Disconnection of the hippocampal–prefrontal cortical circuits impairs spatial working memory performance in rats

AbstractAlterations of resting-state EEG microstates have been associated with various neurological disorders and behavioral states. Interestingly, age-related differences in EEG microstate organization have also been reported, and it has been suggested that resting-state EEG activity may predict cognitive capacities in healthy individuals across the lifespan. In this exploratory study, we performed a microstate analysis of resting-state brain activity and tested allocentric spatial working memory performance in healthy adult individuals: twenty 25–30-year-olds and twenty-five 64–75-year-olds. We found a lower spatial working memory performance in older adults, as well as age-related differences in the five EEG microstate maps A, B, C, C′ and D, but especially in microstate maps C and C′. These two maps have been linked to neuronal activity in the frontal and parietal brain regions which are associated with working memory and attention, cognitive functions that have been shown to be sensitive to aging. Older adults exhibited lower global explained variance and occurrence of maps C and C′. Moreover, although there was a higher probability to transition from any map towards maps C, C′ and D in young and older adults, this probability was lower in older adults. Finally, although age-related differences in resting-state EEG microstates paralleled differences in allocentric spatial working memory performance, we found no evidence that any individual or combination of resting-state EEG microstate parameter(s) could reliably predict individual spatial working memory performance. Whether the temporal dynamics of EEG microstates may be used to assess healthy cognitive aging from resting-state brain activity requires further investigation.

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P2-603: MEAN ARTERIAL BLOOD PRESSURE (MABP) IS ASSOCIATED WITH SPATIAL WORKING MEMORY PERFORMANCE VIA AN EFFECT UPON FORNIX MICROSTRUCTURE IN OLDER ADULTS WITH AGE-ASSOCIATED MEMORY IMPAIRMENT (AAMI)

Alzheimer s & Dementia ◽

10.1016/j.jalz.2019.06.3013 ◽

2019 ◽

Vol 15 ◽

pp. P855-P856

Author(s):

Jeffery Michael Reddan ◽

David White ◽

Ajay S. Kurani ◽

Andrew Pipingas ◽

Helen Macpherson ◽

...

Keyword(s):

Blood Pressure ◽

Older Adults ◽

Working Memory ◽

Arterial Blood Pressure ◽

Mean Arterial Blood Pressure ◽

Memory Impairment ◽

Spatial Working Memory ◽

Memory Performance ◽

Arterial Blood

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Cholinergic enhancement improves working memory performance in young and older humans while influencing different prefrontal cortical regions

NeuroImage ◽

10.1016/s1053-8119(00)91378-8 ◽

2000 ◽

Vol 11 (5) ◽

pp. S447

Author(s):

Emiliano Ricciardi ◽

Pietro Pietrini ◽

Ulderico Freo ◽

Maura L. Furey

Keyword(s):

Working Memory ◽

Memory Performance ◽

Prefrontal Cortical ◽

Cortical Regions

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Age-Related Differences in Resting-State EEG and Allocentric Spatial Working Memory Performance

Frontiers in Aging Neuroscience ◽

10.3389/fnagi.2021.704362 ◽

2021 ◽

Vol 13 ◽

Author(s):

Adeline Jabès ◽

Giuliana Klencklen ◽

Paolo Ruggeri ◽

Jean-Philippe Antonietti ◽

Pamela Banta Lavenex ◽

...

Keyword(s):

Older Adults ◽

Working Memory ◽

Resting State ◽

Spatial Working Memory ◽

Brain Activity ◽

Memory Performance ◽

Group Differences ◽

Age Group ◽

Eeg Activity ◽

Recording Conditions

During normal aging resting-state brain activity changes and working memory performance declines as compared to young adulthood. Interestingly, previous studies reported that different electroencephalographic (EEG) measures of resting-state brain activity may correlate with working memory performance at different ages. Here, we recorded resting-state EEG activity and tested allocentric spatial working memory in healthy young (20–30 years) and older (65–75 years) adults. We adapted standard EEG methods to record brain activity in mobile participants in a non-shielded environment, in both eyes closed and eyes open conditions. Our study revealed some age-group differences in resting-state brain activity that were consistent with previous results obtained in different recording conditions. We confirmed that age-group differences in resting-state EEG activity depend on the recording conditions and the specific parameters considered. Nevertheless, lower theta-band and alpha-band frequencies and absolute powers, and higher beta-band and gamma-band relative powers were overall observed in healthy older adults, as compared to healthy young adults. In addition, using principal component and regression analyses, we found that the first extracted EEG component, which represented mainly theta, alpha and beta powers, correlated with spatial working memory performance in older adults, but not in young adults. These findings are consistent with the theory that the neurobiological bases of working memory performance may differ between young and older adults. However, individual measures of resting-state EEG activity could not be used as reliable biomarkers to predict individual allocentric spatial working memory performance in young or older adults.

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Negative Effects of Embodiment in a Visuo-Spatial Working Memory Task in Children, Young Adults, and Older Adults

Frontiers in Psychology ◽

10.3389/fpsyg.2021.688174 ◽

2021 ◽

Vol 12 ◽

Author(s):

Gianluca Amico ◽

Sabine Schaefer

Keyword(s):

Older Adults ◽

Working Memory ◽

Young Adults ◽

Spatial Information ◽

Spatial Working Memory ◽

Cognitive Task ◽

Memory Performance ◽

Age Groups ◽

Memory Task ◽

Negative Effects

Studies examining the effect of embodied cognition have shown that linking one’s body movements to a cognitive task can enhance performance. The current study investigated whether concurrent walking while encoding or recalling spatial information improves working memory performance, and whether 10-year-old children, young adults, or older adults (Mage = 72 years) are affected differently by embodiment. The goal of the Spatial Memory Task was to encode and recall sequences of increasing length by reproducing positions of target fields in the correct order. The nine targets were positioned in a random configuration on a large square carpet (2.5 m × 2.5 m). During encoding and recall, participants either did not move, or they walked into the target fields. In a within-subjects design, all possible combinations of encoding and recall conditions were tested in counterbalanced order. Contrary to our predictions, moving particularly impaired encoding, but also recall. These negative effects were present in all age groups, but older adults’ memory was hampered even more strongly by walking during encoding and recall. Our results indicate that embodiment may not help people to memorize spatial information, but can create a dual-task situation instead.

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Glutamate Carboxypeptidase II in Aging Rat Prefrontal Cortex Impairs Working Memory Performance

Frontiers in Aging Neuroscience ◽

10.3389/fnagi.2021.760270 ◽

2021 ◽

Vol 13 ◽

Author(s):

Dibyadeep Datta ◽

Shannon N. Leslie ◽

Elizabeth Woo ◽

Nishita Amancharla ◽

Ayah Elmansy ◽

...

Keyword(s):

Working Memory ◽

Memory Performance ◽

Cognitive Disorders ◽

Glutamate Carboxypeptidase Ii ◽

Prefrontal Cortical ◽

Aging Rat ◽

Medial Pfc ◽

Improved Performance ◽

Glutamate Carboxypeptidase ◽

Pentanedioic Acid

Glutamate carboxypeptidase II (GCPII) expression in brain is increased by inflammation, and reduces NAAG (N-acetyl aspartyl glutamate) stimulation of mGluR3 signaling. Genetic insults in this signaling cascade are increasingly linked to cognitive disorders in humans, where increased GCPII and or decreased NAAG-mGluR3 are associated with impaired prefrontal cortical (PFC) activation and cognitive impairment. As aging is associated with increased inflammation and PFC cognitive deficits, the current study examined GCPII and mGluR3 expression in the aging rat medial PFC, and tested whether GCPII inhibition with 2-(3-mercaptopropyl) pentanedioic acid (2-MPPA) would improve working memory performance. We found that GCPII protein was expressed on astrocytes and some microglia as expected from previous studies, but was also prominently expressed on neurons, and showed increased levels with advancing age. Systemic administration of the GCPII inhibitor, 2-MPPA, improved working memory performance in young and aged rats, and also improved performance after local infusion into the medial PFC. As GCPII inhibitors are well-tolerated, they may provide an important new direction for treatment of cognitive disorders associated with aging and/or inflammation.

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