# compute firing rate
f(x)=x^2+I
wiener w
I'=0
init x=-10
count'=0
x'=f(x)+sig*w
global 1 x-xspike {x=xreset;count=count+1}
par xreset=-10,sig=.2,xspike=10
aux fr=count/5000
@ total=5000,meth=euler,bound=10000,trans=4999.99
@ xp=I,yp=fr,xlo=-.2,xhi=.4,ylo=0,yhi=.4
done
1. click on Initcond Range
   Range over: I
   Steps: 20
   Start: -.2
   End: 0.4
   Reset storage:N
2. Redraw
3. Graphics Freeze Freeze

try this for different noise levels (sig=.1,sig=.4)
try it for I&F instead