Lamotrigine increases the number of BrdU-labeled cells in the rat hippocampus

Antidepressant medication and electroconvulsive therapy stabilize mood symptoms and increase hippocampal neurogenesis. We examined whether lamotrigine, suggested to give rise to mood-stabilizing and antidepressant effects in addition to its antiepileptic properties, also increases the number of newborn cells in rat hippocampus. Rats (on day P21) received lamotrigine, valproate, or saline intraperitoneally once daily for 7 days. All animals received four intraperitoneal injections of bromodeoxyuridine (BrdU) on day P28 and were sacrificed the next day. Quantification of BrdU-labeled cells in the granule cell layer of the dentate gyrus showed an increased number of newborn cells in rats receiving lamotrigine (42.6 +/- 3.5 cells/slice) compared with valproate (31.6 +/- 2.8) and controls (32.2 +/- 3.1; P < 0.05). The increased number of BrdU-labeled cells suggests increased neurogenesis, possibly explaining the mood-stabilizing and antidepressant effects of lamotrigine. NeuroReport 22: 97-100 (C) 2011 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.