title: Long-term potentiation and depression after unilateral labyrinthectomy in the medial vestibular nucleus of rats.
abstract: We previously demonstrated in rat brainstem slices that high-frequency stimulation (HFS) of the vestibular afferents induces long-term potentiation (LTP) in the ventral part (Vp) of the medial vestibular nucleus (MVN) and long-term depression (LTD) in the dorsal part (Dp). Both LTP and LTD depend on N-methyl-D-aspartate receptor activation, which increases synaptic efficacy; however, in the Dp, LTP reverses to LTD because of the activation of gamma-aminobutyric acid-ergic neurons. Here we show that the probability of inducing long-term effects in the MVN of rat brainstem slices is altered after unilateral labyrinthectomy (UL). In fact, LTP occurs less frequently in the ventral contra-lesional side compared with sham-operated rats. In the dorsal ipsi-lesional side, LTD is reduced and LTP enhanced, while the opposite occurs in the dorsal contra-lesional side. These changes in synaptic plasticity may be useful for re-balancing the tonic discharge of the MVN of the two sides during vestibular compensation, and for enhancing the dynamic responses of the deafferented MVN neurons in the long term.
authors.affiliation: Department of Internal Medicine, Section of Human Physiology, University of Perugia, Perugia, Italy. isfisuma@unipg.it
authors.forename: Vito Enrico
authors.initials: VE
authors.lastname: Pettorossi
authors.forename: Mayank
authors.initials: M
authors.lastname: Dutia
authors.forename: Adele
authors.initials: A
authors.lastname: Frondaroli
authors.forename: Cristina
authors.initials: C
authors.lastname: Dieni
authors.forename: Silvarosa
authors.initials: S
authors.lastname: Grassi
mesh_terms: D000222:Adaptation, Physiological; D000704:Analysis of Variance; D000818:Animals; D001933:Brain Stem / Q000502:physiology*; D046508:Culture Techniques; D004195:Disease Models, Animal; D007758:Ear, Inner / Q000601:surgery*; D004594:Electrophysiology; D016057:Evoked Potentials, Auditory, Brain Stem; D005260:Female; D017774:Long-Term Potentiation; D008297:Male; D009473:Neuronal Plasticity; D013506:Otologic Surgical Procedures / Q000379:methods; D011336:Probability; D051381:Rats; D017208:Rats, Wistar; D012680:Sensitivity and Specificity; D014726:Vestibular Nuclei / Q000502:physiology*