diff --git a/elements/neuron/presynapse.md b/elements/neuron/presynapse.md
index 46e9ba0..bee65f4 100644
--- a/elements/neuron/presynapse.md
+++ b/elements/neuron/presynapse.md
@@ -101,23 +101,23 @@ RELEASE_NT
   
   // ########################## Emit NT, *AP ##########################
 
-  // Devo aggiungere la limitazione dovuta al Glutamate Spillover GluR !!!!
+  // Devo aggiungere la limitazione dovuta al Glutamate Spillover GluR e retro_eCB !!!!
   
-  NTreleaseLow: INSTANTIATE [ snippet: accumulator, event: 12x, cost: 3x, context: *AP ] {
+  NTreleaseLow: INSTANTIATE [ snippet: accumulator, event: 12x, cost: _pre_budget 3x, context: *AP ] {
     hypothesis: _Ca2 mediumness AND _Rrp mediumness AND NOT _pre_budget empty 
-      action: [ _Rrp decrease, _NT increase, _pre_budget decrease ]
+      action: [ _Rrp decrease, _NT increase ]
       else: None
   }
   
-  NTreleaseMedium: INSTANTIATE [ snippet: accumulator, event: 9x, cost: 3x, context: *AP ] {
+  NTreleaseMedium: INSTANTIATE [ snippet: accumulator, event: 9x, cost: _pre_budget 3x, context: *AP ] {
     hypothesis: ( _Ca2 fullness AND _Rrp mediumness ) OR ( _Ca2 mediumness AND _Rrp fullness ) AND NOT _pre_budget empty 
-      action: [ _Rrp decrease, _NT increase, _pre_budget decrease ]
+      action: [ _Rrp decrease, _NT increase ]
       else: None
   }
 
-  NTreleaseHigh: INSTANTIATE [ snippet: accumulator, event: 6x, cost: 3x, context: *AP ] {
+  NTreleaseHigh: INSTANTIATE [ snippet: accumulator, event: 6x, cost: _pre_budget 3x, context: *AP ] {
     hypothesis: _Ca2 fullness AND _Rrp fullness  AND NOT _pre_budget empty
-      action: [ _Rrp decrease, NT increase, _pre_budget decrease ]
+      action: [ _Rrp decrease, NT increase ]
       else: None
   }
 
@@ -137,7 +137,7 @@ TRACE
   
   // Tag se manca pre_budget, ma il rilascio di NT sarebbe stato di beneficio
 
-  Endourance_tag: INSTANTIATE [ snippet: accumulator, event: 12x, cost: 3x, context: *AP ] {
+  Endourance_tag: INSTANTIATE [ snippet: accumulator, event: 12x, cost: 0x, context: *AP ] {
     hypothesis: _pre_budget empty AND NOT deve esserci la possibilita di spikare e altri segnali come NO 
       action: [ _pre_endurance_tag increase ]
       else: None