Altered neuronal intrinsic properties and reduced synaptic transmission of the rat's medial geniculate body in salicylate-induced tinnitus.
Sodium salicylate (NaSal), an aspirin metabolite, can cause tinnitus in animals and human subjects. To explore neural mechanisms underlying salicylate-induced tinnitus, we examined effects of NaSal on neural activities of the medial geniculate body (MGB), an auditory thalamic nucleus that provides the primary and immediate inputs to the auditory cortex, by using the whole-cell patch-clamp recording technique in MGB slices. Rats treated with NaSal (350 mg/kg) showed tinnitus-like behavior as revealed by the gap prepulse inhibition of acoustic startle (GPIAS) paradigm. NaSal (1.4 mM) decreased the membrane input resistance, hyperpolarized the resting membrane potential, suppressed current-evoked firing, changed the action potential, and depressed rebound depolarization in MGB neurons. NaSal also reduced the excitatory and inhibitory postsynaptic response in the MGB evoked by stimulating the brachium of the inferior colliculus. Our results demonstrate that NaSal alters neuronal intrinsic properties and reduces the synaptic transmission of the MGB, which may cause abnormal thalamic outputs to the auditory cortex and contribute to NaSal-induced tinnitus.
CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, University of Science and Technology of China, Hefei, China.
Yan-Yan
YY
Su
Bin
B
Luo
Yan
Y
Jin
Shu-Hui
SH
Wu
Edward
E
Lobarinas
Richard J
RJ
Salvi
Lin
L
Chen
D000161:Acoustic Stimulation; D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000633:toxicity; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects; D005260:Female; D005829:Geniculate Bodies / Q000187:drug effects* / Q000503:physiopathology; D007245:Inferior Colliculi / Q000187:drug effects / Q000503:physiopathology; D053444:Inhibitory Postsynaptic Potentials / Q000187:drug effects; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D009433:Neural Inhibition / Q000187:drug effects; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D018408:Patch-Clamp Techniques; D051381:Rats; D017208:Rats, Wistar; D011963:Receptors, GABA-A / Q000502:physiology; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology; D013216:Reflex, Startle / Q000187:drug effects; D012980:Sodium Salicylate / Q000633:toxicity*; D009435:Synaptic Transmission / Q000187:drug effects*; D014012:Tinnitus / Q000139:chemically induced / Q000503:physiopathology*
D000894:Anti-Inflammatory Agents, Non-Steroidal; D011963:Receptors, GABA-A; D016194:Receptors, N-Methyl-D-Aspartate; D012980:Sodium Salicylate