State-changes in the swimmeret system: a neural circuit that drives locomotion
| Autor: | Wendy M. Hall, Brian Mulloney, Naranzogt Tschuluun |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Patch-Clamp Techniques
Carbachol Physiology Nerve net Voltage clamp Stimulation Astacoidea Cholinergic Agonists Aquatic Science Neurotransmission Biology Synaptic Transmission medicine Animals Magnesium Patch clamp Octopamine Molecular Biology Ecology Evolution Behavior and Systematics Motor Neurons Motor neuron Ganglia Invertebrate medicine.anatomical_structure nervous system Insect Science Cholinergic Calcium Animal Science and Zoology Nerve Net Adrenergic alpha-Agonists Neuroscience Locomotion Research Article medicine.drug |
| Zdroj: | Journal of Experimental Biology. 212:3605-3611 |
| ISSN: | 1477-9145 0022-0949 |
| DOI: | 10.1242/jeb.033621 |
| Popis: | SUMMARYThe crayfish swimmeret system undergoes transitions between a silent state and an active state. In the silent state, no patterned firing occurs in swimmeret motor neurons. In the active state, bursts of spikes in power stroke motor neurons alternate periodically with bursts of spikes in return stroke motor neurons. In preparations of the isolated crayfish central nervous system(CNS), the temporal structures of motor patterns expressed in the active state are similar to those expressed by the intact animal. These transitions can occur spontaneously, in response to stimulation of command neurons, or in response to application of neuromodulators and transmitter analogues. We used single-electrode voltage clamp of power-stroke exciter and return-stroke exciter motor neurons to study changes in membrane currents during spontaneous transitions and during transitions caused by bath-application of carbachol or octopamine (OA). Spontaneous transitions from silence to activity were marked by the appearance of a standing inward current and periodic outward currents in both types of motor neurons. Bath-application of carbachol also led to the development of these currents and activation of the system. Using low Ca2+–high Mg2+ saline to block synaptic transmission, we found that the carbachol-induced inward current included a direct response by the motor neuron and an indirect component. Spontaneous transitions from activity to silence were marked by disappearance of the standing inward current and the periodic outward currents. Bath-application of OA led promptly to the disappearance of both currents, and silenced the system. OA also acted directly on both types of motor neurons to cause a hyperpolarizing outward current that would contribute to silencing the system. |
| Databáze: | OpenAIRE |
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