Muscles innervated by a single motor neuron exhibit divergent synaptic properties on multiple time scales
| Autor: | Amy E. Pritchard, Andrew T. Wakefield, John K. Latimer, Dawn M. Blitz |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Male
0301 basic medicine Brachyura Physiology Neuromuscular Junction Aquatic Science Biology Summation 03 medical and health sciences Bursting 0302 clinical medicine Postsynaptic potential Stomatogastric nervous system Motor system medicine Animals Molecular Biology Ecology Evolution Behavior and Systematics Motor Neurons Muscles Central pattern generator Motor neuron Ganglia Invertebrate 030104 developmental biology medicine.anatomical_structure Insect Science Synapses Animal Science and Zoology Neuron Neuroscience 030217 neurology & neurosurgery Muscle Contraction |
| Zdroj: | Journal of Experimental Biology. |
| ISSN: | 1477-9145 0022-0949 |
| DOI: | 10.1242/jeb.148908 |
| Popis: | Adaptive changes in the output of neural circuits underlying rhythmic behaviors are relayed to muscles via motor neuron activity. Pre- and postsynaptic properties of neuromuscular junctions can impact the transformation from motor neuron activity to muscle response. Further, synaptic plasticity occurring on the time scale of inter-spike intervals can differ between multiple muscles innervated by the same motor neuron. In rhythmic behaviors, motor neuron bursts can elicit additional synaptic plasticity. However, it is unknown if plasticity regulated by the longer time scale of inter-burst intervals also differs between synapses from the same neuron, and whether any such distinctions occur across a physiological activity range. To address these issues, we measured electrical responses in muscles innervated by a chewing circuit neuron, the lateral gastric (LG) motor neuron, in a well-characterized small motor system, the stomatogastric nervous system (STNS) of the Jonah crab, Cancer borealis. In vitro and in vivo, sensory, hormonal and modulatory inputs elicit LG bursting consisting of inter-spike intervals of 50-250 ms and inter-burst intervals of 2-24 s. Muscles expressed similar facilitation measured with paired stimuli except at the shortest inter-spike interval. However distinct decay time constants resulted in differences in temporal summation. In response to bursting activity, augmentation occurred to different extents and saturated at different inter-burst intervals in the three muscles. Further, augmentation interacted with facilitation, resulting in distinct intra-burst facilitation between muscles. Thus, responses of multiple target muscles diverge across a physiological activity range due to distinct synaptic properties sensitive to multiple time scales. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|