DOI: 10.5061/dryad.3xsj3txdc
title: Cyclic guanosine monophosphate modulates locomotor acceleration induced by nitric oxide but not serotonin in Clione limacina central pattern generator swim interneurons

description: Typically, the marine mollusk, Clione limacina, exhibits a slow, hovering
 locomotor gait to maintain its position in the water column. 
 However, the animal exhibits behaviorally relevant locomotor swim
 acceleration during escape response and feeding behavior.  Both
 nitric oxide and serotonin mediate this behavioral swim
 acceleration.  In this study, we examine the role that the second
 messenger, cGMP, plays in mediating nitric oxide and serotonin induced
 swim acceleration.  We observed that application of an analogue
 of cGMP or an activator of soluble guanylyl cyclase, increased fictive
 locomotor speed recorded from Pd-7 interneurons of the animal’s locomotor
 central pattern generator. Moreover, inhibition of soluble guanylyl
 cyclase decreased fictive locomotor speed.  These results suggest
 that basal levels of cGMP are important for slow swimming and that
 increased production of cGMP mediates swim acceleration in
 Clione.  Because nitric oxide has its effect through cGMP
 signaling and because we show herein that cGMP produces cellular changes
 in Clione swim interneurons that are consistent to cellular changes
 produced by serotonin application, we hypothesize that both nitric oxide
 and serotonin function via a common signal transduction pathway that
 involves cGMP.  Our results show that cGMP mediates nitric
 oxide-induced but not serotonin-induced swim acceleration in Clione.
description: Data collected represent intracellular recordings from Pd-7
 interneurons of the <em>Clione</em>
 <em>limacina</em> locomotor central pattern generator using
 Axon Instruments Axoclamp 2B or A-M Systems amplifiers with
 thin-walled borosilicate glass microelectrodes filled with 2 M potassium
 acetate.  Data are representative of recordings made using Axon
 Instruments, Inc. Axoscope software or Pclamp software and A/D converter
 connected to a PC computer.  Action potential frequency (an indication of
 fictive swim frequency), action potential duration, and sag potential
 amplitude were measured in control conditions and after application of
 pharmacological agents (drugs that affect nitric oxide signaling and cGMP
 signaling). Statistical analysis of the mean control values to mean
 experimental values are compared and was done using GraphPad Instat
 (GraphPad Software, La Jolla, CA, USA).
description: The following is a summary
 of the data set components. <b><i>Supplement 1
 Fig. 1 Effect of 8-Br-cGMP on Fictive Swim
 Frequency</i></b> This Excel file summarizes the
 data showing how 8-Br-cGMP changes fictive swim frequency recorded from
 Pd-7 swim interneurons of the <i>Clione</i> swim central
 pattern generator.  The first sheet summarizes all of the data used in
 this figure, including statistical results.  Subsequent sheets show the
 individual data for these experiments. <b><i>Supplement 2
 Fig. 2 Effect of ODQ + NO on Fictive Swim
 Frequency</i></b> This Excel file summarizes the
 data showing that ODQ, an inhibitor of soluble guanylyl cyclase, prevents
 nitric oxide from causing an acceleration in fictive swim frequency
 recorded from Pd-7 swim interneurons of the <i>Clione</i> swim
 central pattern generator.  The first sheet summarizes all of the data
 used in this figure, including statistical results.  Subsequent sheets
 show the individual data for these experiments. <b><i>Supplement 3
 Fig. 3 Effect of 8-Br-cGMP on Action Potential
 Duration</i></b> This Excel file summarizes the
 data showing how 8-Br-cGMP changes the action potential duration recorded
 from Pd-7 swim interneurons of the <i>Clione</i> swim central
 pattern generator.  <b><i>Supplement 4
 Fig. 4 Effect of 8-Br-cGMP on Baseline
 Depolarization</i></b> This Excel file includes the data
 showing how 8-Br-cGMP results in baseline depolarization recorded from
 Pd-7 swim interneurons of the <i>Clione</i> swim central
 pattern generator (column A is time in seconds and column B is mV for each
 sheet).  <b><i>Supplement 5
 Fig. 5 Sag Amplitude Analysis</i></b> This Excel file summarizes the
 data showing how 8-Br-cGMP changes the sag potential amplitude recorded
 from Pd-7 swim interneurons of the <i>Clione</i> swim central
 pattern generator.  The first sheet summarizes all of the data used in
 this figure, including statistical results.  Subsequent sheets show the
 individual data for these experiments. <b><i>Supplement 6
 Fig. 6 Effects of ODQ + 5HT on Fictive Swim Frequency
 </i></b> This Excel file summarizes the
 data showing that ODQ, an inhibitor of soluble guanylyl cyclase, does not
 prevent serotonin from causing an acceleration in fictive swim frequency
 recorded from Pd-7 swim interneurons of the <i>Clione</i> swim
 central pattern generator.  The first sheet summarizes all of the data
 used in this figure, including statistical results.  Subsequent sheets
 show the individual data for these experiments (column A is time in
 seconds and column B is mV). <b><i>Supplement 7
 Fig. 7 Effect of PKG Inhibtor (Rp-8-Br-PET-cGMP) + 5HT on Fictive Swim
 Frequency</i></b> This Excel file summarizes the
 data showing that Rp-8-Br-PET-cGMP, an inhibitor of cGMP dependent protein
 kinase (PKG), does not prevent serotonin from causing an acceleration in
 fictive swim frequency recorded from Pd-7 swim interneurons of the
 <i>Clione</i> swim central pattern generator.  The first sheet
 summarizes all of the data used in this figure, including statistical
 results.  Subsequent sheets show the individual data for these experiments
 (column A is time in seconds and column B is mV). Additional Data
 includes: LNAME
 PTIO 5HT data show that serotonin increases fictive swimming speed
 independent of nitric oxide. DEANO NO donor data that show
 that nitric oxide increases fictive swimming speed independent of
 serotonin. Isoliquiritigenin