Fig. 3. Effects of gabapentin and pregabalin on γ-amino butyric acid (GABA) release in the locus coeruleus (LC) and spinal cord (SC). Normal (A  and C ) and spinal nerve ligated (SNL: B  and D ) rats received intravenous saline, gabapentin (GBP 10 and 50 mg/kg), or pregabalin (PGB, 30 mg/kg). Changes in GABA content in microdialysates from the LC (A  and B ) and spinal cord (C  and D ) are presented over time as percentage of baseline. N = 8–14. *P < 0.05 versus  saline.