Feedback from teachers during in-service courses shows that they are fascinated by neuroscience, as they feel that it has the potential to improve their teaching practice. There were two main outcomes from a small-scale action research project with primary and secondary science advanced skills teachers (AST) in North Yorkshire. The first is that there are many myths circulating in education about the application of brain-based research to classroom practice. The second, and the focus for this two-part article, is how three dynamic brain models underpin some aspects of the way the human brain learns and provide credence for the AST's exemplary practice. This led to 15 messages and some concluding notes for teachers to improve learning in their classrooms. The first eight messages concern brain biology and are introduced here with their implications for teachers. A future article will consider working memory and learning. (Contains 2 figures.)