Function unable to retrive spike_shape data from Spike shape function (M)

In the following code I am trying to enable my function to retrive spike-shape data that are the results of another function called M. However, for an unknown reason it doesnt read that function and cannot retrive those data to go to the next steps of the code: See below please: I get errors like the following:

Unrecognized field name "maxAmpASamp".

Error in Fig_RN_Shape_v4 (line 82)

AHPSamp(h) = M(h).maxAmpASamp; % calculation based on Fig_LC code

maxAmpASamp and the rest are present in M.

function [A,ampDCList,FilesNotFound,STATS,as,alme] = Fig_RN_Shape_v4

S = RNDataStruct;
ampDCList = [0.5 1 2 3];
nCols = 1;
nucleusCode = 'RN';
getSpikeWaveforms = 1;
doPlot = 1;
fs = 30e3;
preTime = -5e-3;
postTime = 10e-3;
preSamp = round(preTime*fs);
postSamp = round(postTime*fs);
sampVec = [preSamp:postSamp];
tvec = sampVec/fs;

%%
nAmps = length(ampDCList);
for n = 1:nAmps
    eval(['A.A' num2str(n) '= [];'])
end
FilesNotFound = [];
i=1;
ii = 0;
for n = 1:length(S)
    if S(n).isSpikedSorted == 1;
        for m = 1:length(S(n).fileListDC)
            dataFolder = [S(n).dataPath S(n).fileListDC{m}];
            nChans = S(n).nChans;
            dataFolder = unixCheckPath(dataFolder);
            phyFolder = [dataFolder filesep 'continuous_filt' filesep 'continuous_filt.GUI'];
            % get the cluster Info FileName
            clusterInfoFileName = [phyFolder filesep 'cluster_info.tsv'];
            if exist(clusterInfoFileName, 'file')
                phySpikeFile = [dataFolder '\' S(n).fileListDC{m} '.physpks'];
                if exist(phySpikeFile, 'file')
                    disp(['Loading ' phySpikeFile])
                    load(phySpikeFile,'-mat')
                else
                    I = getPhySpikeTimes(dataFolder,getSpikeWaveforms,nChans);
                    disp(['Saving ' phySpikeFile])
                    save(phySpikeFile,"I")
                end
                M = struct();
                for o = 1:length(I)
                    ii = ii + 1;
                    if isfield(I(o), 'avgSpike')  % Check within the current element I(o)
                        avgSpike = I(o).avgSpike - min(I(o).avgSpike);
                        avgSpike = avgSpike / max(avgSpike);  
                        M(ii) = quantifySpikeWaveform(I(o).avgSpike, I(o).tvec, doPlot);
                    end
                end
                
                if ~isempty(I)
                    I = analysePhySpikeTimes(I,0);
                    for h = 1:length(I)
                        I(h).ratName = S(n).ratName;
                        I(h).ratNumber = str2num(I(h).ratName(4:5));
                    end
                    A.A1 = I; %% arbitrary
                    if ~isnan(I(1).ampDC)
                        indAmp = find(I(1).ampDC(1) == ampDCList);
                        if ~isempty(indAmp)
                            eval(['A.A' num2str(indAmp) '= [A.A' num2str(indAmp) ' I];'])
                        end
                    end
                end
            else
                FilesNotFound{i} = clusterInfoFileName;
                i = i + 1;
            end
        end
    end
end
%%

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%5HT-Neurons-Filtering
filteredNeurons = [];
B = A.A1;
for h = 1:length(B)
    AHPSamp(h) = M(h).maxAmpASamp; % calculation based on Fig_LC code
    TroughSamp(h) = M(h).minAmpSamp; % calculation based on Fig_LC code
    TroughAHPDur(h) = M(h).tvec(AHPSamp(h)) - M(h).tvec(TroughSamp(h)); % calculation based on Fig_LC code
    if B(h).spikeRatePreMean >= 1 && B(h).spikeRatePreMean <= 5
        if B(h).spikeRateDurMean >= 1 && B(h).spikeRateDurMean <= 5
            if B(h).spikeRatePostMean >= 1 && B(h).spikeRatePostMean <= 5
                if TroughAHPDur(h)*1e3 >= 1 % I am not certain whether TroughAHPDur(h)*1e3 gives spike duration in ms; please double-check
                    filteredNeurons = [filteredNeurons B(h)];
                end
            end
        end
    end
end
A.A1 = filteredNeurons;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

[Alireza Majdi]

quantifySpikeWaveform code

[Walter Roberson]

Please read http://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval for information about why we strongly recommend against creating variable names dynamically.