Paired turbulence and light effect on calcium increase in Hermissenda (Blackwell 2004)

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Accession:53427
The sea slug Hermissenda learns to associate light and hair cell stimulation, but not when the stimuli are temporally uncorrelated...These issues were addressed using a multi-compartmental computer model of phototransduction, calcium dynamics, and ionic currents of the Hermissenda photoreceptor...simulations show that a potassium leak channel, which closes with an increase in calcium, is required to produce both the untrained LLD and the enhanced LLD due to the decrease in voltage dependent potassium currents.
Reference:
1 . Blackwell KT (2004) Paired turbulence and light do not produce a supralinear calcium increase in Hermissenda. J Comput Neurosci 17:81-99 [PubMed]
Model Information (Click on a link to find other models with that property)
Model Type: Neuron or other electrically excitable cell; Electrogenic pump;
Brain Region(s)/Organism:
Cell Type(s): Hermissenda photoreceptor Type B;
Channel(s): I A; I K,leak; I h; I K,Ca; I Sodium; I Calcium; I Potassium;
Gap Junctions:
Receptor(s): GabaA; GabaB; IP3;
Gene(s):
Transmitter(s): Gaba;
Simulation Environment: Chemesis;
Model Concept(s): Temporal Pattern Generation; Invertebrate; Signaling pathways; Calcium dynamics;
Implementer(s): Blackwell, Avrama [avrama at gmu.edu];
Search NeuronDB for information about:  GabaA; GabaB; IP3; I A; I K,leak; I h; I K,Ca; I Sodium; I Calcium; I Potassium; Gaba;
//CHEMESIS2.0
//pumpsoma-axon5.g
/* include current to compartment to decrease hyperpolarization
 * initialized ncx with lower V to decrease total ncx effect
 * increase cytleak by 2% */
/* model of phototransduction at level of stochastic activation of rhodopsin
** and mass action enzyme reactions from G protein activation
** to ip3 production.  Includes calcium release and light induced Na current.
*/

include bcell-const.g
include rxn-func.g
include comp-func.g
include changerad.g
include cicr-func.g
include ryan-func.g
include iicrflux-func.g
include cytpump-func.g
include cal-ip3-2D.g
include cal-ip3-rhab.g
include cal-ip3-taper.g
include volt-func-shunt.g
include kleak-newlig2.g
include phototrans2.g
include yamoah-ih.g
include ica.g
include kc4act1.g
include ka.g
include lgt-na17.g
include gabaa-chan.g
include gabab-syn.g
include gabab-chan.g

int i, j
Vinit	=	-60.0
gshunt	=	0.005
float kncx = 1.5e-3
float Vncx = 1400
float kpmca = 0.3e-3
float Vpmca = 1.6e-11
float Vpmcarhab = 0
float Vncxrhab = 0
int pmca_power =	1
maxcicr	=	0.16
serca   =	0.00094
axondiama = 3e-4
axondiamb = 5e-4
str plctype="mm"
lightdelay=2000
str filepath="/export/home/avrama/chemesis2.0/ncx/results/"

echo "reading in model"

include taperncxcell.g
phototrans /rhab/ip3s1
lgtna_comp /rhab/vm /rhab/ip3s2 {rhabcyls} {gna}

echo "initializing output file"
str gaba="/branch_syn/vm[2]"
include small-output.g
//include whole-output.g
//include ip3whole-output.g

reset
setcytpumpleak /soma/Cacyts1 /extracell {somacyls} {Vpmca} {kpmca} {Vncx} {kncx}
setcytpumpleak /rhab/Cacyts1 /extracell {rhabcyls} {Vpmcarhab} {kpmca} {Vncxrhab} {kncx}
setcytpumpleak /neck/Cacyts1 /extracell 1 {Vpmcarhab} {kpmca} {Vncxrhab} {kncx}
setcytpumpleak /axon/Cacyts1 /extracell {axoncyls} {Vpmcarhab} {kpmca} {Vncxrhab} {kncx}
setcytpumpleak /branch/Cacyts1 /extracell {branchcyls} {Vpmcarhab} {kpmca} {Vncxrhab} {kncx}
setcytpumpleak /branch_syn/Cacyts1 /extracell {branchcyls} {Vpmcarhab} {kpmca} {Vncxrhab} {kncx}
//check

/* loop for paired stimuli
   start GABA at 1000 or 3000, start light at 2000, stop at 5000 msec */
int stop=5000/0.005
int isi, start

  for (isi=-1000; isi<=1000; isi=isi+2000)
    start=lightdelay+isi
    echo "isi=" {isi} "start=" {start} "stop=" {stop}
    setfield /stat/spike_rate peak 0.15 tau_fall 1000 decay_type 0 delay {start}

     str filenam = (filepath)@"pumpsoma-axon5"@(isi/1000)@".dat"
     setfield /output/plot_out filename {filenam} initialize 1 append 0 leave_open 1

     str filenam = (filepath)@"pumpsoma-axon5"@(isi/1000)@".cal"
     setfield /output/spatial filename {filenam} initialize 1 append 0 leave_open 1
     str filenam = (filepath)@"pumpsoma-axon5"@(isi/1000)@".ip3"
     setfield /output/ip3 filename {filenam} initialize 1 append 0 leave_open 1

     reset
     step {stop}
     setfield /stat/spike_rate peak 0
     step 1600000 
end

/* light alone */
    setfield /stat/spike_rate peak 0.0 tau_fall 1000 decay_type 0 delay 16000

     str filenam = (filepath)@"pumpsoma-axon5-light.dat"
     setfield /output/plot_out filename {filenam} initialize 1 append 0 leave_open 1

     str filenam = (filepath)@"pumpsoma-axon5-light.cal"
     setfield /output/spatial filename {filenam} initialize 1 append 0 leave_open 1
     str filenam = (filepath)@"pumpsoma-axon5-light.ip3"
     setfield /output/ip3 filename {filenam} initialize 1 append 0 leave_open 1


     reset
     step 1000000
     step 2400000 

/* GABA alone */
    setfield /stat/spike_rate peak 0.15 tau_fall 1000 decay_type 0 delay 1000
    setfield /rhabmemb/shutter level1 0 delay1 16000 width1 0

     str filenam = (filepath)@"pumpsoma-axon5-gaba.dat"
     setfield /output/plot_out filename {filenam} initialize 1 append 0 leave_open 1

     str filenam = (filepath)@"pumpsoma-axon5-gaba.cal"
     setfield /output/spatial filename {filenam} initialize 1 append 0 leave_open 1
     str filenam = (filepath)@"pumpsoma-axon5-gaba.ip3"
     setfield /output/ip3 filename {filenam} initialize 1 append 0 leave_open 1

     reset
     step {stop}
     setfield /stat/spike_rate peak 0
     step 1600000 

delete /output/ip3 

/* decrease Gbar of vdep K currents: Kca and Ka, to evaluate effect of 
learning.  Only due light alone stimulil */
float oldgka, oldgkca, oldcap, oldcat

oldgka={getfield /soma/vm[1]/ka Gbar}
setfield /soma/vm[1]/ka Gbar {oldgka*0.7}
echo oldgka={oldgka}
showfield /soma/vm[1]/ka Gbar

for (i=1; i<=somacyls; i=i+1)
	oldgkca={getfield /soma/Cacyts1[{i}]/kc Gbar}
	echo oldgkca={oldgkca}
	setfield /soma/Cacyts1[{i}]/kc Gbar {oldgkca*0.7}
	showfield /soma/Cacyts1[{i}]/kc Gbar
end

/* light alone */
    setfield /rhabmemb/shutter level1 {intensity} delay1 {lightdelay} width1 {duration}
    setfield /stat/spike_rate peak 0.0 tau_fall 1000 decay_type 0 delay 16000

     str filenam = (filepath)@"pumpsoma-vdepk70-light.dat"
     setfield /output/plot_out filename {filenam} initialize 1 append 0 leave_open 1

     str filenam = (filepath)@"pumpsoma-vdepk70-light.cal"
     setfield /output/spatial filename {filenam} initialize 1 append 0 leave_open 1

     reset
     step 1000000
     step 2400000 

/*add in change in just one calcium current*/
for (i=1; i<=somacyls; i=i+1)
	showfield /soma/Cacyts1[{i}]/persist_ghk_ica Pca
	oldcap={getfield /soma/Cacyts1[{i}]/persist_ghk_ica Pca}
	setfield /soma/Cacyts1[{i}]/persist_ghk_ica Pca {oldcap*0.7}
	showfield /soma/Cacyts1[{i}]/persist_ghk_ica Pca

end

    setfield /stat/spike_rate peak 0.0 tau_fall 1000 decay_type 0 delay 26000

     str filenam = (filepath)@"pumpsoma-cap70-light.dat"
     setfield /output/plot_out filename {filenam} initialize 1 append 0 leave_open 1

     str filenam = (filepath)@"pumpsoma-cap70-light.cal"
     setfield /output/spatial filename {filenam} initialize 1 append 0 leave_open 1

     reset
     step 1000000
     step 2400000 

/* add in change in transient calcium currents */
for (i=1; i<=somacyls; i=i+1)

	showfield /soma/Cacyts1[{i}]/trans_ghk_ica Pca
	oldcat={getfield /soma/Cacyts1[{i}]/trans_ghk_ica Pca}
	setfield /soma/Cacyts1[{i}]/trans_ghk_ica Pca {oldcat*0.7}
	showfield /soma/Cacyts1[{i}]/trans_ghk_ica Pca
end

    setfield /stat/spike_rate peak 0.0 tau_fall 1000 decay_type 0 delay 26000

     str filenam = (filepath)@"pumpsoma-allvdep70-light.dat"
     setfield /output/plot_out filename {filenam} initialize 1 append 0 leave_open 1

     str filenam = (filepath)@"pumpsoma-allvdep70-light.cal"
     setfield /output/spatial filename {filenam} initialize 1 append 0 leave_open 1

     reset
     step 1000000
     step 2400000 








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