State and fix unit of conductance in point process NMODL (#1497)

mechanisms/default/expsyn.mod

@@ -6,6 +6,7 @@ NEURON {
 
 UNITS {
     (mV) = (millivolt)
+    (uS) = (microsiemens)
 }
 
 PARAMETER {
@@ -16,7 +17,7 @@ PARAMETER {
 ASSIGNED {}
 
 STATE {
-    g
+    g (uS)
 }
 
 INITIAL {

mechanisms/default/expsyn_stdp.mod

@@ -18,7 +18,7 @@ PARAMETER {
     Apre = 0.01 : pre-synaptic contribution
     Apost = -0.01  : post-synaptic contribution
     e = 0   (mV) : reversal potential
-    max_weight = 10 (nS) : maximum synaptic conductance
+    max_weight = 10 (uS) : maximum synaptic conductance
 }
 
 STATE {