Neuroscience 2005 Abstract
| Presentation Number: | 752.13 |
|---|---|
| Abstract Title: | Different central pattern generators elicit similar gastric mill rhythms. |
| Authors: |
Hertzberg, S. R.*1
; Nusbaum, M. P.1
1Dept Neurosci, Univ. of Pennsylvania, Philadelphia, PA |
| Primary Theme and Topics |
Sensory and Motor Systems - Pattern Generation and Locomotion -- Invertebrate pattern generation |
| Secondary Theme and Topics | Sensory and Motor Systems<br />- Invertebrate Sensory and Motor Systems<br />-- Invertebrate motor systems |
| Session: |
752. Invertebrate Pattern Generation II Poster |
| Presentation Time: | Tuesday, November 15, 2005 1:00 PM-2:00 PM |
| Location: | Washington Convention Center - Hall A-C, Board # DD25 |
| Keywords: | stomatogastric, neuromodulation, network, neuropeptide |
Neuromodulation commonly enables one CPG circuit to generate many different activity patterns. We have found a counter-example while characterizing the actions of the neuropeptide pyrokinin (PK) on the gastric mill (chewing: cycle period ~10s) and pyloric (filtering chewed food: cycle period ~1s) motor circuits in the stomatogastric ganglion (STG) of the crab Cancer borealis. PK (10 -6 M) superfusion to the isolated STG activates a gastric mill rhythm (GMR) that is very similar to the one elicited by selective stimulation of the projection neuron MCN1 (Hertzberg et al., SFN Abstr 33:604.14). This occurs despite the facts that MCN1 neither exhibits PK-like immunolabeling nor requires PK to elicit this rhythm. Moreover, MCN1 releases its cotransmitters rhythmically in the STG (Nusbaum et al., TINS 2001) while PK is tonically present in the bath. Despite the similarity in the evoked GMRs, and the inclusion of the reciprocally inhibitory pattern generator neurons Int1 and LG in both rhythms, MCN1 (Bartos et al., 1999 JNeurosci) and PK use distinct mechanisms to activate this rhythm. For example, the pyloric pacemaker neuron AB regulates both of these GMRs in comparable ways, but its activity is necessary only for the PK-elicited GMR. As a result, LG burst initiation involves an escape from inhibition-type mechanism during the MCN1-GMR while there is no escape, but only a post-inhibitory rebound-type mechanism during PK application. Another difference is that the gastric mill neuron DG effectively inhibits the LG neuron, and thus acts as a CPG neuron, only during PK application. Despite the similarity of these two GMRs, their influence on the pyloric rhythm is distinct. Specifically, the MCN1-elicited GMR regulates the speed and intensity of the pyloric rhythm (Bartos and Nusbaum, J Neurosci 1997) but the PK-elicited GMR has no effect on this rhythm. We aim to fully document the underlying, distinct cellular mechanisms whereby different modulatory inputs can elicit comparable rhythms from related but distinct central pattern generating circuits.
Supported by NIH NS29436 (MPN)
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2005 Neuroscience Meeting Planner. Washington, DC: Society for Neuroscience, 2005. Online.
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