Kei Oyama

Longitudinal assessment of DREADD expression and efficacy in the monkey brain

This study longitudinally assesses DREADD expression and efficacy in macaque monkeys using PET imaging and functional studies, showing peak expression at 60 days and sustained effects for two years.

Distinct roles of monkey OFC-subcortical pathways in adaptive behavior

This study identifies distinct OFC-subcortical pathways in macaques that support experience-based and inference-based value updating during adaptive decision-making.

Multimodal imaging for validation and optimization of ion channel-based chemogenetics in nonhuman primates

The paper validates and optimizes the PSAM/PSEM chemogenetic system in nonhuman primates using multimodal imaging techniques to determine optimal agonist, dose, and timing for neuronal manipulation.

Chemogenetic disconnection between the orbitofrontal cortex and the rostromedial caudate nucleus disrupts motivational control of goal-directed action

This study disrupts the connection between the orbitofrontal cortex and rostromedial caudate nucleus in macaques using chemogenetics, showing it impairs reward-based motivational control of goal-directed actions.

Chronic behavioral manipulation via orally delivered chemogenetic actuator in macaques

This study evaluates orally delivered DCZ for chronic chemogenetic control of neuronal activity in macaques, showing prolonged effects and working memory impairments without desensitization.

Single caudate neurons encode temporally discounted value for formulating motivation for action

The paper shows that neurons in the primate caudate head encode temporally discounted value for delayed rewards, essential for motivation.

Chemogenetic dissection of the primate prefronto-subcortical pathways for working memory and decision-making

This study uses chemogenetic methods to selectively silence prefronto-subcortical pathways in monkeys, revealing distinct roles in working memory and decision-making.

Deschloroclozapine, a potent and selective chemogenetic actuator enables rapid neuronal and behavioral modulations in mice and monkeys

This paper introduces deschloroclozapine (DCZ), a potent and selective DREADD agonist that rapidly modulates neuronal activity and behavior in mice and monkeys.

Signaling incentive and drive in the primate ventral pallidum for motivational control of goal-directed action

This study investigates how the ventral pallidum and rostromedial caudate encode reward size and satiation level in macaques performing a lever-release task, showing VP has stronger coding and more severe inactivation effects on goal-directed behavior.