Clarify that spike detector can serve as endpoint in connection. (#1339)

doc/python/interconnectivity.rst

@@ -14,11 +14,11 @@ Interconnectivity
 
     .. attribute:: source
 
-        The source end point of the connection (type: :class:`arbor.cell_member`).
+        The source end point of the connection (type: :class:`arbor.cell_member`, which can be initialized with a (gid, index) tuple).
 
     .. attribute:: dest
 
-        The destination end point of the connection (type: :class:`arbor.cell_member`).
+        The destination end point of the connection (type: :class:`arbor.cell_member`, which can be initialized with a (gid, index) tuple).
 
     .. attribute:: weight
 
@@ -65,3 +65,12 @@ Interconnectivity
     .. attribute:: ggap
 
         The gap junction conductance [μS].
+
+.. class:: spike_detector
+
+    A spike detector, generates a spike when voltage crosses a threshold. Can be used as source endpoint for an :ref:`arbor.connection`.
+
+    .. attribute:: threshold
+
+        Voltage threshold of spike detector [mV]
+

python/cells.cpp

@@ -297,13 +297,13 @@ void register_cells(pybind11::module& m) {
     // arb::threshold_detector
 
     pybind11::class_<arb::threshold_detector> detector(m, "spike_detector",
-            "A spike detector, generates a spike when voltage crosses a threshold.");
+            "A spike detector, generates a spike when voltage crosses a threshold. Can be used as source endpoint for an arbor.connection.");
     detector
         .def(pybind11::init(
             [](double thresh) {
                 return arb::threshold_detector{thresh};
             }), "threshold"_a)
-        .def_readonly("threshold", &arb::threshold_detector::threshold, "Voltage threshold of spike detector [ms]")
+        .def_readonly("threshold", &arb::threshold_detector::threshold, "Voltage threshold of spike detector [mV]")
         .def("__repr__", [](const arb::threshold_detector& d){
             return util::pprintf("<arbor.threshold_detector: threshold {} mV>", d.threshold);})
         .def("__str__", [](const arb::threshold_detector& d){