Impact of in vivo optogenetic stimulation/inhibition of PVN AT1aR neurons on anxiety-like behavior in the EPM. a, b, Open arm time (a) and total distance traveled (b) of mice that were delivered either AAV-eYFP, AAV-ChR2-eYFP, or AAV-SwiChRca bilaterally into the PVN. Blue-light stimulation parameters for the AAV-ChR2-eYFP and the AAV-eYFP mice were as follows: 20 ms pulses, 15 Hz, 5 s on followed by 5 s off. For the AAV-SwiChR2 mice, the stimulation parameters were 500 ms pulses at 0.033 Hz. The stimulation/inhibition protocols continued for the entirety of the 5 min test. Error bars indicate SEM. *p < 0.05.