The benefits of sleep seem obvious. And yet scientists have long debated precisely how it improves brain performance at the cellular level. One camp argues that sleep reduces the unimportant connections between neurons, preventing brain overload. Another camp maintains that sleep consolidates memories from the previous day.
A group of researchers recently tried to settle this debate by studying the larvae of a common see-through aquarium pet, the zebrafish. Like humans, zebrafish are active during the day and sleep at night. Unlike humans, zebrafish larvae are transparent, which allowed researchers to watch their brains as they slept. The researchers, led by Lior Appelbaum and Philippe Mourrain of Stanford University, tagged the larvae neurons with a dye so that active neuron connections, or synapses, appeared green, whereas
