The transient potassium outward current has different roles in modulating the pyloric and gastric mill rhythms in the stomatogastric ganglion.
The crustacean stomatogastric nervous system is a classic model for understanding the effects of modulating ionic currents and synapses at both the cell and network levels. The stomatogastric ganglion in this system contains two distinct central pattern generators: a slow gastric mill network that generates flexible rhythmic outputs (8-20 s) and is often silent, and a fast pyloric network that generates more consistent rhythmic outputs (0.5-2 s) and is always active in vitro. Different ionic conductances contribute to the properties of individual neurons and therefore to the overall dynamics of the pyloric and gastric mill networks. However, the contributions of ionic currents to different dynamics between the pyloric and gastric mill networks are not well understood. The goal of this study is to evaluate how changes in outward potassium current (IA) in the stomatogastric ganglion affect the dynamics of the pyloric and gastric mill rhythms by interfering with normal IAactivity. We bath-applied the specific IAblocker 4-aminopyridine to reduce IA's effect in the stomatogastric ganglion in vitro and evaluated quantitatively the changes in both rhythms. We found that blocking IAin the stomatogastric ganglion alters the synchronization between pyloric neurons, and consistently activates the gastric mill rhythm in quiescent preparations.
Department of Biology, Northeastern University, Boston, MA, 02115, USA. zhu.li@husky.neu.edu.
Lin
L
Zhu
Marine Science Center, Department of Marine and Environmental Sciences, Northeastern University, Nahant, MA, 01908, USA.
Allen I
AI
Selverston
Department of Biology, Northeastern University, Boston, MA, 02115, USA.|Marine Science Center, Department of Marine and Environmental Sciences, Northeastern University, Nahant, MA, 01908, USA.
Joseph
J
Ayers
D015761:4-Aminopyridine / Q000494:pharmacology; D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D001703:Biophysics; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D005260:Female; D005583:Fourier Analysis; D017952:Ganglia, Invertebrate / Q000166:cytology*; D000070559:Gizzard, Non-avian / Q000187:drug effects / Q000502:physiology*; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D033521:Palinuridae; D018408:Patch-Clamp Techniques; D010507:Periodicity; D011188:Potassium / Q000378:metabolism*; D026902:Potassium Channel Blockers / Q000494:pharmacology; D011708:Pylorus / Q000187:drug effects / Q000502:physiology*
D026902:Potassium Channel Blockers; D015761:4-Aminopyridine; D011188:Potassium
Central pattern generator; Dynamics; I A; Stomatogastric