Metabotropic glutamate and GABA receptors modulate cellular excitability and glutamatergic transmission in chicken cochlear nucleus angularis neurons.

Metabotropic glutamate and GABA receptors modulate cellular excitability and glutamatergic transmission in chicken cochlear nucleus angularis neurons. Hear Res. 2017 Jan 16;: Authors: Shi W, Lu Y Abstract Neurons in the avian cochlear nucleus angularis (NA) receive glutamatergic input from the auditory nerve, and GABAergic input from the superior olivary nucleus. Physiologically heterogeneous, NA neurons perform multiple functions including encoding sound intensity information. Using in vitro whole-cell patch recordings from acute brain slices and immunohistochemistry staining, we investigated neuromodulation mediated by metabotropic glutamate and GABA receptors (mGluRs and GABABRs) in NA neurons. Based on their intrinsic firing patterns in response to somatic current injections, NA neurons were classified into one-spike (onset), damped, and tonic cells. Pharmacological activation of group II mGluRs, group III mGluRs, and GABABRs, by their respective agonists, suppressed the cellular excitability of non-onset firing NA neurons. Each of these agonists inhibited the glutamatergic transmission in NA neurons, in a cell type-independent manner. The frequency but not the amplitude of spontaneous release of glutamate was reduced by each of these agonists, suggesting that the modulation of the glutamatergic transmission was via presynaptic actions. Interestingly, activation of group I mGluRs increased cellular excitability and suppressed glu...
Source: Hearing Research - Category: Audiology Authors: Tags: Hear Res Source Type: research