Medial geniculate body and primary auditory cortex differentially contribute to striatal sound representations

TLDR

The dorsal striatum, especially its auditory subregion, integrates convergent inputs from the medial geniculate body and primary auditory cortex, yet the distinct contributions of these pathways to striatal auditory processing remain largely unknown. The authors used chemogenetic inhibition of MGB‑to‑auditory‑striatum and ACx‑to‑auditory‑striatum projections in mice to assess their roles in an auditory frequency discrimination task. Silencing the MGB projection broadly diminished striatal sound responses, acting as a gain controller, while silencing the ACx projection selectively reduced responses at preferred frequencies, providing tuning information for striatal sound representations.

Abstract

Abstract The dorsal striatum has emerged as a key region in sensory-guided, reward-driven decision making. A posterior sub-region of the dorsal striatum, the auditory striatum, receives convergent projections from both auditory thalamus and auditory cortex. How these pathways contribute to auditory striatal activity and function remains largely unknown. Here we show that chemogenetic inhibition of the projections from either the medial geniculate body (MGB) or primary auditory cortex (ACx) to auditory striatum in mice impairs performance in an auditory frequency discrimination task. While recording striatal sound responses, we find that transiently silencing the MGB projection reduced sound responses across a wide-range of frequencies in striatal medium spiny neurons. In contrast, transiently silencing the primary ACx projection diminish sound responses preferentially at the best frequencies in striatal medium spiny neurons. Together, our findings reveal that the MGB projection mainly functions as a gain controller, whereas the primary ACx projection provides tuning information for striatal sound representations.