Science In Action

Pain, particularly chronic pain, is hard to research. New therapeutics are hard to screen for. Patients are not all the same. Sergui Pascu and colleagues at Stanford university have been growing brain samples from stem cells. Then they began connecting different samples, specialised to represent different brain regions. This week they announce their most complex “assembloid” yet, one that even reacts to hot chilli, passing a signal from the sensory neurons through to the thinking bits. The hope is that it can provide insights on how pain, and potential painkillers, work.Human brains are notoriously large, particularly infants. Whilst for primates the human pelvis is quite narrow, to allow us to walk and run on two legs. This notoriously makes childbirth, well, not as straightforward as most other species. This evolutionary “obstetric dilemma” has been debated for decades. Marianne Brasil, of Western Washington University, and colleagues, have published this week a huge study of contemporary human genes and an