Plates-Formes de Recherche en Neurosciences

logo amu logo cnrs

Plates-formes PFRN

Accueil > Bibliographie > Dopamine transporter is essential for the maintenance of spontaneous (...)

Dopamine transporter is essential for the maintenance (...)

J Neurochem. 2006 Apr ;97(1):190-200
Dopamine transporter is essential for the maintenance of spontaneous activity of auditory nerve neurones and their responsiveness to sound stimulation.
Ruel J, Wang J, Dememes D, Gobaille S, Puel JL, Rebillard G.

Dopamine, a neurotransmitter released by the lateral olivocochlear efferents, has been shown tonically to inhibit the spontaneous and sound-evoked activity of auditory nerve fibres. This permanent inhibition probably requires the presence of an efficient transporter to remove dopamine from the synaptic cleft. Here, we report that the dopamine transporter is located in the lateral efferent fibres both below the inner hair cells and in the inner spiral bundle. Perilymphatic perfusion of the dopamine transporter inhibitors nomifensine and N-[1-(2-benzo[b]thiophenyl)cyclohexyl]piperidine into the cochlea reduced the spontaneous neural noise and the sound-evoked compound action potential of the auditory nerve in a dose-dependent manner, leading to both neural responses being completely abolished. We observed no significant change in cochlear responses generated by sensory hair cells (cochlear microphonic, summating potential, distortion products otoacoustic emissions) or in the endocochlear potential reflecting the functional state of the stria vascularis. This is consistent with a selective action of dopamine transporter inhibitors on auditory nerve activity. Capillary electrophoresis with laser-induced fluorescence (EC-LIF) measurements showed that nomifensine-induced inhibition of auditory nerve responses was due to increased extracellular dopamine levels in the cochlea. Altogether, these results show that the dopamine transporter is essential for maintaining the spontaneous activity of auditory nerve neurones and their responsiveness to sound stimulation.

PubMed

    Ils nous font confiance

  • logo amu
  • logo cnrs
  • logo inserm
  • logo AP-HM
  • logo F�d�ration pour la Recherche sur le Cerveau
  • logo Fondation pour la Recherche Medical en France
  • logo IBiSA
  • logo Europe programme FEDER
  • logo Agence Nationale de la Recherche
  • logo Plateforme Technologique Aix-Marseille
  • logo Vect-Horus
  • logo Neuron Experts