Change bulk resistivity default.

* Align defaults with values used in most of the NEURON
  validation scripts.
* Use consistent 100 Ω·m bulk resistivity across both
  NEURON test models and basic validation cells.

nrn/soma.py

@@ -10,7 +10,8 @@ V.override_defaults_from_args()
 geom = [(0,1), (100, 1)]
 
 model = V.VModel()
-model.add_soma(18.8, Ra=123)
+
+model.add_soma(18.8, Ra=100)
 model.add_iclamp(10, 100, 0.1)
 
 # NB: this doesn't seem to have converged with

src/parameter_list.hpp

@@ -155,7 +155,7 @@ namespace mc {
             // r_L is called Ra in Neuron
             //base::add_parameter({"c_m",  10e-6, {0., 1e9}}); // typically 10 nF/mm^2 == 0.01 F/m^2 == 10^-6 F/cm^2
             base::add_parameter({"c_m",   0.01, {0., 1e9}}); // typically 10 nF/mm^2 == 0.01 F/m^2 == 10^-6 F/cm^2
-            base::add_parameter({"r_L", 180.00, {0., 1e9}}); // equivalent to Ra in Neuron : Ohm.cm
+            base::add_parameter({"r_L", 100.00, {0., 1e9}}); // equivalent to Ra in Neuron : Ohm.cm
         }
     };
 

tests/test_common_cells.hpp

@@ -12,7 +12,7 @@ namespace mc {
  * Soma:
  *    diameter: 18.8 µm
  *    mechanisms: HH (default params)
- *    bulk resistivitiy: 123 Ω·cm
+ *    bulk resistivitiy: 100 Ω·cm
  *
  * Stimuli:
  *    soma centre, t=[10 ms, 110 ms), 0.1 nA
@@ -22,7 +22,7 @@ inline cell make_cell_soma_only(bool with_stim = true) {
     cell c;
 
     auto soma = c.add_soma(18.8/2.0);
-    soma->mechanism("membrane").set("r_L", 123);
+    soma->mechanism("membrane").set("r_L", 100);
     soma->add_mechanism(hh_parameters());
 
     if (with_stim) {