Electrical stimulation in the bed nucleus of the stria terminalis in a
rat model of anxiety
Kelly Luyck1, Bart Nuttin1,2, Laura Luyten3.
1
Laboratory of Experimental Neurosurgery and -anatomy, Department of Neurosciences,
KU Leuven, Herestraat 49, bus 1036, 3000 Leuven, Belgium
2 Neurosurgery, UZ Leuven, Herestraat 49 bus 7003, 3000 Leuven, Belgium
3 Centre for the Psychology of Learning and Experimental Psychopathology, Department of
Psychology, KU Leuven, Tiensestraat 102 bus 3712, 3000 Leuven, Belgium
With a life-time prevalence of 16 %, anxiety disorders are among the most common psychiatric
disorders. Despite their high economical and personal burden, they remain poorly understood and
current treatment options are often not adequate. Electrical brain stimulation may be a last-resort
option for these severely affected patients. Over the years, the bed nucleus of the stria terminalis
(BST) has emerged as a promising new target for treating anxiety disorders. In patients suffering from
severe, treatment-refractory obsessive-compulsive disorder (OCD), high-frequency stimulation (HFS)
in the BST area has clear anxiolytic effects. In addition, we showed that the BST is hypermetabolic in
anxious rats and that BST lesions decrease the expression of anxious behavior, as measured by the
startle response and amount of freezing. Since lesions and HFS are known to exert similar effects, we
hypothesized that HFS of the BST can reduce the expression of anxiety.
In this study, rats were bilaterally implanted with monopolar electrodes in the BST and assigned to a
stimulation (STIM, n = 10) or sham (CTRL, n = 8) group. All animals were subjected to a conditioning
paradigm, which results in expression of anxiety on the final test day. At this stage, rats in the STIM
group received HFS, whereas CTRL rats received no stimulation. Stimulation parameters were fixed at
100 Hz, 40 µs and 300 µA.
Our study revealed no significant effect of HFS on startle or freezing measurements. Despite the
success of HFS in the clinic, determining the optimal stimulation parameters is known to be a
cumbersome process, resulting in individual sets of parameters for each patient. For this reason, our
results do not necessarily exclude an anxiolytic effect of HFS in the BST, but indicate that further
research is necessary to determine the optimal method of stimulation.