Acute unilateral DBS of the basolateral amygdala does not affect motricity, anxiety-like behavior, or fear memory consolidation in rats.

Deep brain stimulation (DBS) is an alternative to ablative functional neurosurgeries. The basolateral amygdala (BLA) is a potential DBS target for treating psychiatric disorders. However, understanding the associated behavioral and cognitive effects is necessary for safety and tolerability concerns. Therefore, we investigated potential acute effects of unilateral BLA DBS. Adult male Wistar rats were implanted with monopolar electrodes in the right BLA. In Experiment 1, different groups of animals were stimulated for 10 min with either high-frequency (HFS, 130 Hz) or low-frequency (LFS, 20 Hz) stimulation using different stimulation intensities (0 [Control], 10, 50, or 100 µA). Immediately after stimulation, animals were tested in the elevated plus-maze (EPM) and subsequently in the open field test (OFT). In Experiment 2, two groups of animals were subjected to a fear-conditioning protocol and stimulated with HFS or LFS (50 µA) immediately after conditioning. Animals were then tested for short- (2 h) and long-term (24 h) fear memory consolidation. BLA DBS showed no significant effects on: (i) anxiety-like behavior expression for HFS (p = 0.46) or LFS (p = 0.37); (ii) locomotor activity (HFS, p = 0.12; LFS, p = 0.60), in terms of distance traveled in the OFT, or (iii) fear memory consolidation (HFS, p = 0.31; LFS, p = 0.68). Under the stimulation parameters and experimental conditions tested, acute unilateral BLA DBS did not significantly affect spontaneous locomotor activity, anxiety-like behavior, or fear memory consolidation in rats. These results provide information relevant to the tolerability and safety of amygdala DBS.