Phytohormone abscisic acid elicits positive effects on harmaline‐induced cognitive and motor disturbances in a rat model of essential tremor

OBJECTIVE: Essential tremor (ET) as a neurological disorder is accompanied by cognitive and motor disturbances. Despite the high incidence of ET, the drug treatment of ET remains unsatisfactory. Recently, abscisic acid (ABA) has been reported to have positive neurophysiological effects in mammals. Here, the effects of ABA on harmaline‐induced motor and cognitive impairments were investigated in rats. METHODS: Male Wistar rats weighing 120–140 g were divided into control, harmaline (30 mg/kg, ip), ABA vehicle (DMSO+normal saline), and ABA (10 μg/rat, icv, 30 min before harmaline injection) groups. Exploratory, balance and motor performance, anxiety, and cognitive function were assessed using footprint, open field, wire grip, rotarod, and shuttle box tests. RESULTS: The results indicated that ABA (10 μg/rat) can improve harmaline‐induced tremor in rats. The administration of ABA significantly increased time spent on wire grip and rotarod. In addition, ABA had a promising effect against the cognitive impairments induced by harmaline. CONCLUSION: Taken together, ABA has positive effects on locomotor and cognitive impairments induced by tremor. However, further studies are required to determine the exact mechanisms of ABA on the ET.