scholarly journals Cholinergic modulation of working memory activity in primate prefrontal cortex

2011 ◽  
Vol 106 (5) ◽  
pp. 2180-2188 ◽  
Author(s):  
Xin Zhou ◽  
Xue-Lian Qi ◽  
Kristy Douglas ◽  
Kathini Palaninathan ◽  
Hyun Sug Kang ◽  
...  
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Neuronal Activity ◽  
Visual Processing ◽  
Spatial Location ◽  
Visually Guided ◽  
Electrode Arrays ◽  
Dose Dependent Decrease ◽  
Higher Cognitive Functions ◽  
The Impact

The prefrontal cortex, a cortical area essential for working memory and higher cognitive functions, is modulated by a number of neurotransmitter systems, including acetylcholine; however, the impact of cholinergic transmission on prefrontal activity is not well understood. We relied on systemic administration of a muscarinic receptor antagonist, scopolamine, to investigate the role of acetylcholine on primate prefrontal neuronal activity during execution of working memory tasks and recorded neuronal activity with chronic electrode arrays and single electrodes. Our results indicated a dose-dependent decrease in behavioral performance after scopolamine administration in all the working memory tasks we tested. The effect could not be accounted for by deficits in visual processing, eye movement responses, or attention, because the animals performed a visually guided saccade task virtually error free, and errors to distracting stimuli were not increased. Performance degradation under scopolamine was accompanied by decreased firing rate of the same cortical sites during the delay period of the task and decreased selectivity for the spatial location of the stimuli. These results demonstrate that muscarinic blockade impairs performance in working memory tasks and prefrontal activity mediating working memory.

scholarly journals The role of prefrontal cortex in working memory: examining the contents of consciousness

1998 ◽  
Vol 353 (1377) ◽  
pp. 1819-1828 ◽  
Author(s):  
◽  
S. M. Courtney ◽  
L. Petit ◽  
J. V. Haxby ◽  
L. G. Ungerleider
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Visual Processing ◽  
Right Hemisphere ◽  
Functional Organization ◽  
Spatial Working Memory ◽  
Domain Specificity ◽  
Long Term Memory ◽  
Present Evidence ◽  
The Right

Working memory enables us to hold in our ‘mind's eye’ the contents of our conscious awareness, even in the absence of sensory input, by maintaining an active representation of information for a brief period of time. In this review we consider the functional organization of the prefrontal cortex and its role in this cognitive process. First, we present evidence from brain–imaging studies that prefrontal cortex shows sustained activity during the delay period of visual working memory tasks, indicating that this cortex maintains on–line representations of stimuli after they are removed from view. We then present evidence for domain specificity within frontal cortex based on the type of information, with object working memory mediated by more ventral frontal regions and spatial working memory mediated by more dorsal frontal regions. We also propose that a second dimension for domain specificity within prefrontal cortex might exist for object working memory on the basis of the type of representation, with analytic representations maintained preferentially in the left hemisphere and image–based representations maintained preferentially in the right hemisphere. Furthermore, we discuss the possibility that there are prefrontal areas brought into play during the monitoring and manipulation of information in working memory in addition to those engaged during the maintenance of this information. Finally, we consider the relationship of prefrontal areas important for working memory, both to posterior visual processing areas and to prefrontal areas associated with long–term memory.

scholarly journals Working memory gates visual input to primate prefrontal neurons

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Behrad Noudoost ◽  
Kelsey Lynne Clark ◽  
Tirin Moore
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Sensory Input ◽  
Neural Circuits ◽  
Visual Input ◽  
Visually Guided ◽  
Visual Neurons ◽  
Cortical Inputs ◽  
Behaving Monkeys ◽  
Visual Cortical

Visually guided behavior relies on the integration of sensory input and information held in working memory (WM). Yet it remains unclear how this is accomplished at the level of neural circuits. We studied the direct visual cortical inputs to neurons within a visuomotor area of prefrontal cortex in behaving monkeys. We show that the efficacy of visual input to prefrontal cortex is gated by information held in WM. Surprisingly, visual input to prefrontal neurons was found to target those with both visual and motor properties, rather than preferentially targeting other visual neurons. Furthermore, activity evoked from visual cortex was larger in magnitude, more synchronous, and more rapid, when monkeys remembered locations that matched the location of visual input. These results indicate that WM directly influences the circuitry that transforms visual input into visually guided behavior.

scholarly journals Encoding of Serial Order in Working Memory: Neuronal Activity in Motor, Premotor, and Prefrontal Cortex during a Memory Scanning Task

2018 ◽  
Vol 38 (21) ◽  
pp. 4912-4933 ◽  
Author(s):  
Adam F. Carpenter ◽  
Gabriel Baud-Bovy ◽  
Apostolos P. Georgopoulos ◽  
Giuseppe Pellizzer
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Neuronal Activity ◽  
Serial Order ◽  
Memory Scanning ◽  
Scanning Task

The impact of age on prefrontal cortex integrity during spatial working memory retrieval

2014 ◽  
Vol 59 ◽  
pp. 157-168 ◽  
Author(s):  
Max Toepper ◽  
Hans J. Markowitsch ◽  
Helge Gebhardt ◽  
Thomas Beblo ◽  
Eva Bauer ◽  
...  
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Memory Retrieval ◽  
Spatial Working Memory ◽  
The Impact

scholarly journals Working memory performance and neural activity in prefrontal cortex of peripubertal monkeys

2013 ◽  
Vol 110 (11) ◽  
pp. 2648-2660 ◽  
Author(s):  
Xin Zhou ◽  
Dantong Zhu ◽  
Xue-Lian Qi ◽  
Cynthia J. Lees ◽  
Allyson J. Bennett ◽  
...  
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Neuronal Activity ◽  
Neural Activity ◽  
Developmental Stages ◽  
Memory Performance ◽  
Large Fraction ◽  
Early Adulthood ◽  
Delayed Response ◽  
Distractor Stimulus

The dorsolateral prefrontal cortex matures late into adolescence or early adulthood. This pattern of maturation mirrors working memory abilities, which continue to improve into adulthood. However, the nature of the changes that prefrontal neuronal activity undergoes during this process is poorly understood. We investigated behavioral performance and neural activity in working memory tasks around the time of puberty, a developmental event associated with the release of sex hormones and significant neurological change. The developmental stages of male rhesus monkeys were evaluated with a series of morphometric, hormonal, and radiographic measures. Peripubertal monkeys were trained to perform an oculomotor delayed response task and a variation of this task involving a distractor stimulus. We found that the peripubertal monkeys tended to abort a relatively large fraction of trials, and these were associated with low levels of task-related neuronal activity. However, for completed trials, accuracy in the delayed saccade task was high and the appearance of a distractor stimulus did not impact performance significantly. In correct trials delay period activity was robust and was not eliminated by the presentation of a distracting stimulus, whereas in trials that resulted in errors the sustained cue-related activity was significantly weaker. Our results show that in peripubertal monkeys the prefrontal cortex is capable of generating robust persistent activity in the delay periods of working memory tasks, although in general it may be more prone to stochastic failure than in adults.

scholarly journals Prefrontal Cortex and Working Memory for Spatial Response, Spatial Location, and Visual Object Information in the Rat

1996 ◽  
Vol 6 (2) ◽  
pp. 311-318 ◽  
Author(s):  
Raymond P. Kesner ◽  
Mary E. Hunt ◽  
Joseph M. Williams ◽  
Jeffrey M. Long
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Spatial Location ◽  
Visual Object ◽  
Spatial Response

scholarly journals LOW-DIMENSIONAL STRUCTURES: SPARSE CODING FOR NEURONAL ACTIVITY

2013 ◽  
Vol 06 (01) ◽  
pp. 1350002 ◽  
Author(s):  
YUNHUA XU ◽  
WENWEN BAI ◽  
XIN TIAN
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Neuronal Activity ◽  
Sparse Coding ◽  
Neural Coding ◽  
Memory Task ◽  
Work Memory ◽  
Neuronal Ensemble ◽  
Coding Method ◽  
Low Dimensional

Neuronal ensemble activity codes working memory. In this work, we developed a neuronal ensemble sparse coding method, which can effectively reduce the dimension of the neuronal activity and express neural coding. Multichannel spike trains were recorded in rat prefrontal cortex during a work memory task in Y-maze. As discrete signals, spikes were transferred into continuous signals by estimating entropy. Then the normalized continuous signals were decomposed via non-negative sparse method. The non-negative components were extracted to reconstruct a low-dimensional ensemble, while none of the feature components were missed. The results showed that, for well-trained rats, neuronal ensemble activities in the prefrontal cortex changed dynamically during the working memory task. And the neuronal ensemble is more explicit via using non-negative sparse coding. Our results indicate that the neuronal ensemble sparse coding method can effectively reduce the dimension of neuronal activity and it is a useful tool to express neural coding.

scholarly journals Cholinergic Enhancement Eliminates Modulation of Neural Activity by Task Difficulty in the Prefrontal Cortex during Working Memory

2008 ◽  
Vol 20 (7) ◽  
pp. 1342-1353 ◽  
Author(s):  
Maura L. Furey ◽  
Emiliano Ricciardi ◽  
Mark B. Schapiro ◽  
Stanley I. Rapoport ◽  
Pietro Pietrini
Keyword(s):  
Working Memory ◽  
Blood Flow ◽  
Prefrontal Cortex ◽  
Reaction Time ◽  
Visual Processing ◽  
Task Difficulty ◽  
Brain Activity ◽  
Task Demands ◽  
Positron Emission ◽  
The Right

Previously, we demonstrated that enhancing cholinergic activity during a working memory (WM) task improves performance and reduces blood flow in the right anterior middle/superior frontal cortex, an area known to be important for WM. The purpose of this study was to evaluate the interaction between WM task demands and cholinergic enhancement on neural responses in the prefrontal cortex. Regional cerebral blood flow (rCBF) was measured using H215O and positron emission tomography, as 10 young healthy volunteers performed a parametrically varied match-to-sample WM for faces task. For each item, a picture of a face was presented, followed by a delay (1, 6, 11, or 16 sec), then by the presentation of two faces. Subjects were instructed to identify which face they previously had seen. For control items, nonsense pictures were presented in the same spatial and temporal manner. All conditions were performed during an intravenous infusion of saline and physostigmine (1 mg/hr). Subjects were blind to the substance being infused. Reaction time increased significantly with WM delay, and physostigmine decreased reaction time across delay conditions. Significant task-related rCBF increases during saline infusion were seen in superior frontal, middle frontal, and inferior frontal regions, and the response magnitudes in the regions increased systematically with task difficulty. In all of these prefrontal regions, physostigmine administration significantly reduced rCBF during task, particularly at longer task delays, so that no correlation between task delay and rCBF was observed. In the ventral visual cortex, physostigmine increased rCBF at longer task delays in medial regions, and decreased rCBF over delay conditions in lateral cortical areas. These results indicate that, during cholinergic potentiation, brain activity in prefrontal regions is not modulated by increases in WM task demands, and lends further support to the hypothesis that cholinergic modulation enhances visual processing, making the task easier to perform, and thus, compensate for the need to recruit prefrontal cortical regions as task demands increase.

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