To date, it has yet to be investigated whether a similar modulation is evident in the human reaching-related areas. To fill this gap, we asked participants to reach towards either a small or a large object while kinematic and electroencephalographic signals were recorded. Behavioral results showed that the precision requirements were taken into account and the kinematics of reaching was modulated
depending on the object size. Similarly, reaching-related neural activity at the level of the posterior parietal and premotor cortices was modulated by the level of accuracy determined by object size. We therefore conclude that object size is engaged in the neural computations for reach planning and execution, AZD1152-HQPA datasheet Y-27632 chemical structure consistent with the results from physiological studies in non-human primates. “
“Electrophysiological studies have shown that mesostriatal dopamine (DA) neurons increase
activity in response to unpredicted rewards. With respect to other functions of the mesostriatal dopaminergic system, dopamine’s actions show prominent laterality effects. Whether changes in DA transmission elicited by rewards also are lateralized, however, has not been investigated. Using [11C]raclopride-PET to assess the striatal DA response to unpredictable monetary rewards, we hypothesized that such rewards would induce an asymmetric reduction in [11C]raclopride binding in the ventral striatum, reflecting lateralization of endogenous dopamine release. In 24 healthy volunteers, differences in the regional D2/3 receptor binding potential (ΔBP) Urease between an unpredictable reward condition and a sensorimotor control condition were measured using the bolus-plus-constant-infusion [11C]raclopride method. During the reward condition subjects randomly received monetary awards while performing a ‘slot-machine’ task. The ΔBP between conditions was assessed in striatal regions-of-interest and
compared between left and right sides. We found a significant condition × lateralization interaction in the ventral striatum. A significant reduction in binding potential (BPND) in the reward condition vs. the control condition was found only in the right ventral striatum, and the ΔBP was greater in the right than the left ventral striatum. Unexpectedly, these laterality effects appeared to be partly accounted for by gender differences, as our data showed a significant bilateral BPND reduction in women while in men the reduction reached significance only in the right ventral striatum. These data suggest that DA release in response to unpredictable reward is lateralized in the human ventral striatum, particularly in males. “
“A role for arginine vasopressin in the circadian regulation of voluntary locomotor behavior (wheel running activity) was investigated in the golden hamster, Mesocricetus auratus.