The brain is a bit like a trifle. Only instead of having delicious layers of cream and berries, it has delicate tiers of neurons. This complexity makes it tough to recreate in a dish.
Researchers have moved one step closer to accomplishing this feat using a ‘bioprinter’ — a 3D printer for tissue. They concocted a gummy ‘bio-ink’ replete with mouse neurons and then printed 1-centimeter-tall globs that look more like gummy bears than a trifle. Over time, neurons made connections through the layers as they do in the brain.
The findings, published last month in Biomaterials, offer an exciting (albeit preliminary) alternative to neuron spheres and other attempts to culture neurons in three dimensions.
Speaking of beautiful brain layers, who hasn’t considered getting a tattoo of one of Santiago Ramón y Cajal’s sketches? Okay, maybe that’s just me. In any case, a story in last week’s Science shows how the Spanish neuroscientist’s classification of neurons, which he called “the butterflies of the soul,” remains controversial today.
The piece talks about lumpers, who focus on what different types of neurons have in common, and splitters, who focus on subtle differences. Cajal was “a pathological splitter,” according to Richard Masland, professor of ophthalmology at Harvard Medical School. Masland argues that new techniques, such as RNA sequencing, have changed the way we view neuronal diversity. I, for one, am glad that Cajal used a microscope, pen and paper.
Not to dwell on the output of 3D printers, but we thought this was worth a mention: The U.S. Food and Drug Administration has approved the first 3D-printed pill — an epilepsy drug called Spritam. The printing technique can pack a gram of drug into a porous pill that “rapidly disintegrates with a sip of liquid,” according to the drug maker, Aprecia. Spritam could serve as another option for the one in four children with autism who also have epilepsy.