diff --git a/elements/neuron/presynapse.md b/elements/neuron/presynapse.md
index 089ec84..4886705 100644
--- a/elements/neuron/presynapse.md
+++ b/elements/neuron/presynapse.md
@@ -30,7 +30,7 @@ PRESYNAPSE
 
   expand_comprehension: 
     _Vgcc_pre: TUB [ expand: VGCC_PRE, full: 10x, active: 5x, empty: 2x ]
-    # serve al tuning
+    # il tub serve al tuning
 
   instantiate_tub:
     _Ca2+: TUB [ full: 60x, active: 30x, empty: 0x ]