Development of GPCR modulation of GABAergic transmission in chicken nucleus laminaris neurons.

Title

Development of GPCR modulation of GABAergic transmission in chicken nucleus laminaris neurons.

Creator

Tang Zheng-Quan; Lu Yong

Publisher

PloS one

Date

2012
1905-07

Description

Neurons in the nucleus laminaris (NL) of birds act as coincidence detectors and encode interaural time difference to localize the sound source in the azimuth plane. GABAergic transmission in a number of CNS nuclei including the NL is subject to a dual modulation by presynaptic GABA(B) receptors (GABA(B)Rs) and metabotropic glutamate receptors (mGluRs). Here, using in vitro whole-cell patch clamp recordings from acute brain slices of the chick, we characterized the following important but unknown properties pertaining to such a dual modulation: (1) emergence of functional GABA synapses in NL neurons; (2) the temporal onset of neuromodulation mediated by GABA(B)Rs and mGluRs; and (3) the physiological conditions under which GABA(B)Rs and mGluRs are activated by endogenous transmitters. We found that (1) GABA(A)R-mediated synaptic responses were observed in about half of the neurons at embryonic day 11 (E11); (2) GABA(B)R-mediated modulation of the GABAergic transmission was detectable at E11, whereas the modulation by mGluRs did not emerge until E15; and (3) endogenous activity of GABA(B)Rs was induced by both low- (5 or 10 Hz) and high-frequency (200 Hz) stimulation of the GABAergic pathway, whereas endogenous activity of mGluRs was induced by high- (200 Hz) but not low-frequency (5 or 10 Hz) stimulation of the glutamatergic pathway. Furthermore, the endogenous activity of mGluRs was mediated by group II but not group III members. Therefore, autoreceptor-mediated modulation of GABAergic transmission emerges at the same time when the GABA synapses become functional. Heteroreceptor-mediated modulation appears at a later time and is receptor type dependent in vitro.

Subject

Animals; Patch-Clamp Techniques; *Synaptic Transmission; gamma-Aminobutyric Acid/*metabolism; Neurons/*metabolism; Brain/*cytology; Chickens/*metabolism; Synapses/metabolism; Receptors; G-Protein-Coupled/*metabolism; GABA-A/metabolism; GABA-B/metabolism; Metabotropic Glutamate/metabolism

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

e35831–e35831

Issue

4

Volume

7

Citation

Tang Zheng-Quan; Lu Yong, “Development of GPCR modulation of GABAergic transmission in chicken nucleus laminaris neurons.,” NEOMED Bibliography Database, accessed February 28, 2021, https://neomed.omeka.net/items/show/4941.

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