What’s new in neuroscience? A physical scientist asked me this question at a holiday party last week. I’d already been thinking about the highs and lows (but mainly highs) of what I’ve seen in 2006, so I told him about my favorite group of papers to come out in the last few months.

The genes that make us human are expressed in the brain and may be involved in brain development. This is the basic gist of several recent papers that sit on the fence between evolutionary genetics and neuroscience. Pollard et al. (my favorite of the bunch) report that among all genes, the non-coding gene HAR1F has had the most accelerated changes in the human relative to other species. HAR1F is expressed in Cajal-Retzius cells, which are important in cortical development, and is developmentally regulated. Since the cortex is specifically enlarged in humans relative to other species, these data may suggest that HAR1F is important in the evolutionary expansion of the human brain.

Popesco et al. looked for genes with the biggest copy-number expansion in humans relative to other species. They report that humans have more copies of the MGC8902 gene than other species. Humans have approximately 50 copies, whereas chimps and macaques have 10 and 4 copies, respectively. MGC8902 encodes repeats of a protein domain called DUF1220, whose function is unknown. DUF1220 domains are only found in primates. In humans, DUF1220 is found in neurons in the hippocampus, cortex and cerebellum.

Finally, Prabhakar et al. report that non-coding genes with the most human-specific substitutions are disproportionately involved in neural cell adhesion.

Best wishes for a New Year filled with great neuroscience.