scholarly journals Ketamine-Induced Changes in the Signal and Noise of Rule Representation in Working Memory by Lateral Prefrontal Neurons

2015 ◽  
Vol 35 (33) ◽  
pp. 11612-11622 ◽  
Author(s):  
Liya Ma ◽  
Kevin Skoblenick ◽  
Jeremy K. Seamans ◽  
Stefan Everling
Keyword(s):  
Working Memory ◽  
Induced Changes ◽  
Rule Representation

scholarly journals Glucagon-like peptide-2 rescues memory impairments and neuropathological changes in a mouse model of dementia induced by the intracerebroventricular administration of streptozotocin

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sachie Sasaki-Hamada ◽  
Masaatsu Ikeda ◽  
Jun-Ichiro Oka
Keyword(s):  
Oxidative Stress ◽  
Working Memory ◽  
Memory Impairment ◽  
Spatial Working Memory ◽  
Thiobarbituric Acid ◽  
Intracerebroventricular Administration ◽  
Sporadic Alzheimer’S Disease ◽  
Memory Impairments ◽  
Glucagon Like Peptide ◽  
Induced Changes

Abstract Glucagon-like peptide 2 (GLP-2) is derived from the proglucagon gene expressed in the intestines, pancreas and brain. Our previous study showed that GLP-2 improved lipopolysaccharide-induced memory impairments. The current study was designed to further investigated the potential of GLP-2 in memory impairment induced by intracerebroventricular administration of streptozotocin (ICV-STZ) in mice, which have been used as an animal model of sporadic Alzheimer’s disease (AD). STZ was administered on alternate days (Day-1 and Day-3) in order to induce dementia in male ddY mice. ICV-STZ-treated mice were administered GLP-2 (0.6 μg/mouse, ICV) for 5 days from 14 days after the first ICV administration of STZ. In these mice, we examined spatial working memory, the biochemical parameters of oxidative stress, or neurogenesis. The GLP-2 treatment restored spatial working memory in ICV-STZ-treated mice. ICV-STZ-treated mice showed markedly increased thiobarbituric acid reactive species (TBARS) and decreased glutathione (GSH) levels, and GLP-2 significantly restored these ICV-STZ-induced changes. GLP-2 also significantly restored neurogenesis in the subgranular zone of the dentate gyrus in ICV-STZ-treated mice. We herein demonstrated that GLP-2 significantly restored ICV-STZ-induced memory impairments as well as biochemical and histopathological alterations, and accordingly, propose that the memory restorative ability of GLP-2 is due to its potential to reduce oxidative stress.

scholarly journals Dopamine Alters the Fidelity of Working Memory Representations according to Attentional Demands

2017 ◽  
Vol 29 (4) ◽  
pp. 728-738 ◽  
Author(s):  
Sean James Fallon ◽  
Nahid Zokaei ◽  
Agnes Norbury ◽  
Sanjay G. Manohar ◽  
Masud Husain
Keyword(s):  
Working Memory ◽  
Stochastic Model ◽  
Receptor Agonist ◽  
Response Selection ◽  
Recall Performance ◽  
Drug Induced ◽  
Capacity Limitations ◽  
Significant Difference ◽  
Memory Representations ◽  
Induced Changes

Capacity limitations in working memory (WM) necessitate the need to effectively control its contents. Here, we examined the effect of cabergoline, a dopamine D2 receptor agonist, on WM using a continuous report paradigm that allowed us to assess the fidelity with which items are stored. We assessed recall performance under three different gating conditions: remembering only one item, being cued to remember one target among distractors, and having to remember all items. Cabergoline had differential effects on recall performance according to whether distractors had to be ignored and whether mnemonic resources could be deployed exclusively to the target. Compared with placebo, cabergoline improved mnemonic performance when there were no distractors but significantly reduced performance when distractors were presented in a precue condition. No significant difference in performance was observed under cabergoline when all items had to be remembered. By applying a stochastic model of response selection, we established that the causes of drug-induced changes in performance were due to changes in the precision with which items were stored in WM. However, there was no change in the extent to which distractors were mistaken for targets. Thus, D2 agonism causes changes in the fidelity of mnemonic representations without altering interference between memoranda.

scholarly journals Effects of Frontoparietal Theta tACS on Verbal Working Memory: Behavioral and Neurophysiological Analysis

2021 ◽  
Author(s):  
Zhenhong Hu ◽  
Immanuel B.H. Samuel ◽  
Sreenivasan Meyyappan ◽  
Ke Bo ◽  
Chandni Rana ◽  
...  
Keyword(s):  
Working Memory ◽  
Memory Load ◽  
Working Memory Capacity ◽  
Memory Task ◽  
Verbal Working Memory ◽  
Memory Retention ◽  
Electrode Arrays ◽  
Frontoparietal Network ◽  
The Subject ◽  
Induced Changes

Left-lateralized frontoparietal theta oscillations are thought to play an important role in verbal working memory. We causally tested this idea by stimulating the frontoparietal theta network at individual theta frequencies (4 to 8 Hz) during verbal working memory and observing the subsequent behavioral and neurophysiological effects. Weak electric currents were delivered via two 4x1 HD electrode arrays centered at F3 and P3. Three stimulation configurations, including in-phase, anti-phase, or sham, were tested on three different days in a cross-over design. On each test day, the subject underwent three experimental sessions: pre-, during- and post-stimulation sessions. In all sessions, the subject performed a Sternberg verbal working memory task with three levels of memory load (load 2, 4 and 6), imposing three levels of cognitive demand. Analyzing behavioral, EEG, and pupillometry data from the post-stimulation sessions, we report three results. First, in-phase stimulation improved task performance only in subjects with higher working memory capacity (WMC) and under higher memory load (load 6). Second, in-phase stimulation enhanced frontoparietal theta synchrony during working memory retention only in subjects with higher WMC under higher memory loads (load 4 and load 6), and the enhanced frontoparietal theta synchronization is mainly driven by enhanced frontal -> parietal theta Granger causality. Third, the pupil diameter was not different irrespective of whether the preceding stimulation was in-phase, anti-phase, or sham. These findings suggest that theta tACS effects on verbal working memory were load- and subject-dependent, rooted in tACS-induced changes in frontoparietal network interactions, and not driven by changes in arousal levels.

Conceptual short-term memory (CSTM) supports core claims of Christiansen and Chater

2016 ◽  
Vol 39 ◽  
Author(s):  
Mary C. Potter
Keyword(s):  
Working Memory ◽  
Rapid Serial Visual Presentation ◽  
Language Comprehension ◽  
Short Term Memory ◽  
Visual Presentation ◽  
Long Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Use Of Knowledge

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.

The bottleneck may be the solution, not the problem

2016 ◽  
Vol 39 ◽  
Author(s):  
Arnon Lotem ◽  
Oren Kolodny ◽  
Joseph Y. Halpern ◽  
Luca Onnis ◽  
Shimon Edelman
Keyword(s):  
Working Memory ◽  
Language Acquisition ◽  
Recent Theory ◽  
Cognitive Mechanisms ◽  
Selection Pressures ◽  
Biological Trait ◽  
Memory Bottleneck

AbstractAs a highly consequential biological trait, a memory “bottleneck” cannot escape selection pressures. It must therefore co-evolve with other cognitive mechanisms rather than act as an independent constraint. Recent theory and an implemented model of language acquisition suggest that a limit on working memory may evolve to help learning. Furthermore, it need not hamper the use of language for communication.

Sign in / Sign up

Export Citation Format

Share Document