Mouse age for neuropathic pain induction

What is the best age of mouse to induce neuropathic pain, specially SNI? Anyone has compared the age of mice? Any difference between 7-10 weeks old compared with older (15-20 weeks?)
@achamess @tberta @jmogil @Theodore.price

There’s very little difference between a 7-10 week old and a 15-20 week old mouse. I’d be hugely surprised if anyone ever saw any difference, especially using the extremely robust SNI. We compared 8-week-old to 12-MONTH old mice, and found no difference in SNI mechanical allodynia two weeks after surgery (Muralidharan et al., Pain Rep. 5:e824, 2020).

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Hi @jmogil. Thanks. In terms of pain hypersensitivity, I agree that it is difficult to see differences since SNI is extremely robust. What we are seeing is a huge difference in the immune response when comparing young mice (7-12 weeks) with adult mice (~ 20 weeks or older).

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How very interesting!

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Very interesting. Yeah I would not have thought there were would be much biological difference between mice that close in age. Keep us posted @thicunha

We don’t know yet if these differences are intrinsically related to age or if SPF animals start to maturate better their immune system in a conventional facility. We usually receive SPF animals at 6 weeks old and start SNI with 7-9 weeks old. So, our older mice (over 14 weeks) are in a conventional experimental facility. So, there is a bias on this point and it isn’t easy to compare.

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A related question. How long does the effect of SNI last? @jmogil nice study!

I’m not sure what you mean by “effect”. The allodynia over the lifespan is in Figure 2.

Sorry. I wrote too quickly. Didn’t mean to phrase as a question. I meant to say your study reports on the duration of SNI’s behavioral effects, as opposed to any differences in age of onset, which was Thiago questions.

Anyway, important study and interesting findings. Thanks for doing it!

Gotcha. Thanks for saying!