  Neuroscientists today can measure activity from more neurons than ever
before, and are facing the challenge of connecting these brain-wide neural
recordings to computation and behavior. Here, we first describe emerging tools
and technologies being used to probe large-scale brain activity and new
approaches to characterize behavior in the context of such measurements. We
next highlight insights obtained from large-scale neural recordings in diverse
model systems, and argue that some of these pose a challenge to traditional
theoretical frameworks. Finally, we elaborate on existing modelling frameworks
to interpret these data, and argue that interpreting brain-wide neural
recordings calls for new theoretical approaches that may depend on the desired
level of understanding at stake. These advances in both neural recordings and
theory development will pave the way for critical advances in our understanding
of the brain.
