How BK and SK channels benefit early vision (Li X et al 2019)

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Accession:263042
"Ca2+-activated K+ channels (BK and SK) are ubiquitous in synaptic circuits, but their role in network adaptation and sensory perception remains largely unknown. Using electrophysiological and behavioral assays and biophysical modeling, we discover how visual information transfer in mutants lacking the BK channel (dSlo- ), SK channel (dSK- ), or both (dSK- ;; dSlo- ) is shaped in the female fruit fly (Drosophila melanogaster) R1-R6 photoreceptor-LMC circuits (R-LMC-R system) through synaptic feedforward-feedback interactions and reduced R1-R6 Shaker and Shab K+ conductances. This homeostatic compensation is specific for each mutant, leading to distinctive adaptive dynamics. We show how these dynamics inescapably increase the energy cost of information and promote the mutants' distorted motion perception, determining the true price and limits of chronic homeostatic compensation in an in vivo genetic animal model. These results reveal why Ca2+-activated K+ channels reduce network excitability (energetics), improving neural adaptability for transmitting and perceiving sensory information. ..."
Reference:
1 . Li X, Abou Tayoun A, Song Z, Dau A, Rien D, Jaciuch D, Dongre S, Blanchard F, Nikolaev A, Zheng L, Bollepalli MK, Chu B, Hardie RC, Dolph PJ, Juusola M (2019) Ca2+-Activated K+ Channels Reduce Network Excitability, Improving Adaptability and Energetics for Transmitting and Perceiving Sensory Information. J Neurosci 39:7132-7154 [PubMed]
Model Information (Click on a link to find other models with that property)
Model Type: Synapse;
Brain Region(s)/Organism: Drosophila;
Cell Type(s):
Channel(s): I Potassium; I K,Ca;
Gap Junctions:
Receptor(s):
Gene(s):
Transmitter(s):
Simulation Environment:
Model Concept(s): Information transfer; Invertebrate; Homeostasis;
Implementer(s):
Search NeuronDB for information about:  I K,Ca; I Potassium;
%% This is the main function to do dynamic clamp to differnt SK mutant fly photoreceptors, 
%% during the naturalistic stimuli. 

%% This program calls DynamicClampIter to calculate Isyn
%% and all the K+ current. Then it calculates the ATP that is consumed during the naturalistic 
%% stimuli pattern

%% Input: datasource saves the photoreceptor's intracellular's recordings; param is the parameter for the 
%% Hodgkin Huxley model 

%datasource = 'SKSlo4Vol_All'
%datasource = 'SKVol';
%datasource = 'WTVol';
%datasource = 'sloVol'

%% The parameters used in roger's clamp data

%WT
% param =  [RestPos{1,2}+correct_restvol 20  -57.1  0  -85  4*0.085e-3   0 0 -5 0   2.4e-3   5e-3     0.11e-3 ]; 

% Skslo
% param =  [RestPos{4,2}+correct_restvol 20  -57.1  0  -85  4*0.085e-3  0 0 -5 0   2.4e-3   0.85*5e-3     0.11e-3 ]; 

% Sk
% param =  [-65  20  -57.1  0  -85  4*0.085e-3   0 0 -5 0   0.6*2.4e-3    0.6*5e-3     0.11e-3 ];

% slo
% %param =  [-65  20  -57.1  0  -85  4*0.085e-3   0 0 -5 0   0.8*2.4e-3   0.65*5e-3     0.11e-3 ];



%% the parameters used for Table 1. 
% WT
%param = [-65   1  -57.1  0  -85    0.85e-3  0  0   -5   0    2.4e-3   5e-3   0.11e-3 0];

% SKSlo
% param = [-65   1  -57.1  0  -85    0.85e-3  0  0   -5   0    2.4e-3  0.85*5e-3   0.11e-3 0];  

% SK
% param =  [-65  1  -57.1   0  -85  0.85e-3      0 0 -5 0   0.6*2.4e-3    0.6*5e-3     0.11e-3 ];

% Slo
% param =  [-65  1  -57.1  0  -85  0.85e-3      0 0 -5 0   0.8*2.4e-3   0.65*5e-3     0.11e-3 ];


function  DynamicClamp_Isyn_NoCl(datasource,param)

load(datasource)

% WTVol are the selected NS mean responses for different WT photoreceptors.
% the slected data are in the folder /Users/zhuoyisong/MATLAB/SK-Zhuoyi/DynamicConductance_Feedback/newOct2017/DynamicClamp_Diana_NS/NS_EXP_Diana/WT
wt_rest = -57; sk_rest = -47.45; slo18_rest = -46; SKslo18_rest = -41;
RestPos = cell(4,2);
RestPos{1,1} = 'wt';RestPos{2,1} = 'sk';RestPos{3,1} = 'slo18';RestPos{4,1} = 'SKslo18';
RestPos{1,2} = wt_rest; RestPos{2,2} = sk_rest; RestPos{3,2} = slo18_rest; RestPos{4,2} = SKslo18_rest;

eval(['VolEXP = ' datasource ';']);
%VolEXP = SKSlo4Vol_All;
%VolEXP = WTVol;
%VolEXP = SKVol;
%VolEXP = sloVol;

correct_restvol = 0; % a parameter to correct the resting potential for the experimental data
samprate        = 1000;

VolSim = []; IK =[]; IShaker=[];  IShab=[];  INew=[];  ICleak=[]; 
ICl = []; ILeak=[]; ATP_m = [];ATPk_m = []; ATPcl_m = [];ATP_simon_m = [];
ISyn = [];

for gg = 1:size(VolEXP,2)


TT = 980;

Vol_exp = VolEXP(1:TT,gg);

load NS_xf_BG105_MacroC
II = mean(NS_xf_BG105_MacroC,2)*0.001;
I = II(length(II)-TT+1:end);

Isyn = zeros(size(I));
gsyn = zeros(size(I));
gsynm = 0;

samprate = 1000;

[t, y, Isyn,Ishaker,Ishab,Ileak,Inew,Icleak,Icl]= DynamicClampGoodIter(I, param, samprate,Vol_exp);

%figure(1);hold all; plot(t,y(:,1));plot(t,Vol_exp); title('Voltage');xlabel('ms'); ylabel('mV');
%figure(2); plot(Isyn); title('LIC'); xlabel('ms'); ylabel('nA');

Vol = y(:,1);
Ik = Ishaker + Ishab + Inew + Ileak;

VolSim = [VolSim, Vol]; IK =[IK,Ik]; IShaker=[IShaker,Ishaker];  
IShab=[IShab,Ishab];  INew=[INew,Inew];  ICleak=[ICleak,Icleak]; 
ICl = [ICl,Icl]; ILeak=[ILeak,Ileak]; ISyn = [ISyn,Isyn];

timelength = length(I)/samprate; 
% here outward current is positive, Icl is positive outward currrent, Cl
% in, K out
Ip = 0.5*(Ishaker + Ishab + Inew + Ileak - I*0.0086*0.001) - 0.25*(Icl+Icleak); 
Ipk = 0.5*(Ishaker + Ishab + Inew + Ileak - I*0.0086*0.001);
Ipcl = -0.25*(Icl+Icleak); % the K extruded out by Na-K-Cl cotranspoter, does not require ATP

%To increase stability, 10^(-12) is multiplied to NA
NA = 6.02*10^(11);   % avacado constant, 6.02*10^23/mol
F = 96485;           % farady constant, C/mol
Ip_s = 201; Ip_e = length(I);
ATP = sum(Ip)*NA/F/(timelength)

Isimon = I+Isyn+Icl;
ATP_simon = (1/3)*(sum(Isimon))*NA/F/(timelength)

ATP_m = [ATP_m,ATP];
ATP_simon_m = [ATP_simon_m,ATP_simon];

figure;
subplot(2,2,1);hold all;
plot(t,Vol_exp);plot(t,y(:,1));
title('Voltage');xlabel('ms'); ylabel('mV');axis([1,TT,-110,-0]);
legend('experiment','simulation');
text(200,-80,['ATP ' num2str(ATP, '%10.5e\n')])
text(200,-90,['ATP simon ' num2str(ATP_simon, '%10.5e\n')])
 
subplot(2,2,2);hold all;
hold all;plot(Isyn,'k');plot(I,'b');
title('Isyn vs. LIC');xlabel('Time (ms)'); ylabel('Current (nA)');
legend('Isyn','LIC');

subplot(2,2,3);hold all;
plot(Ishaker,'b');plot(Ishab,'r');plot(Inew,'k');
title('K+ currents');xlabel('Time (ms)'); ylabel('Current (nA)');
legend('shaker','shab','new');

subplot(2,2,4);hold all;
plot(Ileak,'b');plot(Icleak);plot(Icl);
title('leak currents');xlabel('Time (ms)'); ylabel('Current (nA)');
legend('K leak','Cl leak','Icl','Location','east');

end

% SaveDataFile = [datasource '_ATP_NSDynamicClamp_0Cl_wtC'];
% save(SaveDataFile,'param','VolEXP','VolSim', 'ISyn', 'ICleak', 'ICl', 'IShaker',...
%     'IShab', 'INew', 'ILeak', 'ATP_m', 'ATP_simon_m');


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