diff --git a/Editor/ClusterEditor.cs b/Editor/ClusterEditor.cs
index e3ed2ef..3bc2791 100644
--- a/Editor/ClusterEditor.cs
+++ b/Editor/ClusterEditor.cs
@@ -186,7 +186,7 @@ namespace NanoBrain.Unity {
         protected void ClusterInspector(Cluster cluster, ref bool anythingChanged) {
             EditorGUILayout.BeginHorizontal();
 
-            int instanceCount = cluster.instanceCount;
+            int instanceCount = (int)cluster.instanceCount;
             if (instanceCount <= 1) {
                 if (cluster.instances != null && cluster.instances.Length > 1)
                     instanceCount = cluster.instances.Count();
diff --git a/Runtime/Scripts/Core/Cluster.cs b/Runtime/Scripts/Core/Cluster.cs
index 77ed36b..8abf227 100644
--- a/Runtime/Scripts/Core/Cluster.cs
+++ b/Runtime/Scripts/Core/Cluster.cs
@@ -63,7 +63,7 @@ namespace NanoBrain {
         /// </summary>
         /// A cluster is a multi-clsuter when there is more than one instance.
         [SerializeField]
-        public int instanceCount = 1;
+        public uint instanceCount = 1;
         /// <summary>
         /// The mapping from things to cluster instances
         /// </summary>
@@ -89,7 +89,7 @@ namespace NanoBrain {
         /// </summary>
         /// <param name="prefab">The prefab to use</param>
         /// <param name="parent">The cluster in which this new cluster will be placed</param>
-        public Cluster(ClusterPrefab prefab, Cluster parent) {
+        public Cluster(ClusterPrefab prefab, Cluster parent, uint instanceCount = 1) {
             this.prefab = prefab;
             this.version = prefab.version;
             this.name = prefab.name;
@@ -97,6 +97,27 @@ namespace NanoBrain {
             this.parent = parent;
             this.parent?.nuclei.Add(this);
             ClonePrefab();
+
+            if (instanceCount > 1) {
+                Debug.Log($" InstanceCount = {instanceCount}");
+                List<Cluster> siblings = new() { this };
+                for (int instanceIx = 1; instanceIx < instanceCount; instanceIx++) {
+                    // Create another sibling
+                    Cluster sibling = new(prefab, this) {
+                        name = $"{this.baseName}: {instanceIx}",
+                        parent = this.parent,
+                        instanceCount = this.instanceCount,
+                    };
+                    siblings.Add(sibling);
+                    CopyAllExternalReceivers(this, sibling, this);
+                }
+                Cluster[] siblingClusters = siblings.ToArray();
+                foreach (Cluster sibling in siblings) {
+                    sibling.instanceCount = instanceCount;
+                    sibling.instances = siblingClusters;
+                }
+
+            }
         }
 
         /// <summary>
@@ -158,7 +179,12 @@ namespace NanoBrain {
                         if (extPrefab == null)
                             Debug.LogError($"Could not find cluster Resource {synapseData.clusterName}");
                         else {
-                            Cluster extCluster = new Cluster(extPrefab, this);
+                            uint instanceCount = 1;
+                            foreach (ExternalClusterData externalCluster in clusterData.clusters) {
+                                if (externalCluster.name == synapseData.clusterName)
+                                    instanceCount = externalCluster.instanceCount;
+                            }
+                            Cluster extCluster = new Cluster(extPrefab, this, instanceCount);
                             Neuron extNeuron = extCluster.GetNeuron(synapseData.neuronName);
                             extNeuron.AddReceiver(receiver);
                         }