TY - JOUR T1 - Group II Metabotropic Glutamate Receptors Modulate Sound Evoked and Spontaneous Activity in the Mouse Inferior Colliculus JF - eneuro JO - eNeuro DO - 10.1523/ENEURO.0328-20.2020 VL - 8 IS - 1 SP - ENEURO.0328-20.2020 AU - Inga Kristaponyte AU - Nichole L. Beebe AU - Jesse W. Young AU - Sharad J. Shanbhag AU - Brett R. Schofield AU - Alexander V. Galazyuk Y1 - 2021/01/01 UR - http://www.eneuro.org/content/8/1/ENEURO.0328-20.2020.abstract N2 - Little is known about the functions of Group II metabotropic glutamate receptors (mGluRs2/3) in the inferior colliculus (IC), a midbrain structure that is a major integration region of the central auditory system. We investigated how these receptors modulate sound-evoked and spontaneous firing in the mouse IC in vivo. We first performed immunostaining and tested hearing thresholds to validate vesicular GABA transporter (VGAT)-ChR2 transgenic mice on a mixed CBA/CaJ x C57BL/6J genetic background. Transgenic animals allowed for optogenetic cell-type identification. Extracellular single neuron recordings were obtained before and after pharmacological mGluR2/3 activation. We observed increased sound-evoked firing, as assessed by the rate-level functions (RLFs), in a subset of both GABAergic and non-GABAergic IC neurons following mGluR2/3 pharmacological activation. These neurons also displayed elevated spontaneous excitability and were distributed throughout the IC area tested, suggesting a widespread mGluR2/3 distribution in the mouse IC. ER -