Effects of long-term exercise and low-level inhibition of GABAergic synapses on motor control and the expression of BDNF in the motor related cortex

Abstract

ObjectivesBrain-derived neurotrophic factor (BDNF) plays important roles in neuroplasticity in the brain. The objective of this study was to examine the effects of long-term exercise combined with low-level inhibition of GABAergic synapses on motor control and the expression of BDNF in the motor-related cortex.MethodsICR mice were divided into four groups based on the factors exercise and GABAA receptor inhibition. We administered the GABAA receptor antagonist bicuculline intraperitoneally (0.25 mg/kg). Mice exercised on a treadmill 5 days/week for 4 weeks. Following behavioral tests, BDNF expression in the motor cortex and cerebellar cortex was assayed using RT-PCR and ELISA.ResultsExercise increased BDNF protein in the motor cortex and improved motor coordination in the rotarod test either in the presence or absence of bicuculline. BDNF mRNA expression in the motor cortex and muscle coordination in the wire hang test decreased after administration of bicuculline, whereas bicuculline administration increased mRNA and protein expression of BDNF in the cerebellum.DiscussionThe present study revealed that long-term exercise increased BDNF expression in the motor cortex and facilitated a transfer of motor learning from aerobic exercise to postural coordination. Thus, aerobic exercise is meaningful for conditioning motor learning to rehabilitate patients with central nervous system (CNS) disorders. However, long-term inhibition of GABAA receptors decreased the expression of cortical BDNF mRNA and decreased muscle coordination, despite the increase of BDNF in the cerebellum, suggesting that we have to consider the term of the inhibition of the GABAergic receptor for future clinical application to CNS patients.