Egyptian fruit bats exhibit precise 3D spatial memory that eclipses sensory information

2021 ◽  
Vol 150 (4) ◽  
pp. A140-A140
Author(s):  
Xiaoyan Yin ◽  
Cynthia Moss
Keyword(s):  
Spatial Memory ◽  
Sensory Information ◽  
Fruit Bats

scholarly journals Hippocampal CA2 ripples recruit social replay and promote social memory

2020 ◽  
Author(s):  
Oliva Azahara ◽  
Fernández-Ruiz Antonio ◽  
Leroy Felix ◽  
Siegelbaum A. Steven
Keyword(s):  
Spatial Memory ◽  
Memory Consolidation ◽  
Slow Wave Sleep ◽  
Social Memory ◽  
Declarative Memory ◽  
Critical Role ◽  
Sensory Information ◽  
General Mechanism ◽  
Recent Experience ◽  
Wide Range

The consolidation of spatial memory depends on the reactivation (‘replay’) of hippocampal place cells that were active during recent behavior. These reactivations are observed during sharp wave-ripples (SWRs), synchronous oscillatory events that occur during slow-wave sleep1–9 and whose disruption impairs spatial memory consolidation 4,6,7,9. Although the hippocampus encodes a wide range of non-spatial forms of declarative memory, it is not yet known whether SWRs are necessary for non-spatial memory. Moreover, although SWRs can arise from either the hippocampal CA38 or CA210 regions, the relative importance of these sources for memory consolidation is unknown. Here we examined the role of SWRs during the consolidation of social memory, the ability of an animal to recognize and remember a conspecific, focusing on CA2 because of its critical role in social memory11,12,13. We found that ensembles of CA2 pyramidal neurons that were active during social exploration of novel conspecifics were reactivated during SWRs. Importantly, disruption or enhancement of CA2 SWRs suppressed or prolonged social memory, respectively. Thus, SWR reactivation of hippocampal firing related to recent experience appears to be a general mechanism for binding spatial, temporal and sensory information into high-order memory representations.

scholarly journals Hippocampal Synaptic Plasticity, Spatial Memory, and Neurotransmitter Receptor Expression Are Profoundly Altered by Gradual Loss of Hearing Ability

2020 ◽  
Vol 30 (8) ◽  
pp. 4581-4596 ◽  
Author(s):  
Daniela Beckmann ◽  
Mirko Feldmann ◽  
Olena Shchyglo ◽  
Denise Manahan-Vaughan
Keyword(s):  
Synaptic Plasticity ◽  
Spatial Memory ◽  
Metabotropic Glutamate Receptor ◽  
Sensory Modality ◽  
Sensory Information ◽  
Receptor Expression ◽  
Sensory Loss ◽  
Hippocampal Function ◽  
Hippocampal Synaptic Plasticity ◽  
Loss Of Hearing

Abstract Sensory information comprises the substrate from which memories are created. Memories of spatial sensory experience are encoded by means of synaptic plasticity in the hippocampus. Hippocampal dependency on sensory information is highlighted by the fact that sudden and complete loss of a sensory modality results in an impairment of hippocampal function that persists for months. Effects are accompanied by extensive changes in the expression of neurotransmitter receptors in cortex and hippocampus, consistent with a substantial adaptive reorganization of cortical function. Whether gradual sensory loss affects hippocampal function is unclear. Progressive age-dependent hearing loss (presbycusis) is a risk factor for cognitive decline. Here, we scrutinized C57BL/6 mice that experience hereditary and cumulative deafness starting in young adulthood. We observed that 2–4 months postnatally, increases in the cortical and hippocampal expression of GluN2A and GluN2B subunits of the N-methyl-D-aspartate receptor occurred compared to control mice that lack sensory deficits. Furthermore, GABA and metabotropic glutamate receptor expression were significantly altered. Hippocampal synaptic plasticity was profoundly impaired and mice exhibited significant deficits in spatial memory. These data show that during cortical adaptation to cumulative loss of hearing, plasticity-related neurotransmitter expression is extensively altered in the cortex and hippocampus. Furthermore, cumulative sensory loss compromises hippocampal function.

Relation Between Level of Prefrontal Activity and Subject's Performance

1999 ◽  
Vol 13 (2) ◽  
pp. 117-125 ◽  
Author(s):  
Laurence Casini ◽  
Françoise Macar ◽  
Marie-Hélène Giard
Keyword(s):  
Brain Activity ◽  
Sensory Information ◽  
Practice Phase ◽  
Trained Subjects ◽  
Anagram Task ◽  
Economic Information ◽  
Long Duration ◽  
Level Of Activity ◽  
The Brain ◽  
Processing Mechanism

Abstract The experiment reported here was aimed at determining whether the level of brain activity can be related to performance in trained subjects. Two tasks were compared: a temporal and a linguistic task. An array of four letters appeared on a screen. In the temporal task, subjects had to decide whether the letters remained on the screen for a short or a long duration as learned in a practice phase. In the linguistic task, they had to determine whether the four letters could form a word or not (anagram task). These tasks allowed us to compare the level of brain activity obtained in correct and incorrect responses. The current density measures recorded over prefrontal areas showed a relationship between the performance and the level of activity in the temporal task only. The level of activity obtained with correct responses was lower than that obtained with incorrect responses. This suggests that a good temporal performance could be the result of an efficacious, but economic, information-processing mechanism in the brain. In addition, the absence of this relation in the anagram task results in the question of whether this relation is specific to the processing of sensory information only.

Wechsler Memory Scale, Rivermead Behavioral Memory Test, and Everyday Memory Questionnaire in Healthy Adults and Alzheimer Patients

2002 ◽  
Vol 18 (1) ◽  
pp. 63-77 ◽  
Author(s):  
Anastasia Efklides ◽  
Efterpi Yiultsi ◽  
Theopisti Kangellidou ◽  
Fotini Kounti ◽  
Fotini Dina ◽  
...  
Keyword(s):  
Spatial Memory ◽  
Semantic Memory ◽  
Memory Test ◽  
Healthy Adults ◽  
Gender Effects ◽  
Everyday Memory ◽  
Wechsler Memory Scale ◽  
Everyday Memory Questionnaire ◽  
Behavioral Memory ◽  
Memory Questionnaire

Summary: The Wechsler Memory Scale (WMS) is a laboratory-based memory test that has been criticized for its lack of ecological validity and for not testing long-term memory. A more recent memory test, which aims at testing everyday memory, is the Rivermead Behavioral Memory Test (RBMT); it tests prospective memory and other forms of memory not tapped by WMS. However, even this test does not capture all aspects of everyday memory problems often reported by adults. These problems are the object of the Everyday Memory Questionnaire (EMQ). This study aimed at identifying the relationships between these three memory tests. The differential effect of Alzheimer's disease (AD) on the above relationships was also studied. The sample consisted of 233 healthy adults (20 to 75+ years of age) and 39 AD patients (50 to 75 years of age). Confirmatory factor analysis revealed the following latent factors: Verbal Memory, Visual Reconstruction, Orientation, Message (action embedded in spatial context), Visual Recognition, Spatial Memory, New Learning/Association Forming, Prospective/Episodic Memory, and Metamemory. These first-order factors were further explained by two second-order factors: Semantic Memory and Coordination of Semantic and Visuo-Spatial Memory. This basic structure was preserved in the sample of AD patients, although AD patients performed less well on the WMS and the RBMT. Some interesting findings regarding semantic memory, face recognition, and metamemory in AD patients are also reported. Age, education, but no gender effects on memory performance were also detected.

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