I honestly never heard of this publisher but as far as I can see “IMR Press” is a legit and genuine publisher (https://www.imrpress.com ). This is based on the following facts:
-The have currently seven of their journal titles indexed in Scopus (just check here https://www.scopus.com/sources.uri?zone=TopNavBar&origin=searchbasic )
-They are member of DOAJ (https://doaj.org )
-A number of these titles are indexed in Clarivate’s SCIE and/or PubMed
These are strong indications that this is a publisher that fulfills quite a number of quality requirements when it comes to scientific publishing.
The journal “Journal of Integrative Neuroscience” is indexed in Scopus, Clarivate’s SCIE, PubMed (and even better in Medline) etc. So, this all looks fine although, personally, I find the APC of 2200 USD quite high.
But the answer to your question is that this publisher is legit.
Thank you for providing a detailed description and answers on the IMR press. Yes, I completely agree with your above-said links, as I, too, have gone through them. However, I had a doubt earlier, but now I am clear about it. Yes, the APC is way too high.