Neurons in Monkey Dorsal Raphe Nucleus Code Beginning and Progress of Step-by-Step Schedule, Reward Expectation, and Amount of Reward Outcome in the Reward Schedule Task

The dorsal raphe nucleus is the major source of serotonin in the brain. It is connected to brain regions related to reward processing, and the neurons show activity related to predicted reward outcome. Clinical observations also suggest that it is important in maintaining alertness and its apparent role in addiction seems to be related to reward processing. Here, we examined whether the neurons in dorsal raphe carry signals about reward outcome and task progress during multitrial schedules. We recorded from 98 single neurons in dorsal raphe of two monkeys. The monkeys perform one, two, or three visual discrimination trials (schedule), obtaining one, two, or three drops of liquid. In the valid cue condition, the length and brightness of a visual cue indicated schedule progress and reward amount, respectively. In the random cue condition, the visual cue was randomly presented with respect to schedule length and reward amount. We found information encoded about (1) schedule onset, (2) reward expectation, (3) reward outcome, and (4) reward amount in the mean firing rates. Information theoretic analysis showed that the temporal variation of the neuronal responses contained additional information related to the progress of the schedule toward the reward rather than only discriminating schedule onset or reward/no reward. When considered in light of all that is known about the raphe in anatomy, physiology, and behavior, the rich encoding about both task progress and predicted reward outcome makes the raphe a strong candidate for providing signals throughout the brain to coordinate persistent goal-seeking behavior

LDB1 (LIM domain binding 1)

Review on LDB1 (LIM domain binding 1), with data on DNA, on the protein encoded, and where the gene is implicated

報酬探索における行動成績に対する自己選択の効果

筑波大学 (University of Tsukuba)201

アルツハイマー病モデルマウスにおける障害物回避歩行時の記憶誘導性動作の障害

学位の種別: 課程博士審査委員会委員 : (主査)東京大学准教授 柳原 大, 東京大学教授 中澤 公孝, 東京大学教授 福井 尚志, 東京大学准教授 工藤 和俊, 東京大学准教授 吉岡 伸輔University of Tokyo(東京大学

Three-dimensional markerless motion capture of multiple freely behaving monkeys toward automated characterization of social behavior

Given their high sociality and close evolutionary distance to humans, monkeys are an essential animal model for unraveling the biological mechanisms underlying human social behavior and elucidating the pathogenesis of diseases exhibiting abnormal social behavior. However, behavioral analysis of naturally behaving monkeys requires manual counting of various behaviors, which has been a bottleneck due to problems in throughput and objectivity. Here, we developed a three-dimensional markerless motion capture system that used multi-view data for robust tracking of individual monkeys and accurate reconstruction of the three-dimensional poses of multiple monkeys living in groups. Validation analysis in two monkey groups revealed that the system enabled the characterization of individual social dispositions and relationships through automated detection of eight basic social events. Analyses of social looking demonstrated its potential for investigating adaptive behaviors in a social group. These results suggest that this motion capture system will greatly enhance our ability to analyze primate social behavior.journal articl

On the vibration of the Double Eccentric Guide Cam at High Speed

A modern cam mechanism requires very litt1e amplitude of the vibration in its high speed revolution. For this purpose the eccentric cam mechanism is considered to be desirable. The authors examined the vibration of the Mi1anese guide cam. Getting aconnstant displacement in this mechanism. we used a compound cam mechanism with the primary eccentricity of 8 mm and the secondary ecentricity of 2 mm. We examined the amplitude of the vibration in the region from 600 to 1800 rpm and compared the experimental restilts with the theoretical resu1ts calculated by the authorsdepartmental bulletin pape

Neurons in the monkey orbitofrontal cortex mediate reward value computation and decision-making

Choice reflects the values of available alternatives; more valuable options are chosen more often than less valuable ones. Here we studied whether neuronal responses in orbitofrontal cortex (OFC) reflect the value difference between options, and whether there is a causal link between OFC neuronal activity and choice. Using a decision-making task where two visual stimuli were presented sequentially, each signifying a value, we showed that when the second stimulus appears many neurons encode the value difference between alternatives. Later when the choice occurs, that difference signal disappears and a signal indicating the chosen value emerges. Pharmacological inactivation of OFC neurons coding for choice-related values increases the monkey’s latency to make a choice and the likelihood that it will choose the less valuable alternative, when the value difference is small. Thus, OFC neurons code for value information that could be used to directly influence choice

A GATA4-regulated tumor suppressor network represses formation of malignant human astrocytomas

GATA4 loss as a result of promoter hypermethylation or somatic mutation promotes growth and chemotherapy resistance of human astrocytomas