Dear Thierry,

I assume you are using NEST 2.20, not 2.2?

Noisy spike generators usually send individual realisations of random spike trains to each target. Therefore, the only way to record the same spike trains that actually enter the neurons is to put parrot_neurons between the generator and the actual target and then connect the parrot to the target. A setup for multiple neurons would be like below. We need one parrot per actual neuron to get the individual spike trains.

N = 20

gen = nest.Create('sinusoidal_poisson_generator', params={'amplitude':50.,'rate':15.0 })

parrots = nest.Create('parrot_neuron', N)

neurons = nest.Create('ht_neuron', N)

rec = nest.Create('spike_detector')

receptors=nest.GetDefaults('ht_neuron')['receptor_types']

nest.Connect(gen, parrots)

nest.Connect(parrots, neurons, 'one_to_one', {'model': 'static_synapse', 'receptor_type': receptors['AMPA'], 'weight':10.})

nest.Connect(parrots, rec)

Best,

Hans Ekkehard

--

Prof. Dr. Hans Ekkehard Plesser

Head, Department of Data Science

Faculty of Science and Technology

Norwegian University of Life Sciences

PO Box 5003, 1432 Aas, Norway

Phone +47 6723 1560

Email hans.ekkehard.plesser@nmbu.no

Home http://arken.nmbu.no/~plesser

On 03/01/2022, 11:09, "thierry nieus" <thierry.ralph.nieus@gmail.com> wrote:

Dear all, 

first of all, happy new year!

I am using nest 2.2 (installed by conda) and I have set up a simple network of 20-100 neurons based on the ht_neuron model.  I am delivering some noise to all neurons with the sinusoidal_poisson_generator (I can switch to another) and the simulation produces the results I am looking for. 

However I would like now to have a look at the spikes entering the network and therefore I need to access all events generated by the random generator.

A sample of my code is: 

import nest 

receptors=nest.GetDefaults('ht_neuron')['receptor_types']

nest.CopyModel("sinusoidal_poisson_generator",'sin_pois',{'amplitude':50.,'rate':15.0 })

nest.CopyModel("static_synapse","AMPAnoise",{"receptor_type":receptors["AMPA"],"weight":10. })

neurons=nest.Create("ht_neuron",1)

noise=nest.Create('sin_pois',1)

g = nest.Create('sin_pois', 1)

# current pulse

dc_gen = nest.Create("dc_generator")

nest.SetStatus(dc_gen, {"amplitude": 20., "start": 400, "stop": 1050})

nest.Connect(dc_gen, neurons, 'one_to_one')

# recorders

detect_noise = nest.Create('spike_detector', 1)

nest.Connect(noise, neurons, 'one_to_one', syn_spec="AMPAnoise")

nest.Connect(noise, detect_noise, 'one_to_one')

''' the latest does not work

    Creation of connection is not possible because:

    All outgoing connections from a device must use the same synapse type.

'''

Is there a way to record those spikes ? 

Thanks in advance for any help

Best