x1 = loadspk('yam22669_10DIV_nodrug_01.spk');
x2 = loadspk('yam22669_10DIV_drugs_01.spk');
x3 = loadspk('yam22669_12DIV_wash6_01.spk');
x4 = loadspk('yam22669_12DIV_wash6_02.spk');

time = [x1.time-max(x1.time); x2.time; x3.time+max(x2.time); x4.time+max(x2.time)+max(x3.time)];
channel = [x1.channel; x2.channel; x3.channel; x4.channel];
unit = [x1.unit; x2.unit; x3.unit; x4.unit];

timestamps = [0 max(x2.time)];

save yam22669_10-12DIV time channel unit timestamps;