How doo our brains work while we are consciously thinking, watching, planning, deciding, or speaking with others?
Prolactin has a stimulatory effect on milk production in mammary glands in mammals, but it also plays diverse physiological roles including effects in the central nervous system. The hyperprolactinemic state during late pregnancy and lactation is believed to affect the maternal brain by suppressing anxiety and stimulating maternal behavior. Growth hormone also affects brain functions such as memory and emotion, as well as stimulating longitudinal body growth during puberty.
The largest source of these hormones in circulation is the anterior pituitary gland, although much less is produced in other organs, including the brain. Similarly, the receptors for these hormones are expressed in a number of organs, which suggests the diverse biological effects of these hormones. Our research is focused on the mechanisms underlying the regulation of expression of growth hormones, prolactin, and their receptors in the central nervous system and the pituitary gland. An experimental study on the mechanisms for emotional responses is also underway.
Regulatory mechanisms of expression of growth hormones, prolactin, and their receptors in the central nervous system
Development of growth hormone–and prolactin-secreting cells in the anterior pituitary gland
Experimental studies aimed at elucidating the mechanisms underlying emotional expression in humans and model animals
The goal of our research is to understand the neural mechanisms underlying psychological phenomena such as attention, memory, prediction, learning, decision-making, and emotion. Experiments in our laboratory focus on the brains of awake, behaving monkeys as models for similar systems in the human brain. In particular, we are investigating the roles of monoamine systems, such as dopamine and serotonin, in cognitive, emotional, and motivational functions.
Using electrophysiological and pharmacological techniques, we examine the signals conveyed by monoamine neurons while monkeys perform behavioral tasks, and how the signals and released monoamines act on targeted brain areas to allow the animal to successfully perform the tasks. These studies will provide more mechanistic accounts of cognitive and emotional disorders.
Roles of monoamine systems in cognitive, emotional, and motivational functions
How do our brains work while we are consciously thinking, watching, planning, deciding, or speaking with others? We are studying brain functions and their mechanisms of motivation, reward expectancy, sensory perception, visual recognition, decision-making, learning, and social interaction by recording neuronal activities in animal models and analyzing information-processing mechanisms using neural or statistical models.
Brain mechanisms of information processing regarding motivation and reward expectancy
Reinforcement learning and decision-making mechanisms in the brain
Mechanism of visual recognition in the presence of visual noise
Brain mechanisms of emotional and social interaction
Time perception in decision-making
Relationship between reward-seeking and bodily awareness