Expression of NMDA, AMPA and GABA(A) receptor subunit mRNAs in the rat auditory brainstem. II. Influence of intracochlear electrical stimulation.
We investigated the effects of intracochlear electrical stimulation (ICES) on auditory pathways of neonatal rat deafened by daily amikacin injections. Expression of mRNAs encoding ionotropic glutamate receptor subunits such as alpha-amino-3-hydroxy-5-methyl-4-isoxazole (AMPA) and N-methyl-D-aspartate (NMDA), and gamma-aminobutyric acid type A (GABA(A)) receptor subunits was assessed by in situ hybridization in the dorsal (DCN) and the ventral cochlear nucleus (VCN) and in the central nucleus of the inferior colliculus (CNIC). After 15 days of daily unilateral ICES, the expressions of NR1, NR2b and NR2c subunits of NMDA receptor, that of GluRA, B, C, D flop isoforms of AMPA receptor and that of some GABA(A) subunits (alpha1, beta1, gamma1, gamma2) were increased bilaterally in the DCN, VCN and the CNIC. These changes last over a week after stimulation for only NR1 and NR2c. These modifications might be related to long lasting synaptic plasticity of brainstem auditory pathways. As far as analogy to deaf children can be made, early electrical stimulation might be of interest to maintain neuronal networks.
Liao
W H
WH
Service d'Otorhinolaryngologie de l'hopital Lariboisière et Neurobiologie des Réseaux Sensorimoteurs, UPRESA-CNRS 7060, Faculté Lariboisière-St-Louis, Paris, France.
Van Den Abbeele
T
T
Herman
P
P
Frachet
B
B
Huy
P T
PT
Lecain
E
E
Marianowski
R
R
D000818:Animals; D001306:Auditory Pathways / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D001345:Autoradiography; D001933:Brain Stem / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D003054:Cochlear Implants; D017626:Cochlear Nucleus / Q000378:metabolism / Q000473:pathology; D003638:Deafness / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D004558:Electric Stimulation; D016057:Evoked Potentials, Auditory, Brain Stem; D017403:In Situ Hybridization; D007245:Inferior Colliculi / Q000378:metabolism / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D018091:Receptors, AMPA / Q000235:genetics / Q000378:metabolism*; D011963:Receptors, GABA-A / Q000235:genetics / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate / Q000235:genetics / Q000378:metabolism*
D012333:RNA, Messenger; D018091:Receptors, AMPA; D011963:Receptors, GABA-A; D016194:Receptors, N-Methyl-D-Aspartate