# soma.md Qui comprendiamo: - SOMA: il soma - VGSC-SOMA-H: Na ion channels. Open only when VDB high - VGSC-SOMA-M: Na ion channels. Open only when VDB medium - VGSC-SOMA-L: Na ion channels. Open only when VDB low ## SOMA: Container --- **Simplified behaviors**: — ms: - Resting at -70 mV: Leak channels + pumps (keep at resting) -- ? - VDB Depolarization : ~1-2 ms: Na⁺ enters (some VGSCs open) - Opened VGSC remain closed for a refractory period Spike if depolarized above threshold: to -50 mV -- Here the threshold is based only on the integration of Na+ -- The threshold is tuned during the spiketrain. Low threshold at rest, to increase sensitivity, threshold increase during spike to increase discrimination -- increase SpikeTrainTraces (fast at spike) -- increase Ca2+ traces - Repolarization to -70 mV: ~1-2 ms: K⁺ exits (VG K⁺ channels open) ← NOT pumps! -- fast pump which decreases Na+, we do not model K+ - After-hyperpolarization: ~5-20 ms: K⁺ channels still open -- must figure out how to deal with deoplarization -- decrease SpikeTraintraces slow, only if away from spiketrain this is empty — seconds: - Return to exact -70 mV: ~100-1000 ms: Na⁺/K⁺ pumps restore gradients -- slow pump - Ca2+ accumulation: SpikeTrainTraces -- ? — mins: - VGSC modulation --- **Tubs:** - **VDB**: dendrites deliver current - **Na**: are a proxy for the Coulombs of charge building up on the somatic membrane. They are used to check threshold, but also to mimic Na+ and K+ pumping - **AP**: - **bAP**: - **Ca2+**: Medium term traces to guide tuning and Night development. It is a local trace, ATP is a global (Astrocyte) - **SpikeTrainTraces**: sono le tracce che consentono al neurone di far partire il Tuning neuronale, quando e' lontano da uno spike-train, ovvero e' in riposo. --- ```Gen container: SOMA expansion: - VGSC-SOMA-H ( fullness: 50x, active: 20x, emptiness: 10x ) # modulated_by: VGSC-SOMA-H-TUN # possible/actual - VGSC-SOMA-M ( fullness: 50x, active: 20x, emptiness: 10x ) # modulated_by: VGSC-SOMA-M-TUN # possible/actual - VGSC-SOMA-L ( fullness: 50x, active: 20x, emptiness: 10x ) # modulated_by: VGSC-SOMA-L-TUN # possible/actual tub_local: - VDB - Na - Ca2+ tub_intricated: - SpikeTrainTraces ( contained_in: DAY-N ) ``` ### ms: SOMA #### CheckVDB: Context As dendrites deliver current (VDB​), the soma acts like a capacitor. It "stores" this charge in the form of membrane potential. This contextualizes VGSC-SOMA to open ion channels that let Na+ ions in. This only applies if not AP, or in other words, SOMA is not in refractory period. ```Gen context: CheckVDB contained_by: SOMA in_context: Fixed rf: ( active: 60x ) condition: (VDB fullness ) AND NOT AP out_context: VDBMax condition: ( VDB mediumness ) AND NOT AP out_context: VDBMedium condition: ( VDB emptiness ) AND NOT AP out_context: VDBLow ``` #### CheckSomaSpike: Context The initiation and duration of a spike ```Gen context: CheckSomaSpike contained_by: SOMA in_context: Fixed rf: ( active: 60x ) condition: ( Na fullness OR APRefractory ) out_context: AP out_context: bAP ``` #### SomaSpike: Episode ```Gen episode: SomaSpike contained_by: SOMA in_context: AP rf: ( active: 8x ) hypothesis: action: trace: ``` #### ClearNa: Episode ```Gen episode: ClearNa contained_by: SOMA in_context: Fixed rf: ( active: 8x ) hypothesis: action: trace: ``` ### sec: SOMA ### min: SOMA #### VGSC-SOMA-TUN: Tuner ```Gen tuner: VGSC-SOMA-TUN contained_by: SOMA tunes: SOMA/expansion/VGSC-SOMA context_intricated: - TunPossible ( contained_by: DAY-N ) tub_local: tub_intricated: ``` ##### Context ```Gen context: Check contained_by: VGSC-SOMA-TUN in_context: TunPossible rf: ( active: 60x ) condition: out_context: TunSomaVcgg ``` ##### Episode ```Gen episode: ? contained_by: TUN-PRE-VGCC in_context: TunSomaVcgg rf: ( active: x ) hypothesis: action: trace: ``` ## VGSC-SOMA-H: Container Voltage Gated Sodium Channel ```Gen container: VGSC-SOMA-H ``` ### sec: VGSC-SOMA-H #### Episode1 ```Gen episode: ?? contained_by: VGSC-H-SOMA in_context: xxx rf: ( active: 1x ) hypothesis: action: trace: None ``` ## VGSC-SOMA-M: Container Voltage Gated Sodium Channel ```Gen container: VGSC-SOMA-M ``` ### sec: VGSC-SOMA-M #### Episode2 ```Gen episode: ?? contained_by: VGSC-M-SOMA in_context: xxx rf: ( active: 1x ) hypothesis: action: trace: None ``` ## VGSC-SOMA-L: Container Voltage Gated Sodium Channel ```Gen container: VGSC-SOMA-M ``` ### sec: VGSC-SOMA-L #### Episode3 ```Gen episode: ?? contained_by: VGSC-L-SOMA in_context: xxx rf: ( active: 1x ) hypothesis: action: trace: None ```