I'd like to understand better the effect and functional role of voltage-gated channels on dendrites.
What I believe to have understood:
It is important that a more distal post-synaptical potential (PSP) arrives at roughly the same time and with roughly the same strength at the soma than a more proximal PSP generated at the same time (to give them comparable weights and to detect that they were synchronous). Let me call this the goal of adjustment.
Achieving this goal is the main function of (properly distributed) voltage-independent channels on dendrites (→ Rall model)
The main function of voltage-gated channels on axons is unattenuated signal transport.
Voltage-gated channels on the dendrite lead to non-linearities.
The immediate physical effect of voltage-gated channels on the dendrite is hard for me to imagine and understand. But even harder to understand are the (specific) functional advantages and disadvantages of those channels.
Some possibilities come to mind:
They allow to achieve adjustment better (more precisely) or in some other way more efficiently.
They allow to achieve other goals better or more efficiently (which are only poorly achieved without them).
They allow to achieve completely new goals which are not achievable at all without them (by having some magic computational powers due to non-linearities).
They may have disadvantages (which should not exceed there advantages, otherwise they would not exist), e.g. by distorting PSPs in an unwanted way.
I know that there is a lot of literature on the topic of dendritic processing, but not so many gentle introductions. A gentle introduction - answering some of the following question - would be welcome. And of course immediate answers!
- Do voltage-gated channels on dendrites (distributed as they are) allow to achieve adjustment better or in some other way more efficiently?
- Which other goals do they allow to achieve better or more efficiently?
- Which new goals do they allow to achieve?
- Can their extra computational powers be pinned down?
- Which disadvantages do they have (possibly)?
[I believe it wouldn't make sense to split this question into five: they are too strongly related, aren't they?]