organism/elements/neuron/postsynapse.md

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include_toc: true
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# postsynapse.md

Qui comprendiamo:

- POSTSYNAPSE: Postsynapse
- POST-AMPA: AMPA receptors (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors)

**Simplified Behaviors**:

— ms:

- NT arrives in cleft → AMPA receptors bind NT (receptor availability constant, no desensitization)
- V_post rises with AMPA conductance, decays passively each ms
- bAP arrives → V_post receives additional depolarisation boost
- NMDA gate checks coincidence: NT_cleft AND V_post both non-zero
- Mg_block_removal = V_post / (V_post + V_NMDA_half) — sigmoid of V_post
- Ca²⁺ enters spine via NMDA: Ca_post += k_NMDA × NT_cleft × Mg_block_removal
- Ca_post decays slowly each ms (single exponential, no pump detail)
- Ca_post_history updated every ms (feeds seconds loop)
- V_post_history updated every ms (retained for reference)

— seconds:

- Ca_post_history mean computed over past 2 s
- eCB synthesised when Ca_post_history mean exceeds eCB threshold
- eCB_level decays when Ca_post_history mean falls below threshold
- eCB_level written → read by presynapse as retrograde brake on VGCCs
- Ca_post_history compared to LTP/LTD thresholds → plasticity tag set

— mins:

- If Plasticity_LTP tagged → AMPA density increases
- If Plasticity_LTD tagged → AMPA density decreases
- AMPA density feeds back into receptor_conductance ceiling for next cycle

---

**G expression**:

```Gen

bAP_ctx
    POSTSYNAPSE (ms)
      -- Ca Influx
      CaNDMAEnterMax: ( active: 2x ) accumulator
      CaNDMAEnterMed: ( active: 4x ) accumulator

NOT bAP_ctx:
    POSTSYNAPSE (ms)
      -- Ca Influx
      CaNDMAEnterMedNotBap: ( active: 4x ) accumulator
      CaNDMAEnterLow: ( active: 12x ) accumulator
      -- Ca Clearence
      CaClearance: ( active: 24x ) accumulator
      -- V Influx
      VPostMax: ( active: 4x ) accumulator ->VPost 
      VPostMed: ( active: 8x ) accumulator ->VPost
      VPostLow: ( active: 16x ) accumulator ->VPost
      -- V Clearence
      VPostClearance: ( active: 18x ) accumulator ~->VPost
    POST-AMPA (ms) ~ NT
        -- Na Influx
        NaAMPAEnterMax: ( active: 2x ) accumulator ~NT
        NaAMPAEnterMed: ( active: 4x ) accumulator ~NT
    POST-NA-CLEAR (ms)
        -- Na Clearence
        NaClearanceHigh: ( active: 4x ) accumulator
        NaClearanceLow: ( active: 16x ) accumulator

TunPossible_ctx
    TUN-POST-AMPA (sec)
      CheckTunPostAmpa: ( active: 60x ) contexting
          TryTunUpPostAmpa_ctx
              PossibleUpPostAmpaTun: ( active: 10x ) accumulator
          TryTunDownPostAmpa_ctx
              PossibleDownPostAmpaTun: ( active: 10x ) accumulator
```

**Tubs:**

- **Na**: Ioni entranti tramite AMPA receptors
- **NT**:
- **Ca2+**: Ioni entranti tramite NMDA
- **VPost**: il voltage che viene sentito in DB
- **eCB**:
- **Nox**:?

---

## POSTSYNAPSE: Comprehension

```Gen
POSTSYNAPSE
 type: comprehension

 expand_comprehension: 
    &POST-AMPA_ALL: POST-AMPA (full: 10x, active: 5x, empty: 2x)
    @: POST-NA-CLEAR (full: 1x, active: 1x, empty: 0x)

 instantiate_container:
    POSTSYNAPSE-BEH []
    TUN-POST-AMPA [pass: POST-AMPA_ALL]
```

### POSTSYNAPSE: Container
```
POSTSYNAPSE-BEH

  type: container

  activity_scope: !DAY

  tub_local:
    - Ca2+ ( full: 60x, active: 30x, empty: 0x )
    - Na ( full: 60x, active: 30x, empty: 0x )
    - Nox ( full: 100x, active: 20x, empty: 0x ) # Nitric Oxide (NO):  A gas that diffuses freely.
    - eCB ( full: 100x, active: 20x, empty: 0x ) # Endocannabinoids (e.g., 2-AG)

 tub_intricated:
  - NT ( contained_by: SYNAPSE )
  - VPost ( contained_by: BD )

 context_intricated:
  - bAp_ctx ( contained_by: SOMA )
```

#### bAp_ctx

![post-ltp-ltd.png](.attachments/post-ltp-ltd.png)


##### CaNDMAEnterMax: ( active: 2x ) accumulator

```Gen
CaNDMAEnterMax: ( active: 2x )
  type: accumulator
  contained_by: POSTSYNAPSE-BEH

  in_context: bAp_ctx
    hypothesis: NOT (Ca2+ full) AND
               (Na fullness OR Na mediumness)
      action: [Ca2+ increase]
      trace: 
```

##### CaNDMAEnterMed: ( active: 4x ) accumulator

```Gen
CaNDMAEnterMed: ( active: 4x )
  type: accumulator
  contained_by: POSTSYNAPSE-BEH

  in_context: bAp_ctx
    hypothesis: NOT (Ca2+ full) AND (Na emptiness)
      action: [Ca2+ increase]
      trace: 
```

#### NOT bAp_ctx

##### CaNDMAEnterLow: ( active: 12x ) accumulator

```Gen
CaNDMAEnterLow: ( active: 12x )
  type: accumulator
  contained_by: POSTSYNAPSE-BEH

  in_context: NOT bAP_ctx
    hypothesis: NOT (Ca2+ full) AND (Na mediumness)
      action: [Ca2+ increase]
      trace: 
```

##### CaNDMAEnterMedNotBap: ( active: 4x ) accumulator

```Gen
CaNDMAEnterMedNotBap: ( active: 4x )
  type: accumulator
  contained_by: POSTSYNAPSE-BEH

  in_context: NOT bAP_ctx
    hypothesis: NOT (Ca2+ full) AND (Na fullness)
      action: [Ca2+ increase]
      trace: 
```

##### CaClearance: ( active: 24x ) accumulator

```Gen
CaClearance: ( active: 24x ) # Low
  type: accumulator
  contained_by: POSTSYNAPSE-BEH

  in_context: NOT bAP_ctx
    hypothesis: NOT (Ca2+ empty)
      action: [Ca2+ decrease]
      trace: None
```

##### VPostMax: ( active: 4x ) accumulator
```Gen
VPostMax: ( active: 4x )
  type: accumulator
  contained_by: POSTSYNAPSE-BEH

  in_context: NOT bAP_ctx
    hypothesis: ( NA fullness )
      action: [VPost increase]
      trace: None
```

##### VPostMed: ( active: 8x ) accumulator
```Gen
VPostMed: ( active: 8x )
  type: accumulator
  contained_by: POSTSYNAPSE-BEH

  in_context: NOT bAP_ctx
    hypothesis: ( NA mediumness )
      action: [VPost increase]
      trace: None
```

##### VPostMin: ( active: 16x ) accumulator
```Gen
VPostMin: ( active: 16x )
  type: accumulator
  contained_by: POSTSYNAPSE-BEH

  in_context: NOT bAP_ctx
    hypothesis: ( NA emptiness )
      action: [VPost increase]
      trace: None
```

Il VPost clearance lo facciamo qui nel container dove creaiamo anche i VPost, perche' altrimenti, se lo facessimo in DB, perderemmo l'aspetto temporale della contribuzione dei singoli POST.
##### VPostClearance: ( active: 18x ) accumulator
```Gen
VPostClearance: ( active: 18x )
  type: accumulator
  contained_by: POSTSYNAPSE-BEH

  in_context: NOT bAP_ctx
    hypothesis: NOT ( VPost empty )
      action: [VPost decrease]
      trace: None
```

Il NA clearance lo mettiamo qui come sniplet, perche' gli AMPA creano, e questi pompano fuori. Qui non e' un problema di perdere l'integrazione temporale, perche' gli AMPA sono tutti uguali nel loro behavior. Abbiamo messo gli AMPA come container perche' cosi' possiamo modularne la numerosita'.

##### NaClearanceHigh: ( active: 4x ) accumulator
```Gen
NaClearanceHigh: ( active: 4x )
  type: accumulator
  contained_by: POST-NA-CLEAR-BHE

  in_context: NOT bAP_ctx ??any??
    hypothesis: ( Na mediumness ) OR ( Na fullness )
      action: [Na decrease]
      trace: None
```

##### NaClearanceLow: ( active: 16x ) accumulator
```Gen
NaClearanceLow: ( active: 16x )
  type: accumulator
  contained_by: POST-NA-CLEAR-BHE

  in_context: NOT bAP_ctx ??any??
    hypothesis: NOT (Na empty)
      action: [Na decrease]
      trace: None
```

### TUN-POST-AMPA: Container
```Gen
TUN-POST-AMPA
  type: container
  activity_scope: !DAY
  
  tub_modulation: # in TUN agiamo su POS/ACT
   - posMod ( fullness: None, active: BEH-POST-IC/fullness, empty: 0x)  # riferimento a possible di BEH-PRE
   - actMod ( fullness: None, active: BEH-POST-IC/active, empty: BEH-POST-IC/emptiness)  # riferimento a active di BEH-PRE

  context_intricated:
  - TunPossible ( contained_by: DAY-N )

  tub_local:

  tub_intricated:
```
#### TunPossible_ctx

##### CheckTunPostAmpa: ( active: 60x ) contextor
```Gen
  CheckTunPostAmpa: ( active: 60x )
  type: contextor
  contained_by: TUN-POST-AMPA

  in_context: TunPossible_ctx
    condition:   tbd1
    out_context: TryTunUpPostAmpa_ctx

    condition:   tbd2
    out_context: TryTunDownPostAmpa_ctx
```

##### PossibleUpPostAmpaTun: ( active: 10x ) accumulator
```Gen
PossibleUpPostAmpaTun: ( active: 10x )
  type: accumulator
  contained_by: TUN-POST-AMPA

  in_context: TryTunUpPostAmpa_ctx
    hypothesis:  
      action: 
      trace: 
```

##### PossibleDownPostAmpaTun: ( active: 10x ) accumulator
```Gen
PossibleDownPostAmpaTun: ( active: 10x )
  type: accumulator
  contained_by: TUN-POST-AMPA

  in_context: TryTunDownPostAmpa_ctx
    hypothesis:  
      action: 
      trace: 
```

## POST-AMPA: Comprehension
```Gen
POST-AMPA
  type: comprehension

  instantiate_container:
      POST-AMPA-BHE []
  
```

### POST-AMPA: Container
```Gen
POST-AMPA-BHE
  type: container

  activity_scope: !DAY

  tub_intricated:
    - NT ( contained_by: ASTROCYTE/SYNAPSE )

  context_intricated:
    - Na ( contained_by: POSTSYNAPSE )
```

#### NOT bAP_ctx

##### NaAMPAEnterMax: ( active: 2x ) accumulator
```Gen
NaAMPAEnterMax: ( active: 2x )
  type: accumulator
  contained_by: POST-AMPA-BHE

  in_context: NOT bAP_ctx
    hypothesis: (NT fullness)
      action: [Na increase]
      trace: 
```

##### NaAMPAEnterMed: ( active: 4x ) accumulator
```Gen
NaAMPAEnterMed: ( active: 4x )
  type: accumulator
  contained_by: POST-AMPA-BHE

  in_context: NOT bAP_ctx
    hypothesis: (NT mediumness)
      action: [Na increase]
      trace: 
```