Life inside the womb isn’t as blissfully peaceful as you might think. Babies respond to noises from the outside world many months before they are born. Our hearing begins to develop when the cochlea – a bony structure shaped like a snail’s shell – forms in the inner ear. At just over ten weeks the inside of the cochlea (circular cavity, left) is lined with unspecialised cells (stained blue) that will become sensory hair cells. The bundle of nerve cells (blue nuclei, surrounded by green and red stained proteins) will mature to convey messages to the brain by around 18 weeks. Inherited conditions and pregnancy complications – like the mother catching rubella – can stop these cells developing normally, meaning around 1 in 1000 UK babies are born deaf. Understanding inner ear development might help mitigate risks in pregnancy so fewer babies are affected, or improve the effectiveness of remedial treatments like cochlear implants.
BPoD stands for Biomedical Picture of the Day. Managed by the MRC Laboratory of Medical Sciences until Jul 2023, it is now run independently by a dedicated team of scientists and writers. The website aims to engage everyone, young and old, in the wonders of biology, and its influence on medicine. The ever-growing archive of more than 4000 research images documents over a decade of progress. Explore the collection and see what you discover. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.
BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.