Short-Term Synaptic Plasticity in Central Pattern Generators

Short-term synaptic plasticity (STP) is a transient (milliseconds to minutes) activity-dependent change in the amplitude (strength) of the postsynaptic current in response to presynaptic activity. It has clear implications for neural signaling and has been studied for several decades. Much of the modeling work has focused on the events in the presynaptic terminal and primarily on the role of Ca in of neurotransmitters (Zucker & Regehr ; Fioravante and Regehr 2+ synaptic release 2002 ). However, postsynaptic effects such as saturation of can also contribute to STP (Hennig 2011 postsynaptic receptors ; Xu-Friedman and Regehr ). A complete understanding of short-term synaptic plasticity requires knowing how 2013 2004 the preand postsynaptic neurons interact to alter synaptic strength. The contribution of short-term synaptic plasticity to network-level output has probably been best examined in studies of networks. CPG networks produce rhythmic patterned outputs without patterned input and central pattern generator (CPG) are best understood in the analysis of rhythmic motor activities such as locomotion and respiration. For instance, the CPG underlying the inspiratory phase of respiration is located in the found within the ventrolateral pre-Bötzinger complex medulla of the mammalian brain (Grillner ). Identified CPG circuits are known to govern locomotion in invertebrates, 2003 including , mollusks, and crustaceans (Arshavsky Yu et al. ; Ayers ; Friesen and Kristan ). leeches 1993 2004 2007 Additionally, locomotion in mammals is believed to be governed by CPG networks in the spinal cord (MacKay-Lyons 2002 ). The understanding of CPGs in producing motor behaviors has been greatly advanced through the use of computational (Butera et al. ; Tabak et al. ; Oh et al. ; Vavoulis et al. ; Sherwood et al. ). models 1999 200