For field recordings, glass pipettes (1 ΩM) were placed in the lateral amygdala, and a bipolar stimulating electrode was positioned within the external capsule dorsal to the LA. Field potentials were recorded using an Axopatch 1D amplifier. Test stimuli were delivered at a frequency of 0.05 Hz, and LFS stimuli were delivered at 10 Hz for 10 min (LFS2), based on previous studies showing that this protocol induces endocannabinoid-mediated LTD in the cortex35 and in the nucleus accumbens.36 The amplitude of field excitatory postsynaptic potentials (fEPSPs) was calculated as a percent change from baseline.
