Section through an octopus shows the mouth passing through the brain

Octopuses and other cephalopods are well-known for their exceptional intelligence and complex brains, which appear to outstrip all other invertebrates’. But, they work within one strange constraint – like all other molluscs (snails, slugs, oysters and more), the nerve ring at the centre of their nervous system encircles the oesophagus. In cephalopods, this nerve ring…

#fossilfriday: Preserved brain visible in 520 million year-old arthropod

Almost all fossils represent the hard parts of long-gone animals: teeth, shells, bones and others. But palaeontologists do occasionally find fossilised soft tissue, too. This remarkable fossil was the first to be described where the brain and parts of the nervous system are visible – astonishingly – after more than 500 million years! Fuxianhuia protensa, an ancient…

Section through lower spinal cord, labelled with fluorescent markers

Lumbar (lower) spinal cord, sectioned and labelled using fluorescent markers. The markers attach to antibodies which are introduced by the researcher and designed to bind to specific proteins. This technique is called immunofluorescence. Here, green indicates markers for sensory neurons, red shows motor neurons and blue highlights rough endoplasmic reticulum – where most protein synthesis takes…