The common aquarium pet Zebrafish is the new interest for neuroscientists at Stanford University. The fish is easy to breed and is a vertebrate with a neural structure similar to that of humans. As it is transparent, it is also easy for study without dissection.
Researchers found that homoeostatic mechanisms and circadian rhythms (like sleep-wake cycles) affect the structure of brain synapses. Further neuropeptide hypocretin secreted by the thalamus was found responsible for insomnia. They studied this by using chemical dyes to mark active and inactive neural connections in sleeping fish.
Recently other scientists found that active neural connections decreased during sleep particularly in circuits moderating learning and memory. This pattern is not seen during memory consolidation.
This suggests that sleep may instead shut down unnecessary neural connections thereby erasing unnecessary memory & prepares the brain to assimilate new information.
