BDNF signaling in the rat cerebello‐vestibular pathway during vestibular compensation: BDNF signaling in vestibular compensation

• Published in: The FEBS journal 2015-09, Vol.282 (18), p.3579-3591
• Main Authors: Zhou, Liuqing, Zhou, Wen, Zhang, Sulin, Liu, Bo, Liang, Pei, Zhou, Yan, Zhou, Tao, Zhang, Kun, Leng, Yangming, Kong, Weijia
• Format: Article
• Language: English
• Subjects: Animals; Brain-Derived Neurotrophic Factor - genetics; Brain-Derived Neurotrophic Factor - physiology; brain‐derived neurotrophic factor; Cells; central nervous system; cerebello‐vestibular pathway; Cerebellum - physiology; gamma-Aminobutyric Acid - metabolism; Immunohistochemistry; Isoenzymes - genetics; Isoenzymes - metabolism; K Cl- Cotransporters; K+‐Cl− cotransporter isoform 2; Male; Models, Neurological; Neural Pathways; Neurology; Neuronal Plasticity; Polymerase chain reaction; Purkinje Cells - metabolism; quantitative polymerase chain reaction; Rats; Rats, Sprague-Dawley; receptor protein-tyrosine kinase; Receptor, trkB - genetics; Receptor, trkB - metabolism; RNA, Messenger - genetics; RNA, Messenger - metabolism; Signal Transduction; Symporters - genetics; Symporters - metabolism; Synaptic Transmission; TrkB isoforms; Up-Regulation; vestibular compensation; Vestibular Nuclei - physiology; Western blotting
• ISSN: 1742-464X; 1742-4658
• DOI: 10.1111/febs.13360

Vestibular compensation, which is the behavioral recovery from lesions to the peripheral vestibular system, is attributed to plasticity of the central vestibular system. It has been reported that brain‐derived neurotrophic factor (BDNF) is expressed and released in an activity‐dependent manner. Upon binding to the tyrosine receptor kinase B (TrkB), BDNF can acutely modulate synaptic transmission and plasticity in the central nervous system. To assess the possible contribution of BDNF to this recovery process, we studied the expression of BDNF, TrkB.FL, TrkB.T1 and KCC2 (K⁺‐Cl⁻ cotransporter isoform 2) in the bilateral medial vestibular nucleus (MVN) and the flocculus of rats at 4 h, 8 h, 1, 3 and 7 days following unilateral labyrinthectomy (UL) using immunohistochemistry, quantitative real‐time PCR and western blotting. Our results have shown that, compared with the sham controls and the contra‐lesional side, (a) the expression of BDNF and TrkB.FL increased at 4 h in the ipsi‐lesional flocculus after UL; (b) the expression of TrkB.T1 decreased at 4 h and KCC2 decreased at 8 h and 1 day in the ipsi‐lesional flocculus after UL; and (c) BDNF and TrkB.FL expression was enhanced and KCC2 expression was reduced in the ipsi‐lesional MVN at 8 h after UL. Our data supported the hypothesis that BDNF upregulation may reduce the inhibitory effects of the flocculus and commissural inhibition system by regulating inhibitory GABAergic synaptic transmission in floccular Purkinje cells and Purkinje cell terminals in the MVN. Additionally, KCC2 may be a switch in this process.