Lab notes: happy holidays from the Guardian Science team!

Before you settle down to festive fun and family fights, let's get the last of this year's science in your eyes! First up is a rather intriguing discovery that pregnancy appears to trigger long-term changes in brain structure. Scientists suggest that the transformations in the volume of grey matter in certain regions could boost a mother's ability to care for her newborn baby. Researchers have also identified three genes which could explain why some people are obese and healthy while others develop diabetes and heart disease as a result of their weight. It's not a reason to overdo the mince pies, but it opens up the possibility of personalised BMIs and targeted treatments in the future. And if all that just sounds too batty well, a group of scientists from Tel Aviv University have gone a bit further into that territory. Their recent study used machine learning algorithms to decode the squeaks that bats make. The scientists found that they could work out who was arguing with whom, what the squabble was about and could even predict the outcome of a disagreement - all from the bats' calls. And finally, some rather heartwarming news. After scouring the genomes of 27 patients with debilitating movement disorders which had left doctors baffled, doctors have discovered a new genetic disorder. Treatment is now possible for these children - and some have now improved so much they can walk again unaided.