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I've come across several studies in which scientists were investigating various questions related to neural activity by focusing on neuronal cell bodies using Calcium imaging. As this article suggests for example, cytosolic Ca concentration in the soma will significantly increase if the neuron fires. I understand the process behind this. But I'd like to find out if this somatic Ca increase has significant downstream effects inside the soma.

Could anyone shed some light on such known processes/pathways?

I've thought of one possibility based on an article that showed Calcium would upregulate mitochondrial enzymes, such as PDH and OGDC, responsible for TCA reactions. Considering that there's a coupling (source) between cytosolic and mitochondrial Ca concentrations, this could lead to a very quick increase in metabolic activity that covers up for the ATP loss related to neuron firing. However, I'm a bit skeptical about this idea. I'd think that the lack of ATP and low NADH/NAD ratio should speed up the TCA enough already and Ca might be more critical somewhere else instead.

Haliaetus
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    Welcome to Biology.SE! We encourage you to do some research on your own and then, informed by what you have learned, ask any questions you still have (ideally with references to reliable sources). For example, one of the top hits from searching with your title seems very relevant ...——— Please also take the [tour] and then go through the help pages starting with [Ask] questions effectively on this site and edit your question accordingly. Thanks! – tyersome Dec 12 '19 at 21:03
  • The attached article happens to be the exact same article that led me ask this question above. It clearly states that we can observe a Calcium increase in the soma related to action potential, but doesn't seem to discuss at all what the function of this Ca increase is. And that's what I'm asking here. I've done my research before asking. Of course, I could spend a few more days going through articles (that are often behind paywalls) and would eventually find the answer (if there is). But having to do this is exactly what I wanted to avoid by asking a clear question in a specialized community. – Haliaetus Dec 12 '19 at 22:08
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    I think it's a good question (+1). It could be improved by a citation (e.g., to the one tyersome suggested and that you found), and also by better clarity of what exactly you are asking (I think your comment helps but comments are ephemeral). The biggest issue that you can improve is the ambiguity of the question "why": several times you ask why but why is often misinterpreted. It seems you are not interested in how the calcium gets into the cell but rather what the purpose of calcium influx is near the soma rather than at an axon terminal. If true, can you edit to make this clear? – Bryan Krause Dec 12 '19 at 22:40
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    (these edits will help you get an answer that's actually what you want, otherwise someone could come and write an excellent answer about voltage gated calcium channels and then they will find they wasted their time if this wasn't what you wanted) – Bryan Krause Dec 12 '19 at 22:41
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    Fair point. Thank you for your well-thought comments. I edited my question accordingly. I hope now it aligns up with the standards and readers can interpret what I'm after exactly. – Haliaetus Dec 13 '19 at 00:00
  • Thanks for the edits! I've already upvoted so can't do it again, but I do hope you get a good answer. I have some ideas myself, at least one of which is mentioned here (it was in the 'related questions' on the right): https://biology.stackexchange.com/questions/36646/doubling-the-concentration-of-extracellular-calcium-hyperpolarizes-a-neuron-why?rq=1 but it will take me some time to collect references that talk about other purposes. Calcium is quite a diverse messenger so it's likely an answer will only point you in a couple directions for future research rather than give a definitive answer. – Bryan Krause Dec 13 '19 at 01:20
  • I see. Appreciate the upvote. It makes things even more interesting, if there really is not a definitive answer to this question. I'll jump back into the literature then and do some exploring. I'll start by reading into the idea brought up in that question you pointed out. Thank you for all your help. I'll keep an eye out on this thread so maybe we can discuss the findings. – Haliaetus Dec 13 '19 at 15:01
  • After doing some further research, my conclusion is that intracellular Ca levels play a role in regulating synaptic vesicle exocytosis, LTP, redox signaling, and the krebs cycle. The latter effect seems to be the most relevant one in neuronal cell bodies. – Haliaetus Jan 14 '20 at 19:54

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