The Journal of Mathematical Neuroscience (JMN) levies an article processing charge of £833/$1300/€1000 for each manuscript accepted after peer review.
However, if your institution is a BioMed Central member (http://www.biomedcentral.com/inst/) then this cost will already be covered in full or in part. Moreover, authors from the following developing countries do not have to pay open access fees: http://www.biomedcentral.com/info/authors/oawaiverfund/
More good news is that for accepted papers in 2011 we are further aiming to offer fee waivers to those who do not qualify via the above schemes.