Nicergoline facilitates vestibular compensation in aged male rats with unilateral labyrinthectomy

The ergoline derivatives, nicergoline (NIC) or dihydroergocristine (DHE) were administered at various doses (0.1, 0.5 and 1 mg/kg) to aged male rats subjected to labyrinth unilateral lesion (LBX). The nystagmus rate appeared to be lower in animals treated with DHE or NIC 1 mg/kg than in saline-injected rats, when observed on day 1 and 2 after operation. The number of falls in the rotorod test of LEX animals was decreased by NIC 0.5 or 1 mg/kg at all observation times. This parameter was affected by DHE only at the higher dose. These results suggest that NIC facilitates vestibular compensation of LEX rats. DHE appeared to be less potent in this respect. Since both drugs act on central dopaminergic neurotransmission, it is possible that this neurotransmission may be involved in their mechanism of action. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.