a1 Department of Neuroscience, Rosalind Franklin University of Medicine and Science, The Chicago Medical School, 3333 Green Bay Road, North Chicago, IL 60064, USA
Gaining insight into how the nervous system functions is a challenge for scientists, particularly because the static morphology of the brain and the cells within tell little about how they actually work. Fixed specimens can provide critical structural information, but the jump to functional neurobiology in living cells is obviated with these preparations. In order to grasp the complexity of neuronal activity, it is necessary to observe the brain in action, from the level of subcellular signaling to the whole organism. Recent advances in nonlinear microscopy have given rise to a new era for biological research. In particular, the introduction of multiphoton excitation has drastically improved the depth and speed to which we can probe brain function. In order to better appreciate recent contributions of multiphoton microscopy to our current and future understanding of biological systems, an historical awareness of past microscopy applications is useful.
(Received June 30 2008)
(Accepted July 07 2008)