"""
Wrapper classes to make working with NEURON easier.
Author: Andrew P. Davison, UNIC, CNRS
"""
__version__ = "0.3.0"
from neuron import nrn, h, hclass
import h5py as h5
import numpy as np
from functools import reduce
h.load_file('stdrun.hoc')
PROXIMAL = 0
DISTAL = 1
class Mechanism(object):
"""
Examples:
>>> leak = Mechanism('pas', {'e': -65, 'g': 0.0002})
>>> hh = Mechanism('hh')
"""
def __init__(self, name, **parameters):
self.name = name
self.parameters = parameters
def insert_into(self, section):
section.insert(self.name)
for name, value in list(self.parameters.items()):
for segment in section:
mech = getattr(segment, self.name)
setattr(mech, name, value)
class Section(nrn.Section):
"""
Examples:
>>> soma = Section(L=30, diam=30, mechanisms=[hh, leak])
>>> apical = Section(L=600, diam=2, nseg=5, mechanisms=[leak],
... parent=soma, connection_point=DISTAL)
"""
def __init__(self, name, L, diam, nseg=1, Ra=100, cm=1,
mechanisms=[], parent=None,
connection_point=DISTAL,
point_processes = [],
records=[]):
nrn.Section.__init__(self)
# Set human readable name
self.Name = name
# set geometry
self.L = L
self.diam = diam
self.nseg = nseg
# set cable properties
self.Ra = Ra
self.cm = cm
# connect to parent section
if parent:
self.connect(parent, connection_point, PROXIMAL)
# add ion channels
for mechanism in mechanisms:
mechanism.insert_into(self)
# add point processes
for pp in point_processes:
self.add_pointprocesses(pp['label'], pp['type'], locations=pp['locations'], parameters=pp['parameters'])
# record variables
self.records = {}
self.records['time'] = {'val':h.Vector(),'unit':'ms'}
self.records['time']['val'].record(h._ref_t, sec = self)
for r in records:
self.records['%s_%g'%(r['variable'],r['location'])] = {
'unit':r['unit']}
local_rec = self.records['%s_%g'%(r['variable'],r['location'])]
if 'point_process' in list(r.keys()):
local_rec['val'] = self.record_variable(r['variable'],
location=r['location'],
point_process = r['point_process'])
else:
local_rec['val'] = self.record_variable(r['variable'],
location=r['location'])
def add_pointprocesses(self, label, type, locations=[0.5], parameters={}):
if hasattr(self, label):
raise Exception("Can't overwrite synapse labels (to keep things simple)")
synapse_group = []
for location in locations:
synapse = getattr(h, type)(location, sec=self)
for name, value in list(parameters.items()):
setattr(synapse, name, value)
synapse_group.append(synapse)
if len(synapse_group) == 1:
synapse_group = synapse_group[0]
setattr(self, label, synapse_group)
def add_synapses(self, label, type, locations=[0.5], **parameters):
if hasattr(self, label):
raise Exception("Can't overwrite synapse labels (to keep things simple)")
synapse_group = []
for location in locations:
synapse = getattr(h, type)(location, sec=self)
for name, value in list(parameters.items()):
setattr(synapse, name, value)
synapse_group.append(synapse)
if len(synapse_group) == 1:
synapse_group = synapse_group[0]
setattr(self, label, synapse_group)
add_synapse = add_synapses # for backwards compatibility
def plot(self,
variable,
type_mec='mech',
label='',
location=0.5,
tmin=0,
tmax=5,
xmin=-80,
xmax=40,
view=None,
show=1,
color='k',
line=1,
graph=None):
# Convert color to number
colors = {'r':2,'k':1,'g':4,'b':3,'o':5,'mr':7,'m':9,'y':8,
'1':1,'2':2,'3':3,'4':4,'5':5,'6':6,'7':7,'8':8,'9':9}
color = colors[str(color)]
import neuron.gui
if graph is None:
self.graph = h.Graph(show)
graph = self.graph
h.graphList[0].append(graph)
graph.size(tmin, tmax, xmin, xmax)
if view is not None:
graph.view(view[0],view[1],view[2],
view[3],view[4],view[5],view[6],view[7])
if not label:
label = variable
if 'mech' in type_mec:
if type(variable) == type([]):
for var in variable:
print((self.name(), '%s(%g)' % (var, location)))
self.push()
if h.ismembrane(var):
spine_area = h.area(0.5)
graph.addvar(var,
'ica_%s(%g)' % (var,
location),
color, line, sec=self)
color += 1
h.pop_section()
else:
graph.addvar(variable, '%s(%g)' % (variable, location),
color, line, sec=self)
if 'pp' in type_mec:
graph.addvar(label,
getattr(getattr(self,variable[0]),
'_ref_'+variable[1]),
color, line, sec=self)
graph.flush()
return graph
def record_spikes(self, threshold=-30):
self.spiketimes = h.Vector()
self.spikecount = h.APCount(0.5, sec=self)
self.spikecount.thresh = threshold
self.spikecount.record(self.spiketimes)
def record_variable(self, variable, location=0.5, point_process=None):
v = h.Vector()
if point_process is not None:
eval('v.record(getattr(self,"%s")._ref_%s, sec = self)'%(point_process,variable))
else:
eval('v.record(self(%g)._ref_%s, sec = self)'%(location,variable))
return v
def save_records(self, store, index = None, write_datasets = True):
if index is not None:
g = store.create_group('%s_%g'%(self.Name, index))
else:
g = store.create_group(self.Name)
for r_n,r in list(self.records.items()):
r_g = g.create_group(r_n)
r_u = r_g.create_dataset('Unit', data = np.string_(r['unit']))
if write_datasets:
data = np.array(r['val'])
data_length = data.shape[0]
r_v = r_g.create_dataset('Data',
data = data,
compression="gzip",
compression_opts=9,
chunks=(min(100,data_length),)
)
else:
r_v = r_g.create_dataset('Data',
(1e5,),
dtype = 'float',
compression="gzip")#,
#compression_opts=9)
#chunks=(100,))
def store_records(self, section_group, index = None):
# dset = section_group['%s_%g'%(self.Name, index)]['Data']
if index is not None:
dgroup = section_group['%s_%g'%(self.Name, index)]
else:
dgroup = section_group[self.Name]
print((list(dgroup.keys())))
for r_n,r in list(self.records.items()):
print((dgroup[r_n]['Data']))
data = np.array(r['val'])
print((data.shape))
# dgroup[r_n]['Data'][:] =
# dgroup[r_n]['Data'].resize((500,))
# print dgroup[r_n]['Data']
def balance_currents(self,Vrest):
h.v_init = Vrest
h.init()
# Balance ion currents with leak at Vrest by changing leak Erev
for seg in self:
current = 0
if hasattr(seg,'ica'):
current += seg.ica
if hasattr(seg,'ina'):
current += seg.ina
if hasattr(seg,'ik'):
current += seg.ik
seg.e_pas = seg.v + current / seg.g_pas
def alias(attribute_path):
"""
Returns a new property, mapping an attribute nested in an object hierarchy
to a simpler name
For example, suppose that an object of class A has an attribute b which
itself has an attribute c which itself has an attribute d. Then placing
e = alias('b.c.d')
in the class definition of A makes A.e an alias for A.b.c.d
"""
parts = attribute_path.split('.')
attr_name = parts[-1]
attr_path = parts[:-1]
def set(self, value):
obj = reduce(getattr, [self] + attr_path)
setattr(obj, attr_name, value)
def get(self):
obj = reduce(getattr, [self] + attr_path)
return getattr(obj, attr_name)
return property(fset=set, fget=get)
def uniform_property(section_list, attribute_path):
"""
Define a property that will have a uniform value across a list of sections.
For example, suppose we define a neuron model as a class A, which contains
three compartments: soma, dendrite and axon. Then placing
gnabar = uniform_property(["soma", "axon"], "hh.gnabar")
in the class definition of A means that setting a.gnabar (where a is an
instance of A) will set the value of hh.gnabar in both the soma and axon, i.e.
a.gnabar = 0.01
is equivalent to:
for sec in [a.soma, a.axon]:
for seg in sec:
seg.hh.gnabar = 0.01
"""
parts = attribute_path.split('.')
attr_name = parts[-1]
attr_path = parts[:-1]
def set(self, value):
for sec_name in section_list:
sec = getattr(self, sec_name)
for seg in sec:
obj = reduce(getattr, [seg] + attr_path)
setattr(obj, attr_name, value)
def get(self):
sec = getattr(self, section_list[0])
obj = reduce(getattr, [sec(0.5)] + attr_path)
return getattr(obj, attr_name)
return property(fset=set, fget=get)
if __name__ == "__main__":
class SimpleNeuron(object):
def __init__(self):
# define ion channel parameters
leak = Mechanism('pas', e=-65, g=0.0002)
hh = Mechanism('hh')
# create cable sections
self.soma = Section(L=30, diam=30, mechanisms=[hh])
self.apical = Section(L=600, diam=2, nseg=5, mechanisms=[leak], parent=self.soma,
connection_point=DISTAL)
self.basilar = Section(L=600, diam=2, nseg=5, mechanisms=[leak], parent=self.soma,
connection_point=0.5)
self.axon = Section(L=1000, diam=1, nseg=37, mechanisms=[hh],
connection_point=0)
# synaptic input
self.soma.add_synapses('syn', 'AlphaSynapse', onset=0.5, gmax=0.05, e=0)
gnabar = uniform_property(["soma", "axon"], "hh.gnabar")
gkbar = uniform_property(["soma", "axon"], "hh.gkbar")
neuron = SimpleNeuron()
neuron.soma.plot('v')
neuron.apical.plot('v')
neuron.gnabar = 0.15
assert neuron.soma(0.5).hh.gnabar == 0.15
h.dt = 0.025
v_init = -65
tstop = 5
h.finitialize(v_init)
h.run()
