Something important happens when we sleep, as you know based on how poorly you function when you do not sleep well. All animals sleep. We are using our ability to look into living zebrafish to ask how the connections in the brain change as animals sleep.
Imaging of neurons in the live fish over time allows us to observe how their structure changes during the day and night. Here the dendrites of a neuron are extending and retracting as it searches for inputs from other cells.
The synapses, where nerve cells connect with one another, can be imaged in live fish to see how they change day during day and night. The green spots are the synapses, which are marked by a synaptic protein with a green fluorescent tag. The arrows point to processes from the neuron that are attempting to form synapses, but have not.