The GPCR signalling cascade is a key pathway responsible for the signal
transduction of a multitude of physical and chemical stimuli, including
light, odorants, neurotransmitters, and hormones. Understanding the
structural and functional properties of the GPCR cascade requires direct
observation of signalling processes in high spatial and temporal
resolution with minimal perturbation to endogenous systems. Optical
microscopy and spectroscopy techniques are uniquely suited to this
purpose because they excel at multiple spatial and temporal scales and
can be used in living objects. Here, we review recent developments in
microscopy and spectroscopy technologies which enable new insights into
GPCR signalling. We focus on advanced techniques with high spatial and
temporal resolution, single-molecule methods, labelling strategies, and
approaches suitable for endogenous systems and large living objects.
This review aims to assist researchers in choosing appropriate
microscopy and spectroscopy approaches for a variety of applications in
the study of cellular signalling.