Contribution of NMDA and AMPA receptors to temporal patterning of auditory responses in the inferior colliculus.

Title

Contribution of NMDA and AMPA receptors to temporal patterning of auditory responses in the inferior colliculus.

Creator

Sanchez Jason Tait; Gans Donald; Wenstrup Jeffrey J

Publisher

The Journal of neuroscience : the official journal of the Society for Neuroscience

Date

2007
2007-02

Description

Although NMDA receptors (NMDARs) are associated with synaptic plasticity, they form an essential part of responses to sensory stimuli. We compared contributions of glutamatergic NMDARs and AMPA receptors (AMPARs) to auditory responses in the inferior colliculus (IC) of awake, adult mustached bats. We examined the magnitude and temporal pattern of responses to tonal signals in single units before, during, and after local micro-iontophoretic application of selective antagonists to AMPARs [NBQX (1,2,3,4-tetrahydro-6-nitro-2,3-dioxo-benzo[f]quinoxaline-7-sulfonamide)] and NMDARs [CPP ((+/-)3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid)]. Combined blockade of AMPARs and NMDARs eliminated excitatory responses in nearly all neurons, whereas separate blockade of each receptor was quantitatively similar, causing substantial (\textgreater 50%) spike reductions in approximately 75% of units. The major result was that effects of receptor blockade were most closely related to the first-spike latency of a unit. Thus, AMPAR blockade substantially reduced spikes in all short-latency units (\textless 12 ms) but never in long-latency units (\textgreater or = 12 ms). NMDAR blockade had variable effects on short-latency units but reduced spikes substantially for all long-latency units. There were no distinct contributions of AMPARs and NMDARs to early and late elements of responses. Thus, AMPAR blockade reduced early (onset) spikes somewhat more effectively than NMDAR blockade in short-latency units, but NMDAR blockade reduced onset spikes more effectively in long-latency units. AMPAR and NMDAR blockade were equally effective in reducing later elements of sustained responses in short-latency units, whereas NMDAR blockade was much more effective in long-latency units. These results indicate that NMDARs play multiple roles for signal processing in adult IC neurons.

Subject

Animals; Chiroptera/*physiology; Neurons/physiology; Action Potentials/drug effects; Excitatory Amino Acid Antagonists/pharmacology; Quinoxalines/pharmacology; Inferior Colliculi/cytology/drug effects/*physiology; Piperazines/pharmacology; *Acoustic Stimulation; Reaction Time/drug effects/*physiology; N-Methyl-D-Aspartate/*physiology; Receptors; AMPA/*physiology

Rights

Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).

Pages

1954–1963

Issue

8

Volume

27

Citation

Sanchez Jason Tait; Gans Donald; Wenstrup Jeffrey J, “Contribution of NMDA and AMPA receptors to temporal patterning of auditory responses in the inferior colliculus.,” NEOMED Bibliography Database, accessed April 23, 2021, https://neomed.omeka.net/items/show/5001.

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