def preliminary():
"""Creates a preliminary template"""
stf.set_peak_start(209900)
stf.set_peak_end(210500)
stf.set_fit_start(209900)
stf.set_fit_end(210400)
stf.set_peak_mean(3)
stf.set_base_start(209600)
stf.set_base_end(209900)
stf.measure()
return stf.leastsq(5)
def batch_cursors():
"""Sets appropriate cursor positions for analysing
the extracted events."""
stf.set_peak_start(100)
stf.set_peak_end(598)
stf.set_fit_start(120)
stf.set_fit_end(598)
stf.set_peak_mean(3)
stf.set_base_start(0)
stf.set_base_end(100)
stf.measure()
def final():
"""Creates a final template"""
stf.set_peak_start(100)
stf.set_peak_end(599)
stf.set_fit_start(100)
stf.set_fit_end(599)
stf.set_peak_mean(3)
stf.set_base_start(0)
stf.set_base_end(100)
stf.measure()
return stf.leastsq(5)
def preliminary():
"""Creates a preliminary template"""
stf.set_peak_start(209900)
stf.set_peak_end(210500)
stf.set_fit_start(209900)
stf.set_fit_end(210400)
stf.set_peak_mean(3)
stf.set_base_start(209600)
stf.set_base_end(209900)
stf.measure()
return stf.leastsq(5)
def batch_cursors():
"""Sets appropriate cursor positions for analysing
the extracted events."""
stf.set_peak_start(100)
stf.set_peak_end(598)
stf.set_fit_start(120)
stf.set_fit_end(598)
stf.set_peak_mean(3)
stf.set_base_start(0)
stf.set_base_end(100)
stf.measure()
def final():
"""Creates a final template"""
stf.set_peak_start(100)
stf.set_peak_end(599)
stf.set_fit_start(100)
stf.set_fit_end(599)
stf.set_peak_mean(3)
stf.set_base_start(0)
stf.set_base_end(100)
stf.measure()
return stf.leastsq(5)
def yvalue(origin, interval):
stf.set_fit_start(origin, True)
stf.set_fit_end(origin + interval, True)
stf.measure()
x = int(stf.get_fit_end(False))
y = []
for i in range(stf.get_size_channel()):
stf.set_trace(i)
y.append(stf.get_trace(i)[x])
return y
def fit_experiment(params, pulse_length, function_to_fit):
num_sweeps = stf.get_size_channel()
stf.set_channel(0)
stf.set_trace(0)
#jjm_analysis.set_params(params);
#stf.measure();
#this is in samples
#peak_index = stf.peak_index();
#stf.set_fit_start(peak_index, is_time=False);
#fit_start_time = peak_index*stf.get_sampling_interval();
#stf.set_fit_end(fit_start_time+pulse_length-(10*stf.get_sampling_interval()), is_time=True);
#fit_func = stf.leastsq(function_to_fit);
#fit_func['Baseline(pA)']=stf.get_base();
#fit_df = pd.DataFrame(fit_func, index=[0]);
fits = []
traces = []
for x in range(0, num_sweeps):
stf.set_trace(x)
jjm_analysis.set_params(params)
stf.measure()
#this is in samples
peak_index = stf.peak_index()
stf.set_fit_start(peak_index, is_time=False)
fit_start_time = peak_index * stf.get_sampling_interval()
stf.set_fit_end(fit_start_time + pulse_length -
(10 * stf.get_sampling_interval()),
is_time=True)
sweep_fit = stf.leastsq(function_to_fit)
sweep_fit['Baseline(pA)'] = stf.get_base()
fits.append(sweep_fit)
traces.append(x)
fit_df = pd.DataFrame(fits)
return (fit_df)
def EPSPtrains(latency=200,
numStim=4,
intvlList=[1, 0.8, 0.6, 0.4, 0.2, 0.1, 0.08, 0.06, 0.04, 0.02]):
# Initialize
numTrains = len(intvlList) # Number of trains
intvlArray = np.array(intvlList) * 1000 # Units in ms
si = stf.get_sampling_interval() # Units in ms
# Background subtraction
traceBaselines = []
subtractedTraces = []
k = 1e-4
x = [i * stf.get_sampling_interval() for i in range(stf.get_size_trace())]
for i in range(numTrains):
stf.set_trace(i)
z = x
y = stf.get_trace()
traceBaselines.append(y)
ridx = []
if intvlArray[i] > 500:
for j in range(numStim):
ridx += range(
int(round(((intvlArray[i] * j) + latency - 1) / si)),
int(round(
((intvlArray[i] * (j + 1)) + latency - 1) / si)) - 1)
else:
ridx += range(
int(round((latency - 1) / si)),
int(
round(((intvlArray[i] *
(numStim - 1)) + latency + 500) / si)) - 1)
ridx += range(int(round(4999 / si)), int(round(5199 / si)))
z = np.delete(z, ridx, 0)
y = np.delete(y, ridx, 0)
yi = np.interp(x, z, y)
yf = signal.symiirorder1(yi, (k**2), 1 - k)
traceBaselines.append(yf)
subtractedTraces.append(stf.get_trace() - yf)
stf.new_window_list(traceBaselines)
stf.new_window_list(subtractedTraces)
# Measure depolarization
# Initialize variables
a = []
b = []
# Set baseline start and end cursors
stf.set_base_start(np.round(
(latency - 50) / si)) # Average during 50 ms period before stimulus
stf.set_base_end(np.round(latency / si))
# Set fit start cursor
stf.set_fit_start(np.round(latency / si))
stf.set_fit_end(
np.round(((intvlArray[1] * (numStim - 1)) + latency + 1000) /
si)) # Include a 1 second window after last stimulus
# Start AUC calculations
for i in range(numTrains):
stf.set_trace(i)
stf.measure()
b.append(stf.get_base())
n = int(stf.get_fit_end() + 1 - stf.get_fit_start())
x = np.array([k * stf.get_sampling_interval() for k in range(n)])
y = stf.get_trace()[int(stf.get_fit_start()):int(stf.get_fit_end() +
1)]
a.append(np.trapz(y - b[i], x)) # Units in V.s
return a
def wcp(V_step=-5, step_start=10, step_duration=20):
"""
Measures whole cell properties. Specifically, this function returns the
voltage clamp step estimates of series resistance, input resistance, cell
membrane resistance, cell membrane capacitance, cell surface area and
specific membrane resistance.
The series (or access) resistance is obtained my dividing the voltage step
by the peak amplitude of the current transient (Ogden, 1994): Rs = V / Ip
The input resistance is obtained by dividing the voltage step by the average
amplitude of the steady-state current (Barbour, 2014): Rin = V / Iss
The cell membrane resistance is calculated by subtracting the series
resistance from the input resistance (Barbour, 1994): Rm = Rin - Rs
The cell membrane capacitance is estimated by dividing the transient charge
by the size of the voltage-clamp step (Taylor et al. 2012): Cm = Q / V
The cell surface area is estimated by dividing the cell capacitance by the
specific cell capacitance, c (1.0 uF/cm^2; Gentet et al. 2000; Niebur, 2008):
Area = Cm / c
The specific membrane resistance is calculated by multiplying the cell
membrane resistance with the cell surface area: rho = Rm * Area
Users should be aware of the approximate nature of determining cell
capacitance and derived parameters from the voltage-clamp step method
(Golowasch, J. et al., 2009)
References:
Barbour, B. (2014) Electronics for electrophysiologists. Microelectrode
Techniques workshop tutorial.
www.biologie.ens.fr/~barbour/electronics_for_electrophysiologists.pdf
Gentet, L.J., Stuart, G.J., and Clements, J.D. (2000) Direct measurement
of specific membrane capacitance in neurons. Biophys J. 79(1):314-320
Golowasch, J. et al. (2009) Membrane Capacitance Measurements Revisited:
Dependence of Capacitance Value on Measurement Method in Nonisopotential
Neurons. J Neurophysiol. 2009 Oct; 102(4): 2161-2175.
Niebur, E. (2008), Scholarpedia, 3(6):7166. doi:10.4249/scholarpedia.7166
www.scholarpedia.org/article/Electrical_properties_of_cell_membranes
(revision #13938, last accessed 30 April 2018)
Ogden, D. Chapter 16: Microelectrode electronics, in Ogden, D. (ed.)
Microelectrode Techniques. 1994. 2nd Edition. Cambridge: The Company
of Biologists Limited.
Taylor, A.L. (2012) What we talk about when we talk about capacitance
measured with the voltage-clamp step method J Comput Neurosci.
32(1):167-175
"""
# Error checking
if stf.get_yunits() != "pA":
raise ValueError('The recording is not voltage clamp')
# Prepare variables from input arguments
si = stf.get_sampling_interval()
t0 = step_start / si
l = step_duration / si
# Set cursors and update measurements
stf.set_base_start((step_start - 1) / si)
stf.set_base_end(t0 - 1)
stf.set_peak_start(t0)
stf.set_peak_end((step_start + 1) / si)
stf.set_fit_start(t0)
stf.set_fit_end(t0 + l - 1)
stf.set_peak_direction("both")
stf.measure()
# Calculate series resistance (Rs) from initial transient
b = stf.get_base()
Rs = 1000 * V_step / (stf.get_peak() - b) # in Mohm
# Calculate charge delivered during the voltage clamp step
n = int(stf.get_fit_end() + 1 - stf.get_fit_start())
x = [i * stf.get_sampling_interval() for i in range(n)]
y = stf.get_trace()[int(stf.get_fit_start()):int(stf.get_fit_end() + 1)]
Q = np.trapz(y - b, x)
# Set cursors and update measurements
stf.set_base_start(t0 + l - 1 - (step_duration / 4) / si)
stf.set_base_end(t0 + l - 1)
stf.measure()
# Measure steady state current and calculate input resistance
I = stf.get_base() - b
Rin = 1000 * V_step / I # in Mohm
# Calculate cell membrane resistance
Rm = Rin - Rs # in Mohm
# Calculate voltage-clamp step estimate of the cell capacitance
t = x[-1] - x[0]
Cm = (Q - I * t) / V_step # in pF
# Estimate membrane surface area, where the capacitance per unit area is 1.0 uF/cm^2
A = Cm * 1e-06 / 1.0 # in cm^2
# Calculate specific membrane resistance
rho = 1e+03 * Rm * A # in kohm.cm^2; usually 10 at rest
# Create table of results
retval = []
retval += [("Holding current (pA)", b)]
retval += [("Series resistance (Mohm)", Rs)]
retval += [("Input resistance (Mohm)", Rin)]
retval += [("Cell resistance (Mohm)", Rm)]
retval += [("Cell capacitance (pF)", Cm)]
retval += [("Surface area (um^2)", A * 1e+04**2)]
retval += [("Membrane resistivity (kohm.cm^2)", rho)]
retval = dict(retval)
stf.show_table(retval, "Whole-cell properties")
return retval
def glu_iv(pulses=13, subtract_base=True):
"""Calculates an iv from a repeated series of fast application and
voltage pulses.
Keyword arguments:
pulses -- Number of pulses for the iv.
subtract_base -- If True (default), baseline will be subtracted.
Returns:
True if successful.
"""
# Some ugly definitions for the time being
# Cursors are in ms here.
gFitEnd = 330.6 # fit end cursor is variable
gFSelect = 0 # Monoexp
gDictSize = stf.leastsq_param_size(
gFSelect) + 2 # Parameters, chisqr, peak value
gBaseStart = 220.5 # Start and end of the baseline before the control pulse, in ms
gBaseEnd = 223.55
gPeakStart = 223.55 # Start and end of the peak cursors for the control pulse, in ms
gPeakEnd = 253.55
if (gDictSize < 0):
print('Couldn\'t retrieve function id=%d, aborting now.' % gFSelect)
return False
if (not (stf.check_doc())):
print('Couldn\'t find an open file; aborting now.')
return False
# analyse iv, subtract baseline if requested:
ivtools.analyze_iv(pulses)
if (subtract_base == True):
if (not (stf.set_base_start(gBaseStart, True))): return False
if (not (stf.set_base_end(gBaseEnd, True))): return False
stf.measure()
stf.select_all()
stf.subtract_base()
# set cursors:
if (not (stf.set_peak_start(gPeakStart, True))): return False
if (not (stf.set_peak_end(gPeakEnd, True))): return False
if (not (stf.set_base_start(gBaseStart, True))): return False
if (not (stf.set_base_end(gBaseEnd, True))): return False
if (not (stf.set_fit_end(gFitEnd, True))): return False
if (not (stf.set_peak_mean(3))): return False
if (not (stf.set_peak_direction("both"))): return False
# A list for dictionary keys and values:
dict_keys = []
dict_values = np.empty((gDictSize, stf.get_size_channel()))
firstpass = True
for n in range(0, stf.get_size_channel()):
if (stf.set_trace(n) == False):
print('Couldn\'t set a new trace; aborting now.')
return False
print('Analyzing trace %d of %d' % (n + 1, stf.get_size_channel()))
# set the fit window cursors:
if (not (stf.set_fit_start(stf.peak_index()))): return False
# Least-squares fitting:
p_dict = stf.leastsq(gFSelect)
if (p_dict == 0):
print('Couldn\'t perform a fit; aborting now.')
return False
# Create an empty list:
tempdict_entry = []
row = 0
for k, v in p_dict.iteritems():
if (firstpass == True):
dict_keys.append(k)
dict_values[row][n] = v
row = row + 1
if (firstpass):
dict_keys.append("Peak amplitude")
dict_values[row][n] = stf.get_peak() - stf.get_base()
firstpass = False
retDict = dict()
# Create the dictionary for the table:
entry = 0
for elem in dict_keys:
retDict[elem] = dict_values[entry].tolist()
entry = entry + 1
return stf.show_table_dictlist(retDict)
def glu_iv( pulses = 13, subtract_base=True ):
"""Calculates an iv from a repeated series of fast application and
voltage pulses.
Keyword arguments:
pulses -- Number of pulses for the iv.
subtract_base -- If True (default), baseline will be subtracted.
Returns:
True if successful.
"""
# Some ugly definitions for the time being
# Cursors are in ms here.
gFitEnd = 330.6 # fit end cursor is variable
gFSelect = 0 # Monoexp
gDictSize = stf.leastsq_param_size( gFSelect ) + 2 # Parameters, chisqr, peak value
gBaseStart = 220.5 # Start and end of the baseline before the control pulse, in ms
gBaseEnd = 223.55
gPeakStart = 223.55 # Start and end of the peak cursors for the control pulse, in ms
gPeakEnd = 253.55
if ( gDictSize < 0 ):
print('Couldn\'t retrieve function id=%d, aborting now.'%gFSelect)
return False
if ( not(stf.check_doc()) ):
print('Couldn\'t find an open file; aborting now.')
return False
# analyse iv, subtract baseline if requested:
ivtools.analyze_iv( pulses )
if ( subtract_base == True ):
if ( not(stf.set_base_start( gBaseStart, True )) ): return False
if ( not(stf.set_base_end( gBaseEnd, True )) ): return False
stf.measure()
stf.select_all()
stf.subtract_base()
# set cursors:
if ( not(stf.set_peak_start( gPeakStart, True )) ): return False
if ( not(stf.set_peak_end( gPeakEnd, True )) ): return False
if ( not(stf.set_base_start( gBaseStart, True )) ): return False
if ( not(stf.set_base_end( gBaseEnd, True )) ): return False
if ( not(stf.set_fit_end( gFitEnd, True )) ): return False
if ( not(stf.set_peak_mean( 3 )) ): return False
if ( not(stf.set_peak_direction( "both" )) ): return False
# A list for dictionary keys and values:
dict_keys = []
dict_values = np.empty( (gDictSize, stf.get_size_channel()) )
firstpass = True
for n in range( 0, stf.get_size_channel() ):
if ( stf.set_trace( n ) == False ):
print('Couldn\'t set a new trace; aborting now.')
return False
print('Analyzing trace %d of %d'%( n+1, stf.get_size_channel() ) )
# set the fit window cursors:
if ( not(stf.set_fit_start( stf.peak_index() )) ): return False
# Least-squares fitting:
p_dict = stf.leastsq( gFSelect )
if ( p_dict == 0 ):
print('Couldn\'t perform a fit; aborting now.')
return False
# Create an empty list:
tempdict_entry = []
row = 0
for k, v in p_dict.iteritems():
if ( firstpass == True ):
dict_keys.append( k )
dict_values[row][n] = v
row = row+1
if ( firstpass ):
dict_keys.append( "Peak amplitude" )
dict_values[row][n] = stf.get_peak()-stf.get_base()
firstpass = False
retDict = dict()
# Create the dictionary for the table:
entry = 0
for elem in dict_keys:
retDict[ elem ] = dict_values[entry].tolist()
entry = entry+1
return stf.show_table_dictlist( retDict )