Identify Elements of the VTA Projecting RPE Circuit Neurons inMouse Mus musculus Prefrontal Cortex

Abstract

The Reward Prediction Error (RPE) model was presented decades ago but still has elements adding to the theory as
the mystery of neuron signaling pathways unravels. Following the projections of the dopaminergic neurons, the RPE
circuit originates from the ventral tegmental area (VTA), goes to the nucleus accumbens (NAc) reaches a higherorder processing center, which is the prefrontal cortex (PFC). Furthermore, downstream GABAergic neurons will be
activated according to the “error,” which indicates the value difference between the anticipated and actual rewards. This
study aims to investigate the intermediate steps of the circuit, if any, and the role these intermediate neurons played in
stimulating the GABAergic neurons after the sensory inputs are integrated and processed at the PFC. Numerous studies
have investigated the function and mechanism of the VTA-NAc-PFC connections, whereas this experiment focuses on
the second half of the circuit. At least one, and possibly many, PFC residing, VTA projecting neurons with long axons
can be identified.