Neuroscience 2004 Abstract
| Presentation Number: | 657.1 |
|---|---|
| Abstract Title: | Pevpyrokinin elicits a MCN1-like gastric mill rhythm using different cellular mechanisms. |
| Authors: |
Hertzberg, S. R.*1
; Nusbaum, M. P.1
1Dept Neurosci, Univ Pennsylvania Sch. of Med., Philadelphia, PA |
| Primary Theme and Topics |
Motor Systems - Pattern Generation and Locomotion |
| Secondary Theme and Topics | Motor Systems<br />- Invertebrate Motor Systems |
| Session: |
657. Modulation of Small Circuit Dynamics Poster |
| Presentation Time: | Tuesday, October 26, 2004 8:00 AM-9:00 AM |
| Location: | San Diego Convention Center - Hall A-H, Board # GG16 |
| Keywords: | central pattern generator, motor control, invertebrate, neuromodulation |
Neuromodulation commonly enables one neuronal circuit to generate many different activity patterns. We have found a counter-example while characterizing the actions of the neuropeptide pevpyrokinin (PPK) on the gastric mill (chewing) and pyloric (filtering chewed food) motor circuits in the stomatogastric ganglion (STG) of the crab Cancer borealis. Superfusion of PPK1 (10-6M) to the isolated STG activates a gastric mill rhythm (GMR) that is nearly identical to the one elicited by selective stimulation of the identified projection neuron MCN1 (Hertzberg et al., SFN Abstr 33:604.14). This occurs despite the facts that MCN1 neither exhibits PPK-like immunolabeling nor requires PPK to elicit this rhythm, and PPK application does not activate MCN1. Moreover, MCN1 releases its cotransmitters rhythmically in the STG while PPK is tonically present in the bath. Despite the similarity in the evoked GMRs, MCN1 (Bartos et al., 1999 JNeurosci) and PPK1 use distinct mechanisms to activate this rhythm. For example, the pyloric rhythm regulates both of these GMRs in comparable ways, but its activity is necessary only for the PPK-elicited GMR. As a result, the pyloric pacemaker neuron AB acts as a gastric mill pattern generator neuron for the latter GMR. Another difference is that the gastric mill pattern generator neuron LG generates plateau potentials as well as endogenous rhythmic bursts only in the presence of PPK. Finally, the gastric mill rhythm regulates the speed of the pyloric rhythm during the MCN1-elicited rhythm (Bartos and Nusbaum, 1997 JNeurosci), but not in the PPK-elicited rhythm. We aim to fully document the ability and underlying distinct mechanisms whereby different modulatory inputs can elicit comparable rhythms from the same neuronal circuit.
Supported by NIH NS29436 (MPN).
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2004 Neuroscience Meeting Planner. San Diego, CA: Society for Neuroscience, 2004. Online.
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