Longitudinal calcium imaging of BNST neurons in mice during optogenetic manipulation of paraventricular thalamus axon terminals.

Here, we present a protocol to study neural circuits between the paraventricular thalamus (PVA) and the bed nucleus of the stria terminalis (BNST) in mice by combining calcium imaging with optogenetic stimulation of axon terminals. We describe steps for delivering GCaMP6f and ChrimsonR viruses and implanting the gradient-index (GRIN) lens for use with an Inscopix microscope. We then detail procedures for single-neuron tracking over an extended period through longitudinal recording and data smoothing and processing to enhance analysis.