Brain activity during nest construction
To implicate regions of the brain in nest construction behaviours, Zach Hall looked for correlations between levels of neuronal activity in different brain regions and the performance of nest building behaviours in male and female zebra finches. He measured regional neuronal activity by quantifying the number of cells expressing FOS, a protein expressed in neurons following periods of high activation (see diagram below).
Above: Left = brain cells expressing FOS. Right = Zebra Finches nest construction sequence