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BACKGROUND Stimulation of alpha-2 adrenoceptors in the monkey or rat prefrontal cortex (PFC) has been known to improve spatial working memory (SWM) and stimulation of alpha-1 adrenoceptors in the rat PFC has been reported to impair SWM. The present study attempted to replicate in monkey the rat experiments on alpha-1 adrenoceptor stimulation. METHODS The(More)
The effects of systemically administered or iontophoretically applied clonidine (alpha-2 adrenergic agonist) and iontophoretically applied yohimbine (alpha-2 adrenergic antagonist) were examined on prefrontal cortical (PFC) neurons related to spatial working memory (SWM). Systemically administered clonidine (0.04 mg/kg) enhanced SWM-related PFC neuronal(More)
The effects of clonidine (a selective agonist for alpha-2 receptor) and B-HT920 (an agonist for both alpha-2 and D2 receptors) were examined iontophoretically on neurons in the prefrontal cortex of three monkeys performing a visual discrimination task with GO and NO-GO responses. A total of 212 task-related neurons were sampled, of which 120 neurons were(More)
BACKGROUND Many neuropsychiatric disorders are associated with high levels of noradrenergic turnover, and most antipsychotic medications have alpha-1 adrenoceptor blocking properties, yet little is known about alpha-1 influences on higher cortical function. METHODS The alpha-1 adrenergic agonist, phenylephrine, was infused into the prefrontal cortex (PFC)(More)
To explore the role of the ventral prefrontal cortex (PFv) in conditional visuomotor learning, we infused locally bicuculline, a GABAergic antagonist, into the PFv of two monkeys, well trained on a two-problem visuomotor task. The task required the monkeys to execute one of two motor actions (moving a handle to the left or to the right) in response to one(More)
A previous study showed that intra-CAl infusion of the beta-adrenergic antagonist DL-propranolol interfered with consolidation of memory for contextual fear conditioning (J.-Z. Ji, X.-M. Wang, & B.-M. Li, 2003). The present study investigated the effect of similarly administered DL-propranolol on consolidation of spatial memory for the water maze.(More)
In order to examine whether the basal ganglia are involved in arbitrary visuomotor association, we recorded neuronal activity in the internal segment of the globus pallidus (GPi) of monkeys during a conditional visuomotor learning task. Two monkeys were presented a cueing visual stimulus, and following a delay period required to push, pull or turn a(More)
A multibarreled glass-coated tungsten microelectrode suitable for single-unit recording and iontophoresis in chronically behaving animals is described. The microelectrode was stiff enough to pass through the dura matter of behaving monkeys, and can be applied as a microiontophoretic electrode. The electrode is easy to build and usable in stabilized(More)
To examine functional roles of the medial prefrontal cortex (mPFC) in visuomotor association learning, neuronal activity in the mPFC of a behaving monkey was recorded during this learning. The monkey was presented a cueing visual stimulus, and required to push, pull or turn a manipulator according to the cue following a delay period. Under the control(More)