scholarly journals A retrograde mechanism coordinates memory allocation across brain regions

2021 ◽  
Author(s):  
Ayal Lavi ◽  
Megha Sehgal ◽  
Fardad Sisan ◽  
Anna Okabe ◽  
Donara Ter-Mkrtchyan ◽  
...  
Keyword(s):  
Brain Region ◽  
Basolateral Amygdala ◽  
Memory Performance ◽  
Insular Cortex ◽  
Brain Regions ◽  
Retrograde Tracing ◽  
The Other ◽  
Memory Allocation ◽  
Mathematical Simulations ◽  
Presynaptic Neurons

Memories engage ensembles of neurons across different brain regions within a memory system. However, it is unclear whether the allocation of a memory to these ensembles is coordinated across brain regions. To address this question, we used CREB expression to bias memory allocation in one brain region, and rabies retrograde tracing to test memory allocation in connected presynaptic neurons in the other brain regions. We find that biasing allocation of CTA memory in the basolateral amygdala (BLA) also biases memory allocation in presynaptic neurons of the insular cortex (IC). By manipulating the allocation of CTA memory to specific neurons in both BLA and IC, we found that we increased their connectivity and enhanced CTA memory performance. These results, which are corroborated by mathematical simulations and by studies with auditory fear conditioning, demonstrate that a retrograde mechanism coordinates the allocation of memories across different brain regions.

scholarly journals Chronic Distress in Male Mice Impairs Motivation Compromising Both Effort and Reward Processing With Altered Anterior Insular Cortex and Basolateral Amygdala Neural Activation

2021 ◽  
Vol 15 ◽  
Author(s):  
Lidia Cabeza ◽  
Bahrie Ramadan ◽  
Stephanie Cramoisy ◽  
Christophe Houdayer ◽  
Emmanuel Haffen ◽  
...  
Keyword(s):  
Decision Making ◽  
Basolateral Amygdala ◽  
Insular Cortex ◽  
Brain Regions ◽  
Reward Processing ◽  
Postmortem Brain ◽  
Decision Making Under Uncertainty ◽  
Neural Activation ◽  
Male Mice ◽  
Anterior Insular Cortex

In humans and mammals, effort-based decision-making for monetary or food rewards paradigms contributes to the study of adaptive goal-directed behaviours acquired through reinforcement learning. Chronic distress modelled by repeated exposure to glucocorticoids in rodents induces suboptimal decision-making under uncertainty by impinging on instrumental acquisition and prompting negative valence behaviours. In order to further disentangle the motivational tenets of adaptive decision-making, this study addressed the consequences of enduring distress on relevant effort and reward-processing dimensions. Experimentally, appetitive and consummatory components of motivation were evaluated in adult C57BL/6JRj male mice experiencing chronic distress induced by oral corticosterone (CORT), using multiple complementary discrete behavioural tests. Behavioural data (from novelty suppressed feeding, operant effort-based choice, free feeding, and sucrose preference tasks) collectively show that behavioural initiation, effort allocation, and hedonic appreciation and valuation are altered in mice exposed to several weeks of oral CORT treatment. Additionally, data analysis from FosB immunohistochemical processing of postmortem brain samples highlights CORT-dependent dampening of neural activation in the anterior insular cortex (aIC) and basolateral amygdala (BLA), key telencephalic brain regions involved in appetitive and consummatory motivational processing. Combined, these results suggest that chronic distress-induced irregular aIC and BLA neural activations with reduced effort production and attenuated reward value processing during reinforcement-based instrumental learning could result in maladaptive decision-making under uncertainty. The current study further illustrates how effort and reward processing contribute to adjust the motivational threshold triggering goal-directed behaviours in versatile environments.

scholarly journals Brain Region-Dependent Effects of Neuropeptide Y on Conditioned Social Fear and Anxiety-Like Behavior in Male Mice

2021 ◽  
Vol 22 (7) ◽  
pp. 3695
Author(s):  
Johannes Kornhuber ◽  
Iulia Zoicas
Keyword(s):  
Neuropeptide Y ◽  
Brain Region ◽  
Basolateral Amygdala ◽  
Dorsal Hippocampus ◽  
Brain Regions ◽  
Dependent Manner ◽  
Contextual Fear ◽  
Social Fear ◽  
Fear And Anxiety ◽  
The Brain

Neuropeptide Y (NPY) has anxiolytic-like effects and facilitates the extinction of cued and contextual fear in rodents. We have previously shown that the intracerebroventricular administration of NPY reduces the expression of social fear in a mouse model of social fear conditioning (SFC). In the present study, we aimed to identify the brain regions that mediate these effects of NPY. We show that NPY (0.1 nmol/0.2 µL/side) reduces the expression of SFC-induced social fear in a brain-region-dependent manner. In more detail, NPY reduced the expression of social fear when administered into the dorsolateral septum (DLS) and central amygdala (CeA), but not when administered into the dorsal hippocampus (DH), medial amygdala (MeA) and basolateral amygdala (BLA). We also investigated whether the reduced expression of social fear might partly be due to a reduced anxiety-like behavior, and showed that NPY exerted anxiolytic-like effects when administered into the DH, DLS, CeA and BLA, but not when administered into the MeA. This study identifies the DLS and the CeA as brain regions mediating the effects of NPY on the expression of social fear and suggests that partly distinct neural circuitries mediate the effects of NPY on the expression of social fear and on anxiety-like behavior.

scholarly journals Chronic distress in male mice impairs motivation compromising both effort and reward processing with altered anterior insular cortex and basolateral amygdala neural activation

2021 ◽  
Author(s):  
Lidia Cabeza ◽  
Bahrie Ramadan ◽  
Stephanie Cramoisy ◽  
Christophe Houdayer ◽  
Emmanuel Haffen ◽  
...  
Keyword(s):  
Decision Making ◽  
Basolateral Amygdala ◽  
Insular Cortex ◽  
Brain Regions ◽  
Reward Processing ◽  
Postmortem Brain ◽  
Decision Making Under Uncertainty ◽  
Neural Activation ◽  
Male Mice ◽  
Anterior Insular Cortex

In humans and mammals, effort-based decision-making for monetary or food rewards paradigms contribute to the study of adaptive goal-directed behaviours acquired through reinforcement learning. Chronic distress modelled by repeated exposure to glucocorticoids in rodents induces suboptimal decision-making under uncertainty by impinging on instrumental acquisition and prompting negative valence behaviours. In order to further disentangle the motivational tenets of adaptive decision-making, this study addressed the consequences of enduring distress on relevant effort and reward processing dimensions. Experimentally, appetitive and consummatory components of motivation were evaluated in adult C57BL/6JRj male mice experiencing chronic distress induced by oral corticosterone (CORT), using multiple complementary discrete behavioural tests. Behavioural data (from Novelty Supressed Feeding, operant effort-based choice, Free Feeding and Sucrose Preference tasks) collectively show that behavioural initiation, effort allocation and hedonic appreciation and valuation are altered in mice exposed to several weeks of oral CORT treatment. Additionally, data analysis from FosB immunohistochemical processing of postmortem brain samples highlight a CORT-dependent dampening of neural activation in the anterior insular cortex (aIC) and basolateral amygdala (BLA), key telencephalic brain regions involved in cue appetitive and consummatory motivational processing. Combined, these results suggest that chronic distress-induced irregular aIC and BLA neural activations with reduced effort production and attenuated reward value processing during reinforcement-based instrumental learning could result in maladaptive decision-making under uncertainty. The current study further illustrates how the stoichiometry of effort and reward processing contributes to dynamically adjust the motivational threshold triggering goal-directed behaviours in versatile environments.

scholarly journals 439 - Sex-dependent increase of cerebral blood flow in cortex and hippocampus as a compensatory mechanism in end-of-life dementia: A MRI-ASL translational approach in models of normal and pathological aging

2020 ◽  
Vol 32 (S1) ◽  
pp. 157-157
Author(s):  
A Muntsant-Soria ◽  
F Jiménez-Altayó ◽  
E Jiménez-Xarrié ◽  
L Giménez-Llort
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
End Of Life ◽  
Brain Region ◽  
Memory Performance ◽  
Brain Regions ◽  
Compensatory Mechanism ◽  
Functional Impairments ◽  
Time Asymmetry ◽  
Brain Functions

Alzheimer’s disease (AD) is associated with brain oxidative stress, inflammation, and cerebrovascular disease. Structural and functional abnormalities in cerebral microvasculature have been described in both patients and animals models. New tools and biomarkers for the detection of the disease are still emerging, such as Arterial Spin Labeling (ASL), a magnetic resonance imaging (MRI) technique for non-invasive measurements of cerebral blood blow (CBF) whose alteration may be involved in AD-pathogenesis. Nevertheless, more studies in the field are needed since both hypoperfusion and hyperperfusion in different brain areas are reported and can be involved in different brain functions. Recently, we reported in our colony of 3xTg-AD mice modeling Alzheimer’s disease a higher number of β-amyloid plaques in the hippocampus and entorhinal cortex in middle-aged females and extensive regions of hypoxia which were not seen in males. In the present study, we evaluated CBF in five different brain regions (hippocampus, cortex, striatum, caudate putamen and amygdala) in older male and female surviving until very advanced-stages of disease and as compared with age-matched counterparts with normal aging. AD-phenotype was evaluated by a comprehensive screening of three main functional impairments: physical (frailty), BPSD-like and cognitive deficits. CBF was measured using MRI-ASL and meaningful correlations between AD-phenotype and CBF were performed to better understand the relation between the level of perfusion and frailty, the BPSD-like behaviors and cognitive impairments. The results indicated sex- and brain region-associated changes in CBF. Among all, 3xTg-AD female mice survivors had increased CBF in cortex and hippocampus as compared with their wildtype counterparts. Here, we also report, for the first time, asymmetry between left -right hemispheres in the female’s cortex, in the hippocampus of control males and 3xTg-AD females, as well as in the striatum of control females. Cortex was the area that better correlated with behavior, with asymmetry being associated with worse memory performance. Moreover, hemisphere CBF asymmetry in limbic system was related with copying-with-stress strategies and associated locomotor activity in anxiety tests. The present study suggests a potential compensatory hemodynamic mechanism in end-of-life dementia which is sex- and brain region dependent and can be target for pharmacological and non-pharmacological interventions.

Inefficient Encoding as an Explanation for Age-Related Deficits in Recollection-Based Processing

2014 ◽  
Vol 28 (3) ◽  
pp. 148-161 ◽  
Author(s):  
David Friedman ◽  
Ray Johnson
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Cognitive Processes ◽  
Brain Activity ◽  
Memory Performance ◽  
Brain Regions ◽  
Semantic Retrieval ◽  
Age Related ◽  
The Face ◽  
Episodic Memories

A cardinal feature of aging is a decline in episodic memory (EM). Nevertheless, there is evidence that some older adults may be able to “compensate” for failures in recollection-based processing by recruiting brain regions and cognitive processes not normally recruited by the young. We review the evidence suggesting that age-related declines in EM performance and recollection-related brain activity (left-parietal EM effect; LPEM) are due to altered processing at encoding. We describe results from our laboratory on differences in encoding- and retrieval-related activity between young and older adults. We then show that, relative to the young, in older adults brain activity at encoding is reduced over a brain region believed to be crucial for successful semantic elaboration in a 400–1,400-ms interval (left inferior prefrontal cortex, LIPFC; Johnson, Nessler, & Friedman, 2013 ; Nessler, Friedman, Johnson, & Bersick, 2007 ; Nessler, Johnson, Bersick, & Friedman, 2006 ). This reduced brain activity is associated with diminished subsequent recognition-memory performance and the LPEM at retrieval. We provide evidence for this premise by demonstrating that disrupting encoding-related processes during this 400–1,400-ms interval in young adults affords causal support for the hypothesis that the reduction over LIPFC during encoding produces the hallmarks of an age-related EM deficit: normal semantic retrieval at encoding, reduced subsequent episodic recognition accuracy, free recall, and the LPEM. Finally, we show that the reduced LPEM in young adults is associated with “additional” brain activity over similar brain areas as those activated when older adults show deficient retrieval. Hence, rather than supporting the compensation hypothesis, these data are more consistent with the scaffolding hypothesis, in which the recruitment of additional cognitive processes is an adaptive response across the life span in the face of momentary increases in task demand due to poorly-encoded episodic memories.

scholarly journals Resting‐State EEG Microstates Parallel Age‐Related Differences in Allocentric Spatial Working Memory Performance

2021 ◽  
Author(s):  
Adeline Jabès ◽  
Giuliana Klencklen ◽  
Paolo Ruggeri ◽  
Christoph M. Michel ◽  
Pamela Banta Lavenex ◽  
...  
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Resting State ◽  
Cognitive Aging ◽  
Temporal Dynamics ◽  
Spatial Working Memory ◽  
Brain Activity ◽  
Memory Performance ◽  
Brain Regions ◽  
Age Related

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.

scholarly journals Antibiotics-induced intestinal dysbacteriosis caused behavioral alternations and neuronal activation in different brain regions in mice

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Pan Wang ◽  
Ke Tu ◽  
Peng Cao ◽  
Yuefan Yang ◽  
Hao Zhang ◽  
...  
Keyword(s):  
Mechanical Allodynia ◽  
Neuroprotective Effect ◽  
Memory Performance ◽  
Mechanistic Explanation ◽  
Brain Regions ◽  
Basic Knowledge ◽  
Spontaneous Pain ◽  
Oral Antibiotic ◽  
Microbial Composition ◽  
Intestinal Dysbacteriosis

AbstractAntibiotics affect gut microbial composition, leading to Gut–Brain-Axis imbalance and neurobehavioral changes. However, the intestinal dysbacteriosis associated behavior changes are not consistently reported. It is not clear whether these changes are transient or permanent. The neuroprotective effect of probiotics against intestinal dysbacteriosis induced alternations needs to be determined either. In the present study, oral antibiotic mixture including Ampicillin, Streptomycin, and Clindamycin was utilized to induce intestinal dysbacteriosis in mice. Antibiotics application triggered mechanical allodynia in von frey test and spontaneous pain in open field test. It also resulted in increased anxiety and depressive-like behaviors and damaged spatial memory performance. After application of probiotics, the mechanical allodynia and spontaneous pain were alleviated significantly. The anxiety behaviors, depressive-like behaviors and recognitive performance were ameliorative as well. By using Fos protein as a marker, it is found that the sensory, emotion and memory related brain regions were activated in mice with intestinal dysbacteriosis. Our study is not only helpful for enriching our basic knowledge for understanding the changed pain responses and related brain disorders in antibiotics-induced dysbacteriosis mice, but also beneficial for providing a more comprehensive mechanistic explanation for the regulation of antibiotics and probiotics on gut microbiota and relevant alternations in animal neurological behaviors.

Semiautomatic brain region extraction: a method of parcellating brain regions from structural magnetic resonance images

NeuroImage ◽  
2004 ◽  
Vol 22 (4) ◽  
pp. 1492-1502 ◽  
Author(s):  
L.A Dade ◽  
F.Q Gao ◽  
N Kovacevic ◽  
P Roy ◽  
C Rockel ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Brain Region ◽  
Brain Regions ◽  
Magnetic Resonance Images ◽  
Region Extraction

Abstract 306: Alamandine but not angiotensin-(1-7) produces cardiovascular effects in the Insular Cortex

Hypertension ◽  
2014 ◽  
Vol 64 (suppl_1) ◽  
Author(s):  
Fernanda R Marins ◽  
Aline C Oliveira ◽  
Fatimunnisa Qadri ◽  
Natalia Alenina ◽  
Michael Bader ◽  
...  
Keyword(s):  
Brain Region ◽  
Insular Cortex ◽  
Cardiovascular Effects ◽  
Endogenous Ligand ◽  
Renal Nerve ◽  
Renal Sympathetic Nerve Activity ◽  
Equimolar Dose ◽  
The Brain ◽  
Renal Sympathetic ◽  
Made In

In the course of experiments aimed to evaluate the immunofluorescence distribution of MrgD receptors we observed the presence of immunoreactivity for the MrgD protein in the Insular Cortex. In order to evaluate the functional significance of this finding, we investigated the cardiovascular effects produced by the endogenous ligand of MrgD, alamandine, in this brain region. Urethane (1.4g/kg) anesthetized rats were instrumented for measurement of MAP, HR and renal sympathetic nerve activity (RSNA). Unilateral microinjection of alamandine (40 pmol/100nl), Angiotensin-(1-7) (40pmol/100nl), Mas/MrgD antagonista D-Pro7-Ang-1-7 (50pmol/100nl), Mas agonist A779 (100 pmol/100nl) or vehicle (0,9% NaCl) were made in different rats (N=4-6 per group) into posterior insular cortex (+1.5mm rostral to the bregma). Microinjection of alamandine in this region produced a long-lasting (> 18 min) increase in MAP (Δ saline= -2±1 vs. alamandine= 12±2 mmHg, p< 0.05) associated to increases in HR (Δ saline= 2±2 vs. alamandine= 35±5 bpm; p< 0.05) and in the amplitude of renal nerve discharges (Δ saline = -2±1 vs. alamandine= 35±5.5 % of the baseline; p< 0.05). Strikingly, an equimolar dose of angiotensin-(1-7) did not produce any change in MAP or HR (Δ MAP=-0.5±0.3 mmHg and +2.7±1.2 bpm, respectively; p> 0.05) and only a slight increase in RSNA (Δ =7.3±3.2 %) . In keeping with this observation the effects of alamandine were not significantly influenced by A-779 (Δ MAP=+13± 2.5 mmHg, Δ HR= +26±3.6 bpm; Δ RSNA = 25± 3.4%) but completely blocked by the Mas/MrgD antagonist D-Pro7-Ang-(1-7) (Δ MAP=+0 ± 1 mmHg Δ HR= +4±2.6 bpm; Δ RSNA = 0.5± 2.2 %). Therefore, we have identified a brain region in which alamandine/MrgD receptors but not Ang-(1-7)/Mas could be involved in the modulation of cardiovascular-related neuronal activity. This observation also suggests that alamandine might possess unique effects unrelated to Ang-(1-7) in the brain.

Semantic Congruency Improves Recognition Memory Performance for Both Audiovisual and Visual Stimuli

2017 ◽  
Vol 30 (7-8) ◽  
pp. 763-781 ◽  
Author(s):  
Jenni Heikkilä ◽  
Kimmo Alho ◽  
Kaisa Tiippana
Keyword(s):  
Recognition Memory ◽  
Congruency Effect ◽  
Memory Performance ◽  
Visual Stimuli ◽  
The Other ◽  
Memory Encoding ◽  
Semantic Congruency ◽  
Recognition Memory Performance ◽  
Visual Encoding ◽  
Per Se

Audiovisual semantic congruency during memory encoding has been shown to facilitate later recognition memory performance. However, it is still unclear whether this improvement is due to multisensory semantic congruency or just semantic congruencyper se. We investigated whether dual visual encoding facilitates recognition memory in the same way as audiovisual encoding. The participants memorized auditory or visual stimuli paired with a semantically congruent, incongruent or non-semantic stimulus in the same modality or in the other modality during encoding. Subsequent recognition memory performance was better when the stimulus was initially paired with a semantically congruent stimulus than when it was paired with a non-semantic stimulus. This congruency effect was observed with both audiovisual and dual visual stimuli. The present results indicate that not only multisensory but also unisensory semantically congruent stimuli can improve memory performance. Thus, the semantic congruency effect is not solely a multisensory phenomenon, as has been suggested previously.

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