to cocaine effects on synapse structure and psychostimulant behavior. Neuropsychopharmacology 38:628-38|
|Park, Kellie; Biederer, Thomas (2013) Neuronal adhesion and synapse organization in recovery after brain injury. Future Neurol 8:555-567|
|Cheadle, Lucas; Biederer, Thomas (2012) The novel synaptogenic protein Farp1 links postsynaptic cytoskeletal dynamics and transsynaptic organization. J Cell Biol 199:985-1001|
|Missler, Markus; SÃ¼dhof, Thomas C; Biederer, Thomas (2012) Synaptic cell adhesion. Cold Spring Harb Perspect Biol 4:a005694|
|Wilke, Scott A; Hall, Benjamin J; Antonios, Joseph K et al. (2012) NeuroD2 regulates the development of hippocampal mossy fiber synapses. Neural Dev 7:9|
|Sandau, Ursula S; Mungenast, Alison E; McCarthy, Jack et al. (2011) The synaptic cell adhesion molecule, SynCAM1, mediates astrocyte-to-astrocyte and astrocyte-to-GnRH neuron adhesiveness in the mouse hypothalamus. Endocrinology 152:2353-63|
Showing the most recent 10 out of 23 publications