g[0].addexpr("v(.5)", 2, 0)
g[0].size(0,20,-100,50)

v_init = -65
tstop = 20

soma.pna_leak = 2.07e-07
soma.pk_leak = 3.45e-06
soma.nai = 31
soma.nao = 145
soma.ki = 135
soma.ko = 3.1
cai0_ca_ion= 5e-05
cao0_ca_ion= 2
soma.cli = 7
soma.clo = 120
soma.mgo = 1