**Name:**

aeif_cond_alpha_multisynapse - Conductance based adaptive exponential

integrate-and-fire neuron model according

to Brette and Gerstner (2005) with

multiple synaptic rise time and decay

time constants, and synaptic conductance

modeled by an alpha function.

**Examples:**

import nest

import numpy as np

neuron = nest.Create('aeif_cond_alpha_multisynapse')

nest.SetStatus(neuron, {"V_peak": 0.0, "a": 4.0, "b":80.5})

nest.SetStatus(neuron, {'E_rev':[0.0, 0.0, 0.0, -85.0],

'tau_syn':[1.0, 5.0, 10.0, 8.0]})

spike = nest.Create('spike_generator', params = {'spike_times':

np.array([10.0])})

voltmeter = nest.Create('voltmeter', 1, {'withgid': True})

delays=[1.0, 300.0, 500.0, 700.0]

w=[1.0, 1.0, 1.0, 1.0]

for syn in range(4):

nest.Connect(spike, neuron, syn_spec={'model': 'static_synapse',

'receptor_type': 1 + syn,

'weight': w[syn],

'delay': delays[syn]})

nest.Connect(voltmeter, neuron)

nest.Simulate(1000.0)

dmm = nest.GetStatus(voltmeter)[0]

Vms = dmm["events"]["V_m"]

ts = dmm["events"]["times"]

import pylab

pylab.figure(2)

pylab.plot(ts, Vms)

pylab.show()

**Description:**

aeif_cond_alpha_multisynapse is a conductance-based adaptive exponential

integrate-and-fire neuron model. It allows an arbitrary number of synaptic

time constants. Synaptic conductance is modeled by an alpha function, as

described by A. Roth and M.C.W. van Rossum in Computational Modeling Methods

for Neuroscientists, MIT Press 2013, Chapter 6.

The time constants are supplied by an array, "tau_syn", and the pertaining

synaptic reversal potentials are supplied by the array "E_rev". Port numbers

are automatically assigned in the range from 1 to n_receptors.

During connection, the ports are selected with the property "receptor_type".

The membrane potential is given by the following differential equation:

C dV/dt = -g_L(V-E_L) + g_L*Delta_T*exp((V-V_T)/Delta_T) + I_syn_tot(V, t)

- w + I_e

where

I_syn_tot(V,t) = \sum_i g_i(t) (V - E_{rev,i}) ,

the synapse i is excitatory or inhibitory depending on the value of E_{rev,i}

and the differential equation for the spike-adaptation current w is:

tau_w * dw/dt = a(V - E_L) - w

When the neuron fires a spike, the adaptation current w <- w + b.

**Parameters:**

C_m double - Capacity of the membrane in pF

t_ref double - Duration of refractory period in ms.

V_reset double - Reset value for V_m after a spike. In mV.

E_L double - Leak reversal potential in mV.

g_L double - Leak conductance in nS.

I_e double - Constant external input current in pA.

Delta_T double - Slope factor in mV

V_th double - Spike initiation threshold in mV

V_peak double - Spike detection threshold in mV.

Adaptation parameters:

a double - Subthreshold adaptation in nS.

b double - Spike-triggered adaptation in pA.

tau_w double - Adaptation time constant in ms

Synaptic parameters

E_rev double vector - Reversal potential in mV.

tau_syn double vector - Time constant of synaptic conductance in ms

Integration parameters

gsl_error_tol double - This parameter controls the admissible error of the

GSL integrator. Reduce it if NEST complains about

numerical instabilities.

**Require:**

HAVE_GSL

**Receives:**

SpikeEvent, CurrentEvent, DataLoggingRequest

author: Hans Ekkehard Plesser, based on aeif_cond_beta_multisynapse

**Sends:**

SpikeEvent

**SeeAlso:**

**Source:**

/home/graber/work-nest/nest-git/nest-simulator/models/aeif_cond_alpha_multisynapse.h