diff --git a/.gitignore b/.gitignore
index 5b2a2e58a..9d0e23327 100644
--- a/.gitignore
+++ b/.gitignore
@@ -89,6 +89,7 @@ lib/
 
 # log4cplus logging files
 build/Output/Debug/*.txt
+build/Output/Debug/*.txt*
 
 # Result files
 build/Output/*.xml
diff --git a/Simulator/Connections/NG911/Connections911.cpp b/Simulator/Connections/NG911/Connections911.cpp
index a32162969..e30d3f466 100644
--- a/Simulator/Connections/NG911/Connections911.cpp
+++ b/Simulator/Connections/NG911/Connections911.cpp
@@ -106,7 +106,7 @@ bool Connections911::erasePSAP(AllVertices &vertices, Layout &layout)
 
    // Find all psaps
    for (int i = 0; i < numVertices; i++) {
-      if (layout.vertexTypeMap_[i] == vertexType::PSAP) {
+      if (layout.getVertices().vertexTypeMap_[i] == vertexType::PSAP) {
          psaps.push_back(i);
       }
    }
@@ -150,14 +150,14 @@ bool Connections911::erasePSAP(AllVertices &vertices, Layout &layout)
          edges_->eraseEdge(destVertex, iEdg);
 
          // Identify all psap-less callers
-         if (layout.vertexTypeMap_[srcVertex] == vertexType::CALR) {
+         if (layout.getVertices().vertexTypeMap_[srcVertex] == vertexType::CALR) {
             callersToReroute.push_back(srcVertex);
          }
 
          // Identify all psap-less responders
-         if (layout.vertexTypeMap_[destVertex] == vertexType::LAW
-             || layout.vertexTypeMap_[destVertex] == vertexType::FIRE
-             || layout.vertexTypeMap_[destVertex] == vertexType::EMS) {
+         if (layout.getVertices().vertexTypeMap_[destVertex] == vertexType::LAW
+             || layout.getVertices().vertexTypeMap_[destVertex] == vertexType::FIRE
+             || layout.getVertices().vertexTypeMap_[destVertex] == vertexType::EMS) {
             respsToReroute.push_back(destVertex);
          }
       }
@@ -166,7 +166,7 @@ bool Connections911::erasePSAP(AllVertices &vertices, Layout &layout)
    if (changesMade) {
       // This is here so that we don't delete the vertex if we can't find any edges
       verticesErased_.push_back(randPSAP);
-      layout.vertexTypeMap_[randPSAP] = vertexType::VTYPE_UNDEF;
+      layout.getVertices().vertexTypeMap_[randPSAP] = vertexType::VTYPE_UNDEF;
    }
 
    // Failsafe
@@ -243,9 +243,9 @@ bool Connections911::eraseRESP(AllVertices &vertices, Layout &layout)
 
    // Find all resps
    for (int i = 0; i < numVertices; i++) {
-      if (layout.vertexTypeMap_[i] == vertexType::LAW
-          || layout.vertexTypeMap_[i] == vertexType::FIRE
-          || layout.vertexTypeMap_[i] == vertexType::EMS) {
+      if (layout.getVertices().vertexTypeMap_[i] == vertexType::LAW
+          || layout.getVertices().vertexTypeMap_[i] == vertexType::FIRE
+          || layout.getVertices().vertexTypeMap_[i] == vertexType::EMS) {
          resps.push_back(i);
       }
    }
@@ -288,7 +288,7 @@ bool Connections911::eraseRESP(AllVertices &vertices, Layout &layout)
    if (changesMade) {
       // This is here so that we don't delete the vertex if we can't find any edges
       verticesErased_.push_back(randRESP);
-      layout.vertexTypeMap_[randRESP] = vertexType::VTYPE_UNDEF;
+      layout.getVertices().vertexTypeMap_[randRESP] = vertexType::VTYPE_UNDEF;
    }
 
    return changesMade;
diff --git a/Simulator/Connections/Neuro/ConnGrowth_d.cpp b/Simulator/Connections/Neuro/ConnGrowth_d.cpp
index 1854bfe83..c1b49a20b 100644
--- a/Simulator/Connections/Neuro/ConnGrowth_d.cpp
+++ b/Simulator/Connections/Neuro/ConnGrowth_d.cpp
@@ -59,7 +59,7 @@ void ConnGrowth::updateEdgesWeights(int numVertices, AllVertices &vertices, AllE
 
    HANDLE_ERROR(cudaMemcpy(W_d, W_h, W_d_size, cudaMemcpyHostToDevice));
 
-   HANDLE_ERROR(cudaMemcpy(neuronTypeMapD, layout.vertexTypeMap_.data(),
+   HANDLE_ERROR(cudaMemcpy(neuronTypeMapD, layout.getVertices().vertexTypeMap_.data(),
                            simulator.getTotalVertices() * sizeof(vertexType),
                            cudaMemcpyHostToDevice));
 
diff --git a/Simulator/Layouts/Layout.cpp b/Simulator/Layouts/Layout.cpp
index 359980e04..533106c55 100644
--- a/Simulator/Layouts/Layout.cpp
+++ b/Simulator/Layouts/Layout.cpp
@@ -12,8 +12,6 @@
 #include "OperationManager.h"
 #include "ParameterManager.h"
 #include "ParseParamError.h"
-#include "RecordableBase.h"
-#include "Simulator.h"
 #include "Util.h"
 
 /// Constructor
@@ -83,59 +81,23 @@ void Layout::registerGraphProperties()
 
 void Layout::registerHistoryVariables()
 {
-   // Register vertex type map
-   Recorder &recorder = Simulator::getInstance().getModel().getRecorder();
-   recorder.registerVariable("vertexTypeMap", vertexTypeMap_, Recorder::UpdatedType::CONSTANT);
 }
 
-
 /// Setup the internal structure of the class.
 /// Allocate memories to store all layout state, no sequential dependency in this method
 void Layout::setup()
 {
    dist2_ = CompleteMatrix(MATRIX_TYPE, MATRIX_INIT, numVertices_, numVertices_);
    dist_ = CompleteMatrix(MATRIX_TYPE, MATRIX_INIT, numVertices_, numVertices_);
-   // Allocation of internal memory
-   vertexTypeMap_.assign(numVertices_, vertexType::VTYPE_UNDEF);
 }
 
 
-/// Prints out all parameters to logging file. Registered to OperationManager as Operation::printParameters
-void Layout::printParameters() const
-{
-   GraphManager<NeuralVertexProperties>::VertexIterator vi, vi_end;
-   GraphManager<NeuralVertexProperties> &gm = GraphManager<NeuralVertexProperties>::getInstance();
-   stringstream output;
-   output << "\nLAYOUT PARAMETERS" << endl;
-   output << "\tEndogenously active neuron positions: ";
-
-   for (boost::tie(vi, vi_end) = gm.vertices(); vi != vi_end; ++vi) {
-      assert(*vi < numVertices_);
-      if (gm[*vi].active) {
-         output << *vi << " ";
-      }
-   }
-   output << endl;
-
-   output << "\tInhibitory neuron positions: ";
-
-   for (boost::tie(vi, vi_end) = gm.vertices(); vi != vi_end; ++vi) {
-      assert(*vi < numVertices_);
-      if (gm[*vi].type == "INH") {
-         output << *vi << " ";
-      }
-   }
-   output << endl;
-
-   LOG4CPLUS_DEBUG(fileLogger_, output.str());
-}
-
 /// Creates a vertex type map.
 /// @param  numVertices number of the vertices to have in the type map.
 void Layout::generateVertexTypeMap()
 {
    DEBUG(cout << "\nInitializing vertex type map: VTYPE_UNDEF" << endl;);
-   vertexTypeMap_.assign(numVertices_, vertexType::VTYPE_UNDEF);
+   getVertices().vertexTypeMap_.assign(numVertices_, vertexType::VTYPE_UNDEF);
 }
 
 void Layout::initStarterMap()
diff --git a/Simulator/Layouts/Layout.h b/Simulator/Layouts/Layout.h
index d604bf2fc..6268f77e8 100644
--- a/Simulator/Layouts/Layout.h
+++ b/Simulator/Layouts/Layout.h
@@ -14,7 +14,6 @@
 #pragma once
 
 #include "AllVertices.h"
-#include "RecordableVector.h"
 #include "Utils/Global.h"
 #include <iostream>
 #include <log4cplus/loggingmacros.h>
@@ -49,8 +48,9 @@ class Layout {
    /// Load member variables from configuration files. Registered to OperationManager as Operation::loadParameters
    virtual void loadParameters();
 
-   /// Prints out all parameters to logging file. Registered to OperationManager as Operation::printParameters
-   virtual void printParameters() const;
+   /// Prints out model-specific parameters to the logging file. Registered to OperationManager as
+   /// Operation::printParameters. Implemented only on concrete layouts (same pattern as loadParameters).
+   virtual void printParameters() const = 0;
 
    /// Creates a neurons type map
    virtual void generateVertexTypeMap();
@@ -71,11 +71,6 @@ class Layout {
 
    CompleteMatrix dist_;   ///< The true inter-neuron distance.
 
-   vector<int>
-      probedVertexList_;   ///< Probed neurons list. // ToDo: Move this to Hdf5 recorder once its implemented in project -chris
-
-   RecordableVector<vertexType> vertexTypeMap_;   ///< The vertex type mao, (INH, EXC).
-
    ///  Cereal serialization method
    template <class Archive> void serialize(Archive &archive);
 
@@ -90,7 +85,6 @@ class Layout {
 ///  Cereal serialization method
 template <class Archive> void Layout::serialize(Archive &archive)
 {
-   archive(cereal::make_nvp("vertexTypeMap", vertexTypeMap_), cereal::make_nvp("dist2", dist2_),
-           cereal::make_nvp("dist", dist_), cereal::make_nvp("probedVertexList", probedVertexList_),
+   archive(cereal::make_nvp("dist2", dist2_), cereal::make_nvp("dist", dist_),
            cereal::make_nvp("vertices", vertices_), cereal::make_nvp("numVertices", numVertices_));
 }
diff --git a/Simulator/Layouts/NG911/Layout911.cpp b/Simulator/Layouts/NG911/Layout911.cpp
index d024e2ea1..69dd0c96f 100644
--- a/Simulator/Layouts/NG911/Layout911.cpp
+++ b/Simulator/Layouts/NG911/Layout911.cpp
@@ -98,12 +98,34 @@ void Layout911::generateVertexTypeMap()
    // Add all vertices
    GraphManager<NG911VertexProperties>::VertexIterator vi, vi_end;
    GraphManager<NG911VertexProperties> &gm = GraphManager<NG911VertexProperties>::getInstance();
+   callerVertexList_.clear();
+   psapVertexList_.clear();
+   responderVertexList_.clear();
+
    LOG4CPLUS_DEBUG(fileLogger_, "\nvertices in graph: " << gm.numVertices());
    for (boost::tie(vi, vi_end) = gm.vertices(); vi != vi_end; ++vi) {
       assert(*vi < numVertices_);
-      vertexTypeMap_[*vi] = vTypeMap[gm[*vi].type];
+      vertexType vt = vTypeMap[gm[*vi].type];
+      getVertices().vertexTypeMap_[*vi] = vt;
       vTypeCount[gm[*vi].type] += 1;
+
+      switch (vt) {
+         case vertexType::CALR:
+            callerVertexList_.push_back(*vi);
+            break;
+         case vertexType::PSAP:
+            psapVertexList_.push_back(*vi);
+            break;
+         case vertexType::LAW:
+         case vertexType::FIRE:
+         case vertexType::EMS:
+            responderVertexList_.push_back(*vi);
+            break;
+         default:
+            break;
+      }
    }
+   numCallerVertices_ = static_cast<BGSIZE>(callerVertexList_.size());
 
    LOG4CPLUS_DEBUG(fileLogger_, "\nVERTEX TYPE MAP"
                                    << endl
@@ -120,29 +142,24 @@ void Layout911::generateVertexTypeMap()
 // Returns the type of synapse at the given coordinates
 edgeType Layout911::edgType(int srcVertex, int destVertex)
 {
-   if (vertexTypeMap_[srcVertex] == vertexType::CALR
-       && vertexTypeMap_[destVertex] == vertexType::PSAP)
+   auto &vtypes = getVertices().vertexTypeMap_;
+   if (vtypes[srcVertex] == vertexType::CALR && vtypes[destVertex] == vertexType::PSAP)
       return edgeType::CP;
-   else if (vertexTypeMap_[srcVertex] == vertexType::PSAP
-            && (vertexTypeMap_[destVertex] == vertexType::LAW
-                || vertexTypeMap_[destVertex] == vertexType::FIRE
-                || vertexTypeMap_[destVertex] == vertexType::EMS))
+   else if (vtypes[srcVertex] == vertexType::PSAP
+            && (vtypes[destVertex] == vertexType::LAW || vtypes[destVertex] == vertexType::FIRE
+                || vtypes[destVertex] == vertexType::EMS))
       return edgeType::PR;
-   else if (vertexTypeMap_[srcVertex] == vertexType::PSAP
-            && vertexTypeMap_[destVertex] == vertexType::CALR)
+   else if (vtypes[srcVertex] == vertexType::PSAP && vtypes[destVertex] == vertexType::CALR)
       return edgeType::PC;
-   else if (vertexTypeMap_[srcVertex] == vertexType::PSAP
-            && vertexTypeMap_[destVertex] == vertexType::PSAP)
+   else if (vtypes[srcVertex] == vertexType::PSAP && vtypes[destVertex] == vertexType::PSAP)
       return edgeType::PP;
-   else if ((vertexTypeMap_[srcVertex] == vertexType::LAW
-             || vertexTypeMap_[destVertex] == vertexType::FIRE
-             || vertexTypeMap_[destVertex] == vertexType::EMS)
-            && vertexTypeMap_[destVertex] == vertexType::PSAP)
+   else if ((vtypes[srcVertex] == vertexType::LAW || vtypes[srcVertex] == vertexType::FIRE
+             || vtypes[srcVertex] == vertexType::EMS)
+            && vtypes[destVertex] == vertexType::PSAP)
       return edgeType::RP;
-   else if ((vertexTypeMap_[srcVertex] == vertexType::LAW
-             || vertexTypeMap_[destVertex] == vertexType::FIRE
-             || vertexTypeMap_[destVertex] == vertexType::EMS)
-            && vertexTypeMap_[destVertex] == vertexType::CALR)
+   else if ((vtypes[srcVertex] == vertexType::LAW || vtypes[srcVertex] == vertexType::FIRE
+             || vtypes[srcVertex] == vertexType::EMS)
+            && vtypes[destVertex] == vertexType::CALR)
       return edgeType::RC;
    else
       return edgeType::ETYPE_UNDEF;
diff --git a/Simulator/Layouts/NG911/Layout911.h b/Simulator/Layouts/NG911/Layout911.h
index 3b912391a..c2f80ed88 100644
--- a/Simulator/Layouts/NG911/Layout911.h
+++ b/Simulator/Layouts/NG911/Layout911.h
@@ -83,6 +83,14 @@ class Layout911 : public Layout {
    /// @return The distance between the given vertex and the (x, y) coordinates of a point
    double getDistance(int vertexId, double x, double y);
 
+   /// Caller vertex count (set during \ref generateVertexTypeMap).
+   BGSIZE numCallerVertices_ = 0;
+
+   /// Vertex indices grouped by NG911 role; filled in \ref generateVertexTypeMap.
+   vector<int> callerVertexList_;
+   vector<int> psapVertexList_;
+   vector<int> responderVertexList_;
+
    DeviceVector<BGFLOAT> xloc_;
    DeviceVector<BGFLOAT> yloc_;
 };
diff --git a/Simulator/Layouts/Neuro/LayoutNeuro.cpp b/Simulator/Layouts/Neuro/LayoutNeuro.cpp
index 3c2c14ea3..f5e5b6473 100644
--- a/Simulator/Layouts/Neuro/LayoutNeuro.cpp
+++ b/Simulator/Layouts/Neuro/LayoutNeuro.cpp
@@ -12,6 +12,7 @@
 #include "ParameterManager.h"
 #include "ParseParamError.h"
 #include "Util.h"
+#include <sstream>
 
 // TODO: I don't think that either of the constructor or destructor is needed here
 LayoutNeuro::LayoutNeuro() : Layout()
@@ -87,9 +88,23 @@ void LayoutNeuro::registerHistoryVariables()
 ///  Registered to OperationManager as Operation::printParameters
 void LayoutNeuro::printParameters() const
 {
-   Layout::printParameters();
+   stringstream output;
+   output << "\nLAYOUT PARAMETERS" << endl;
+   output << "\tEndogenously active neuron positions: ";
+   for (int idx : endogenouslyActiveNeuronList_) {
+      output << idx << " ";
+   }
+   output << endl;
+
+   output << "\tInhibitory neuron positions: ";
+   for (int idx : inhibitoryNeuronLayout_) {
+      output << idx << " ";
+   }
+   output << endl;
+
+   output << "\n\tLayout type: LayoutNeuro" << endl << endl;
 
-   LOG4CPLUS_DEBUG(fileLogger_, "\n\tLayout type: LayoutNeuro" << endl << endl);
+   LOG4CPLUS_DEBUG(fileLogger_, output.str());
 }
 
 ///  Creates a randomly ordered distribution with the specified numbers of vertex types.
@@ -99,9 +114,11 @@ void LayoutNeuro::generateVertexTypeMap()
 {
    LOG4CPLUS_DEBUG(fileLogger_, "\nInitializing vertex type map" << endl);
 
-   int numInhibitoryNeurons;
+   int numInhibitoryNeurons = 0;
    int numExcititoryNeurons;
 
+   inhibitoryNeuronLayout_.clear();
+
    // Set Neuron Type from GraphML File
    GraphManager<NeuralVertexProperties>::VertexIterator vi, vi_end;
    GraphManager<NeuralVertexProperties> &gm = GraphManager<NeuralVertexProperties>::getInstance();
@@ -109,12 +126,13 @@ void LayoutNeuro::generateVertexTypeMap()
    for (boost::tie(vi, vi_end) = gm.vertices(); vi != vi_end; ++vi) {
       assert(*vi < numVertices_);
       if (gm[*vi].type == "INH") {
-         vertexTypeMap_[*vi] = vertexType::INH;
+         getVertices().vertexTypeMap_[*vi] = vertexType::INH;
+         inhibitoryNeuronLayout_.push_back(*vi);
          numInhibitoryNeurons++;
       }
       // Default Type is Excitatory
       else {
-         vertexTypeMap_[*vi] = vertexType::EXC;
+         getVertices().vertexTypeMap_[*vi] = vertexType::EXC;
       }
    }
 
@@ -133,6 +151,9 @@ void LayoutNeuro::generateVertexTypeMap()
 ///  @param  numVertices number of vertices to have in the map.
 void LayoutNeuro::initStarterMap()
 {
+   endogenouslyActiveNeuronList_.clear();
+   numEndogenouslyActiveNeurons_ = 0;
+
    // Set Neuron Activity from GraphML File
    GraphManager<NeuralVertexProperties>::VertexIterator vi, vi_end;
    GraphManager<NeuralVertexProperties> &gm = GraphManager<NeuralVertexProperties>::getInstance();
@@ -143,6 +164,7 @@ void LayoutNeuro::initStarterMap()
       assert(*vi < numVertices_);
       if (gm[*vi].active) {
          starterMap_[*vi] = true;
+         endogenouslyActiveNeuronList_.push_back(*vi);
          numEndogenouslyActiveNeurons_++;
       }
    }
@@ -155,17 +177,14 @@ void LayoutNeuro::initStarterMap()
 ///  @return type of the synapse.
 edgeType LayoutNeuro::edgType(int srcVertex, int destVertex)
 {
-   if (vertexTypeMap_[srcVertex] == vertexType::INH
-       && vertexTypeMap_[destVertex] == vertexType::INH)
+   auto &vtypes = getVertices().vertexTypeMap_;
+   if (vtypes[srcVertex] == vertexType::INH && vtypes[destVertex] == vertexType::INH)
       return edgeType::II;
-   else if (vertexTypeMap_[srcVertex] == vertexType::INH
-            && vertexTypeMap_[destVertex] == vertexType::EXC)
+   else if (vtypes[srcVertex] == vertexType::INH && vtypes[destVertex] == vertexType::EXC)
       return edgeType::IE;
-   else if (vertexTypeMap_[srcVertex] == vertexType::EXC
-            && vertexTypeMap_[destVertex] == vertexType::INH)
+   else if (vtypes[srcVertex] == vertexType::EXC && vtypes[destVertex] == vertexType::INH)
       return edgeType::EI;
-   else if (vertexTypeMap_[srcVertex] == vertexType::EXC
-            && vertexTypeMap_[destVertex] == vertexType::EXC)
+   else if (vtypes[srcVertex] == vertexType::EXC && vtypes[destVertex] == vertexType::EXC)
       return edgeType::EE;
 
    return edgeType::ETYPE_UNDEF;
diff --git a/Simulator/Layouts/Neuro/LayoutNeuro.h b/Simulator/Layouts/Neuro/LayoutNeuro.h
index b31e2f21a..2c46c3b09 100644
--- a/Simulator/Layouts/Neuro/LayoutNeuro.h
+++ b/Simulator/Layouts/Neuro/LayoutNeuro.h
@@ -70,6 +70,15 @@ class LayoutNeuro : public Layout {
 
    BGSIZE numEndogenouslyActiveNeurons_;   ///< Number of endogenously active neurons.
 
+   /// Indices of endogenously active (starter) neurons; filled in \ref initStarterMap.
+   vector<int> endogenouslyActiveNeuronList_;
+
+   /// Indices of inhibitory neurons; filled in \ref generateVertexTypeMap.
+   vector<int> inhibitoryNeuronLayout_;
+
+   /// Indices of probed neurons for recording (HDF5 / future recorders).
+   vector<int> probedVertexList_;
+
    ///  Cereal serialization method
    template <class Archive> void serialize(Archive &archive);
 };
@@ -81,5 +90,8 @@ template <class Archive> void LayoutNeuro::serialize(Archive &archive)
 {
    archive(cereal::virtual_base_class<Layout>(this), cereal::make_nvp("xloc", xloc_),
            cereal::make_nvp("yloc", yloc_), cereal::make_nvp("starterMap", starterMap_),
-           cereal::make_nvp("numEndogenouslyActiveNeurons", numEndogenouslyActiveNeurons_));
+           cereal::make_nvp("numEndogenouslyActiveNeurons", numEndogenouslyActiveNeurons_),
+           cereal::make_nvp("endogenouslyActiveNeuronList", endogenouslyActiveNeuronList_),
+           cereal::make_nvp("inhibitoryNeuronLayout", inhibitoryNeuronLayout_),
+           cereal::make_nvp("probedVertexList", probedVertexList_));
 }
diff --git a/Simulator/Recorders/NG911/Xml911Recorder.cpp b/Simulator/Recorders/NG911/Xml911Recorder.cpp
index cc7535cfe..f7d058be3 100644
--- a/Simulator/Recorders/NG911/Xml911Recorder.cpp
+++ b/Simulator/Recorders/NG911/Xml911Recorder.cpp
@@ -42,7 +42,8 @@ void Xml911Recorder::saveSimData()
 
    for (int i = 0; i < Simulator::getInstance().getTotalVertices(); i++) {
       vertexTypes[i]
-         = static_cast<BGFLOAT>(Simulator::getInstance().getModel().getLayout().vertexTypeMap_[i]);
+         = static_cast<BGFLOAT>(
+            Simulator::getInstance().getModel().getLayout().getVertices().vertexTypeMap_[i]);
       oldTypes[i] = static_cast<BGFLOAT>(conns911.oldTypeMap_[i]);
    }
 
diff --git a/Simulator/Utils/Inputs/SInputPoisson.cpp b/Simulator/Utils/Inputs/SInputPoisson.cpp
index 3878f7352..61a5a1695 100644
--- a/Simulator/Utils/Inputs/SInputPoisson.cpp
+++ b/Simulator/Utils/Inputs/SInputPoisson.cpp
@@ -67,7 +67,7 @@ SInputPoisson::SInputPoisson(TiXmlElement *parms) :
                TiXmlDocument simDoc(maskNListFileName.c_str());
                if (!simDoc.LoadFile()) {
                   cerr << "Failed loading positions of stimulus input mask neurons list file "
-                       << maskNListFileName << ":" << "\n\t" << simDoc.ErrorDesc() << endl;
+                       << maskNListFileName << ":\n\t" << simDoc.ErrorDesc() << endl;
                   cerr << " error: " << simDoc.ErrorRow() << ", " << simDoc.ErrorCol() << endl;
                   break;
                }
@@ -107,10 +107,11 @@ void SInputPoisson::init()
    for (int neuronIndex = 0; neuronIndex < Simulator::getInstance().getTotalVertices();
         neuronIndex++) {
       edgeType type;
-      if (Simulator::getInstance().getModel().getLayout().vertexTypeMap_[neuronIndex] == INH)
-         type = EI;
+      if (Simulator::getInstance().getModel().getLayout().getVertices().vertexTypeMap_[neuronIndex]
+          == vertexType::INH)
+         type = edgeType::EI;
       else
-         type = EE;
+         type = edgeType::EE;
 
       BGSIZE iEdg = Simulator::getInstance().getMaxEdgesPerVertex() * neuronIndex;
 
diff --git a/Simulator/Vertices/AllVertices.cpp b/Simulator/Vertices/AllVertices.cpp
index db82979b7..da3a7b769 100644
--- a/Simulator/Vertices/AllVertices.cpp
+++ b/Simulator/Vertices/AllVertices.cpp
@@ -8,6 +8,7 @@
 
 #include "AllVertices.h"
 #include "OperationManager.h"
+#include "Recorder.h"
 
 // Utility function to convert a vertexType into a string.
 // MODEL INDEPENDENT FUNCTION NMV-BEGIN {
@@ -79,6 +80,13 @@ AllVertices::AllVertices() : size_(0)
 void AllVertices::setupVertices()
 {
    size_ = Simulator::getInstance().getTotalVertices();
+   vertexTypeMap_.assign(size_, vertexType::VTYPE_UNDEF);
+}
+
+void AllVertices::registerHistoryVariables()
+{
+   Recorder &recorder = Simulator::getInstance().getModel().getRecorder();
+   recorder.registerVariable("vertexTypeMap", vertexTypeMap_, Recorder::UpdatedType::CONSTANT);
 }
 
 ///  Prints out all parameters of the vertices to logging file.
diff --git a/Simulator/Vertices/AllVertices.h b/Simulator/Vertices/AllVertices.h
index 2316cf920..050002736 100644
--- a/Simulator/Vertices/AllVertices.h
+++ b/Simulator/Vertices/AllVertices.h
@@ -26,8 +26,9 @@ using namespace std;
 #include "AllEdges.h"
 #include "BGTypes.h"
 #include "Core/EdgeIndexMap.h"
-#include "Layout.h"
+#include "RecordableVector.h"
 #include "Simulator.h"
+#include "VertexType.h"
 #include <iostream>
 #include <log4cplus/loggingmacros.h>
 // cereal
@@ -88,11 +89,16 @@ class AllVertices {
    /// Helper function for recorder to register spike history variables for all vertices.
    /// Option 1: Register vertex information in vertexEvents_ one by one.
    /// Option 2: Register a vector of EventBuffer variables.
-   virtual void registerHistoryVariables() = 0;
+   /// Base implementation registers \c vertexTypeMap_; subclasses should call
+   /// \c AllVertices::registerHistoryVariables() first when overriding.
+   virtual void registerHistoryVariables();
 
    ///  Cereal serialization method
    template <class Archive> void serialize(Archive &archive);
 
+   /// Excitatory / inhibitory (neuro) or NG911 role per vertex index.
+   RecordableVector<vertexType> vertexTypeMap_;
+
 protected:
    ///  Total number of vertices.
    int size_;
@@ -179,5 +185,5 @@ struct AllVerticesDeviceProperties {};
 
 template <class Archive> void AllVertices::serialize(Archive &archive)
 {
-   archive(cereal::make_nvp("size", size_));
+   archive(cereal::make_nvp("size", size_), cereal::make_nvp("vertexTypeMap", vertexTypeMap_));
 }
\ No newline at end of file
diff --git a/Simulator/Vertices/NG911/All911Vertices.cpp b/Simulator/Vertices/NG911/All911Vertices.cpp
index 705bab50f..b0b142537 100644
--- a/Simulator/Vertices/NG911/All911Vertices.cpp
+++ b/Simulator/Vertices/NG911/All911Vertices.cpp
@@ -158,7 +158,7 @@ void All911Vertices::loadEpochInputsToVertices(uint64_t currentStep, uint64_t en
    // Load all the calls into the Caller Regions queue by getting the input events
    // from the InputManager.
    for (int idx = 0; idx < simulator.getTotalVertices(); ++idx) {
-      if (layout.vertexTypeMap_[idx] == vertexType::CALR) {
+      if (layout.getVertices().vertexTypeMap_[idx] == vertexType::CALR) {
          // If this is a Caller Region get all calls scheduled for the current epoch,
          // loading them into the aproppriate index of the vertexQueues_ vector
          inputManager_.getEvents(idx, currentStep, endStep, vertexQueues_[idx]);
@@ -168,6 +168,8 @@ void All911Vertices::loadEpochInputsToVertices(uint64_t currentStep, uint64_t en
 
 void All911Vertices::registerHistoryVariables()
 {
+   AllVertices::registerHistoryVariables();
+
    Recorder &recorder = Simulator::getInstance().getModel().getRecorder();
 
    // Registering the following variables to be recorded
@@ -243,7 +245,8 @@ void All911Vertices::integrateVertexInputs(AllEdges &edges, EdgeIndexMap &edgeIn
       int start = edgeIndexMap.incomingEdgeBegin_[vertex];
       int count = edgeIndexMap.incomingEdgeCount_[vertex];
 
-      if (simulator.getModel().getLayout().vertexTypeMap_[vertex] == vertexType::CALR) {
+      if (simulator.getModel().getLayout().getVertices().vertexTypeMap_[vertex]
+          == vertexType::CALR) {
          continue;   // TODO911: Caller Regions will have different behaviour
       }
 
@@ -315,13 +318,13 @@ void All911Vertices::advanceVertices(AllEdges &edges, const EdgeIndexMap &edgeIn
 
    // Advance vertices
    for (int vertex = 0; vertex < simulator.getTotalVertices(); ++vertex) {
-      if (layout.vertexTypeMap_[vertex] == vertexType::CALR) {
+      if (layout.getVertices().vertexTypeMap_[vertex] == vertexType::CALR) {
          advanceCALR(vertex, edges911, edgeIndexMap);
-      } else if (layout.vertexTypeMap_[vertex] == vertexType::PSAP) {
+      } else if (layout.getVertices().vertexTypeMap_[vertex] == vertexType::PSAP) {
          advancePSAP(vertex, edges911, edgeIndexMap);
-      } else if (layout.vertexTypeMap_[vertex] == vertexType::EMS
-                 || layout.vertexTypeMap_[vertex] == vertexType::FIRE
-                 || layout.vertexTypeMap_[vertex] == vertexType::LAW) {
+      } else if (layout.getVertices().vertexTypeMap_[vertex] == vertexType::EMS
+                 || layout.getVertices().vertexTypeMap_[vertex] == vertexType::FIRE
+                 || layout.getVertices().vertexTypeMap_[vertex] == vertexType::LAW) {
          advanceRESP(vertex, edges911, edgeIndexMap);
       }
    }
@@ -624,7 +627,7 @@ BGSIZE All911Vertices::getEdgeToClosestResponder(const Call &call, BGSIZE vertex
       assert(edges911.inUse_[outEdg]);   // Edge must be in use
 
       BGSIZE dstVertex = edges911.destVertexIndex_[outEdg];
-      if (layout911.vertexTypeMap_[dstVertex] == requiredType) {
+      if (layout911.getVertices().vertexTypeMap_[dstVertex] == requiredType) {
          double distance = layout911.getDistance(dstVertex, call.x, call.y);
 
          if (distance < minDistance) {
@@ -637,7 +640,7 @@ BGSIZE All911Vertices::getEdgeToClosestResponder(const Call &call, BGSIZE vertex
 
    // We must have found the closest responder of the right type
    assert(minDistance < numeric_limits<double>::max());
-   assert(layout911.vertexTypeMap_[resp] == requiredType);
+   assert(layout911.getVertices().vertexTypeMap_[resp] == requiredType);
    return respEdge;
 }
 #endif
\ No newline at end of file
diff --git a/Simulator/Vertices/Neuro/AllIFNeurons.cpp b/Simulator/Vertices/Neuro/AllIFNeurons.cpp
index 85057b0b2..09e5eac3f 100644
--- a/Simulator/Vertices/Neuro/AllIFNeurons.cpp
+++ b/Simulator/Vertices/Neuro/AllIFNeurons.cpp
@@ -128,7 +128,7 @@ void AllIFNeurons::createNeuron(int i, Layout &layout)
 
    initNeuronConstsFromParamValues(i, Simulator::getInstance().getDeltaT());
 
-   switch (layoutNeuro.vertexTypeMap_[i]) {
+   switch (layout.getVertices().vertexTypeMap_[i]) {
       case vertexType::INH:
          LOG4CPLUS_DEBUG(vertexLogger_, "Setting inhibitory neuron: " << i);
          // set inhibitory absolute refractory period
@@ -142,8 +142,8 @@ void AllIFNeurons::createNeuron(int i, Layout &layout)
          break;
 
       default:
-         LOG4CPLUS_DEBUG(vertexLogger_,
-                         "ERROR: unknown neuron type: " << layout.vertexTypeMap_[i] << "@" << i);
+         LOG4CPLUS_DEBUG(vertexLogger_, "ERROR: unknown neuron type: "
+                                           << layout.getVertices().vertexTypeMap_[i] << "@" << i);
          assert(false);
          break;
    }
diff --git a/Simulator/Vertices/Neuro/AllIZHNeurons.cpp b/Simulator/Vertices/Neuro/AllIZHNeurons.cpp
index 50d368658..72d75696e 100644
--- a/Simulator/Vertices/Neuro/AllIZHNeurons.cpp
+++ b/Simulator/Vertices/Neuro/AllIZHNeurons.cpp
@@ -72,7 +72,7 @@ void AllIZHNeurons::createNeuron(int i, Layout &layout)
    AllIFNeurons::createNeuron(i, layout);
 
    // TODO: we may need another distribution mode besides flat distribution
-   if (layout.vertexTypeMap_[i] == vertexType::EXC) {
+   if (layout.getVertices().vertexTypeMap_[i] == vertexType::EXC) {
       // excitatory neuron
       Aconst_[i] = initRNG.inRange(excAconst_[0], excAconst_[1]);
       Bconst_[i] = initRNG.inRange(excBconst_[0], excBconst_[1]);
diff --git a/Simulator/Vertices/Neuro/AllSpikingNeurons.cpp b/Simulator/Vertices/Neuro/AllSpikingNeurons.cpp
index a2769fa0a..c8daf29f1 100644
--- a/Simulator/Vertices/Neuro/AllSpikingNeurons.cpp
+++ b/Simulator/Vertices/Neuro/AllSpikingNeurons.cpp
@@ -28,6 +28,8 @@ void AllSpikingNeurons::setupVertices()
 ///  Option 2: Register a vector of EventBuffer variables.
 void AllSpikingNeurons::registerHistoryVariables()
 {
+   AllVertices::registerHistoryVariables();
+
    Recorder &recorder = Simulator::getInstance().getModel().getRecorder();
    string baseName = "Neuron_";