from neuron import h, gui
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.colors as colors
import matplotlib.cm as cmx
dtype = np.float64
# one-compartment cell (soma)
soma = h.Section(name='soma')
soma.diam = 50 # micron
soma.L = 63.66198 # micron, so that area = 10000 micron2
soma.nseg = 1 # adimensional
soma.cm = 1 # uF/cm2
soma.Ra = 70 # ohm-cm
soma.nseg = 1
soma.insert('na15') # insert mechanism
soma.ena = 65
h.celsius = 24 # temperature in celsius
v_init = -120 # holding potential
h.dt = 0.05 # ms - value of the fundamental integration time step, dt, used by fadvance().
# clamping parameters
st_dur = 10 # conditioning stimulus initial duration (ms)
end_dur = 10000 # conditioning stimulus final duration (ms)
dens = 0
dur = 10
num_pts = 30 # number of points in logaritmic scale
# vector containing 'num_pts' values equispaced between log10(st_dur) and log10(end_dur)
vec_pts = np.logspace(np.log10(st_dur), np.log10(end_dur), num=num_pts)
L = len(vec_pts)
# vectors for data handling
rec_vec = h.Vector()
time_vec = h.Vector()
log_time_vec = h.Vector()
t_vec = h.Vector()
v_vec_t = h.Vector()
i_vec_t = h.Vector()
# saving data (comment the following 4 lines if you don't want to save the data)
f1 = open('4_on_s_inact_time_vec.dat', 'w')
f2 = open('4_on_s_inact_rec_vec.dat', 'w')
f1.write("time=[\n")
f2.write("fractional_recovery=[\n")
# voltage clamp with "five" levels
f3cl = h.VClamp_plus(soma(0.5))
f3cl.dur[0] = 5 # ms
f3cl.amp[0] = -120 # mV
f3cl.dur[1] = dur # ms
f3cl.amp[1] = -20 # mV
f3cl.dur[2] = 30 # ms
f3cl.amp[2] = -120 # mV
f3cl.dur[3] = 20 # ms
f3cl.amp[3] = -20 # mV
f3cl.dur[4] = 5 # ms
f3cl.amp[4] = -120 # mV
# finding the "initial state variables values"
from state_variables import finding_state_variables
initial_values = [x for x in finding_state_variables(v_init,h.celsius)]
print('Initial values [C1, C2, O1, I1, I2]= ', initial_values)
for seg in soma:
seg.na15.iC1=initial_values[0]
seg.na15.iC2=initial_values[1]
seg.na15.iO1=initial_values[2]
seg.na15.iI1=initial_values[3]
seg.na15.iI2=initial_values[4]
# figure definition
fig, ax = plt.subplots(2, 2,figsize=(18,6))
ln0, = ax[0,0].plot([], [], '*')
ln1, = ax[0,1].plot([], [], '-')
ln2, = ax[1,0].plot([], [], '-')
ln3, = ax[1,1].plot([], [], '-')
fig.suptitle('4. Development of slow inactivation', fontsize=15, fontweight='bold')
fig.subplots_adjust(wspace=0.5)
fig.subplots_adjust(hspace=0.5)
ax[0,0].set_xlim(-200, 5 + end_dur +30 + 20 + 5 + 100)
ax[0,0].set_ylim(-121,0)
ax[0,0].set_xlabel('Time $(ms)$')
ax[0,0].set_ylabel('Voltage $(mV)$')
ax[0,0].set_title('Time/Voltage relation')
ax[0,1].set_xlim(-200, 5 + end_dur +30 + 20 + 5 + 100)
ax[0,1].set_ylim(-1.75,0.2)
ax[0,1].set_xlabel('Time $(ms)$')
ax[0,1].set_ylabel('Current density $(mA/cm^2)$')
ax[0,1].set_title('Time/Current density relation')
ax[1,0].set_xlim(-200, 5 + end_dur +30 + 20 + 5 + 100)
ax[1,0].set_ylim(-0.1, 1.1)
ax[1,0].set_xlabel('Time $(ms)$')
ax[1,0].set_ylabel('Fractional recovery (P2/P1)')
ax[1,0].set_title('Time/Fractional recovery (P2/P1)')
ax[1,1].set_xlim(0.7,4.1)
ax[1,1].set_ylim(-0.1, 1.1)
ax[1,1].set_xlabel('Log(Time)')
ax[1,1].set_ylabel('Fractional recovery (P2/P1)')
ax[1,1].set_title('Log(Time)/Fractional recovery (P2/P1)')
# to plot in rainbow colors
values=range(L)
rbw = cm = plt.get_cmap('rainbow')
cNorm = colors.Normalize(vmin=0, vmax=values[-1])
scalarMap = cmx.ScalarMappable(norm=cNorm, cmap=rbw)
# clamping definition
def Clamp(dur):
f3cl.dur[1] = dur
h.tstop = 5 + dur +30 + 20 + 5
h.finitialize(v_init)
#variables initialization
dens = 0
peak_curr1 = 0
peak_curr2 = 0
while (h.t<h.tstop): # runs a single trace, calculates peak current
dens = f3cl.i/soma(0.5).area()*100.0-soma(0.5).i_cap # clamping current in mA/cm2, for each dt
t_vec.append(h.t)
v_vec_t.append(soma.v)
i_vec_t.append(dens)
if ((h.t>5)and(h.t<15)): # evaluate the first peak
if(abs(dens)>peak_curr1):
peak_curr1=abs(dens)
if ((h.t>(35.03+dur))and(h.t<(45+dur))): # evaluate the second peak
if(abs(dens)>peak_curr2):
peak_curr2=abs(dens)
h.fadvance()
# updates the vectors at the end of the run
time_vec.append(dur)
log_time_vec.append(np.log10(dur))
rec_vec.append(peak_curr2/peak_curr1)
### start program
def start():
k=0 #counter
for dur in vec_pts:
# resizing the vectors
t_vec.resize(0)
i_vec_t.resize(0)
v_vec_t.resize(0)
rec_vec.resize(0)
time_vec.resize(0)
log_time_vec.resize(0)
Clamp(dur)
colorVal1 = scalarMap.to_rgba(k)
k+=1
ln0,=ax[0,0].plot(t_vec, v_vec_t, color=colorVal1)
ln1,=ax[0,1].plot(t_vec, i_vec_t, color=colorVal1)
ln2=ax[1,0].scatter(time_vec, rec_vec, c=colorVal1)
ln3=ax[1,1].scatter(log_time_vec, rec_vec, c=colorVal1)
# printing and saving data (comment the following 6 lines if you don't want to print and save the data)
for i in time_vec:
print ('time: ', i,'ms')
f1.write("%s ,\n" % i)
for i in rec_vec:
print('fractional recovery (P2/P1): ',i)
f2.write("%s ,\n" % i)
#to save the figure (comment the following line if you don't want to save the figure)
plt.savefig('4. Development of slow inactivation', format='pdf', dpi=300, orientation='portrait')
# comment the following 4 lines if you don't want to save the data
f1.write("];")
f2.write("];")
f1.close()
f2.close()
plt.show()
start()