Dissection of Top-down Cortical Circuits Underlying Auditory Oddball Response, a Biomarker for Schizophrenia
2020 Award: $40,000
Hallucination, or “hearing voices” is one of the most prevalent symptoms of schizophrenia. In this project we will study how internally generated signals in the brains affect sensory processing. Findings in the simple mouse brains provide a first step toward the understanding of circuit mechanisms underlying broad perceptual symptoms in schizophrenic patients.
Need/Problem: Schizophrenia is a severe mental disorder that affects 1 in 100 individuals. Schizophrenic patients suffer from symptoms such as hallucinations (hearing voices), delusions, and disordered thinking.
Grant Summary: We will study how hallucination, or hearing internally generated sounds, occurs by investigating information processing in the neural circuits within the auditory cortex
Goals and Projected Outcomes: Insights into the interplay between sensory inputs and internally generated signals within the brain will help us understand how this balance is disturbed in schizophrenic patients. This knowledge will lead to the identification of potential therapeutic targets in future.

Hiroyuki Kato, PhD
Grant Details: Auditory hallucination, or “hearing voices,” is one of the most prevalent symptoms of schizophrenia. Hallucinations arise from the erroneous attribution of internally generated sounds to external sources. For proper auditory perception, a delicate balance must be maintained between two information streams onto the auditory cortex: “bottom-up” inputs which convey external sound information from the ears and “top-down” inputs which convey internally generated signals from higher-order brain regions. Here, we will investigate the neural circuits underlying the interplay between top-down and bottom-up signals in the auditory cortex, using mouse as a model system. Using optogenetic tools to monitor and manipulate activity from specific neural populations, we will dissect the neural circuits underlying top-down modulation of sound processing in healthy brains. This will form a basis for our future study in which we aim to examine neural circuit dysfunctions in mouse models for schizophrenia. Findings in the simple mouse auditory cortex should provide a first step toward the understanding of circuit mechanisms underlying broad perceptual symptoms in schizophrenic patients and ultimately lead to the identification of potential therapeutic targets in human clinical research.