diff --git a/app/models/map.rb b/app/models/map.rb
index ddcefb86..280fcef3 100644
--- a/app/models/map.rb
+++ b/app/models/map.rb
@@ -84,14 +84,15 @@ class Map < ActiveRecord::Base
 
   def to_csv(options = {})
     CSV.generate(options) do |csv|
-      csv << ["id", "name", "metacode", "user.name", "permission"]
+      csv << ["id", "name", "metacode", "user.name", "permission", "synapses"]
       self.topics.each do |topic|
         csv << [
           topic.id,
           topic.name,
           topic.metacode.name,
           topic.user.name,
-          topic.permission
+          topic.permission,
+          topic.synapses_csv("text")
         ]
       end
     end
diff --git a/app/models/topic.rb b/app/models/topic.rb
index 7e5fff94..b4218202 100644
--- a/app/models/topic.rb
+++ b/app/models/topic.rb
@@ -90,6 +90,37 @@ class Topic < ActiveRecord::Base
   	end
   	return result
   end
+
+  def synapses_csv(output_format = "array")
+    output = []
+    self.synapses.each do |synapse|
+      if synapse.category == "from-to"
+        if synapse.node1_id == self.id
+          output << synapse.node1_id.to_s + "->" + synapse.node2_id.to_s
+        elsif synapse.node2_id == self.id
+          output << synapse.node2_id.to_s + "<-" + synapse.node1_id.to_s
+        else
+          abort("invalid synapse on topic in synapse_csv")
+        end
+      elsif synapse.category == "both"
+        if synapse.node1_id == self.id
+          output << synapse.node1_id.to_s + "<->" + synapse.node2_id.to_s
+        elsif synapse.node2_id == self.id
+          output << synapse.node2_id.to_s + "<->" + synapse.node1_id.to_s
+        else
+          abort("invalid synapse on topic in synapse_csv")
+        end
+      end
+    end
+    if output_format == "array"
+      return output
+    elsif output_format == "text"
+      return output.join("; ")
+    else
+      abort("invalid argument to synapses_csv")
+    end
+    return output
+  end
   
   ##### PERMISSIONS ######
   
diff --git a/app/views/maps/show.xls.erb b/app/views/maps/show.xls.erb
index f455ff1d..55b89552 100644
--- a/app/views/maps/show.xls.erb
+++ b/app/views/maps/show.xls.erb
@@ -5,6 +5,7 @@
     <th>Metacode</th>
     <th>Username</th>
     <th>Permission</th>
+    <th>Synapses</th>
   </tr>
   <% @map.topics.each do |topic| %>
   <tr>
@@ -13,6 +14,9 @@
     <td><%= topic.metacode.name %></td>
     <td><%= topic.user.name %></td>
     <td><%= topic.permission %></td>
+    <% topic.synapses_csv.each do |s_text| %>
+      <td><%= s_text %></td>
+    <% end %>
   </tr>
   <% end %>
 </table>