### AP propagates too slow

Posted:

**Sat Apr 30, 2016 4:23 am**Hi everyone!

I'm doing simulation of AP propagation in pyramidal neuron. However, the propagation speed of AP is very slow, only 0.025 m/s.

In the simulation, I used the classical Hodgkin-Huxley model with classical parameters adapted from paper. (Larkum, Matthew E., et al. "Dendritic properties of turtle pyramidal neurons.")

According to experiment results, the propagation speed of AP in unmyelinated neuron should 0.5-2 m/s. (https://en.wikipedia.org/wiki/Nerve_conduction_velocity)

Also I used the same parameters to run the HH model with a MATLAB code, and I got 1 m/s for speed.

So I'm just wondering what the determinants of propagation speed of AP in the NEURON.

Any suggestions?

I'm doing simulation of AP propagation in pyramidal neuron. However, the propagation speed of AP is very slow, only 0.025 m/s.

In the simulation, I used the classical Hodgkin-Huxley model with classical parameters adapted from paper. (Larkum, Matthew E., et al. "Dendritic properties of turtle pyramidal neurons.")

According to experiment results, the propagation speed of AP in unmyelinated neuron should 0.5-2 m/s. (https://en.wikipedia.org/wiki/Nerve_conduction_velocity)

Also I used the same parameters to run the HH model with a MATLAB code, and I got 1 m/s for speed.

So I'm just wondering what the determinants of propagation speed of AP in the NEURON.

Any suggestions?

Code: Select all

```
cell_parameters = {
'morphology': self.morphology_name,
'v_init': -65,
'rm': 54000,
'passive': False,
'nsegs_method': 'lambda_f',
'lambda_f': 400, # Higher number means higher spatial resolution of the cell
'timeres_NEURON': 2**-3, # Should be a power of 2
'timeres_python': 2**-3,
'tstartms': 0,
'tstopms': 50,
}
cell = LFPy.Cell(**cell_parameters)
for i,sec in enumerate(cell.allseclist):
if i == 0:
sec.Ra = 75 # Ohm cm
sec.cm = 1.5 # uF / cm2
sec.insert('hh')
sec.gnabar_hh = 0.083 # S/cm2
sec.gkbar_hh = 0.03 # S/cm2
sec.gl_hh = 0.0003 # S/cm2
sec.ena = 55 # mV
sec.ek = -72 # mV
sec.el_hh = -49.3 # mV
else:
sec.Ra = 75 # Ohm cm
sec.cm = 3 # uF / cm2
sec.insert('hh')
sec.gnabar_hh = 0.083 # S/cm2
sec.gkbar_hh = 0.03 # S/cm2
sec.gl_hh = 0.0003 # S/cm2
sec.ena = 55 # mV
sec.ek = -72 # mV
sec.el_hh = -49.3 # mV
```