Shift in Induction Mechanisms Underlies an Age-Dependent Increase in DHPG-Induced Synaptic Depression at CA3–CA1 Synapses

2007 ◽  
Vol 98 (5) ◽  
pp. 2729-2736 ◽  
Author(s):  
Ashok Kumar ◽  
Thomas C. Foster
Keyword(s):  
Young Adults ◽  
Synaptic Plasticity ◽  
Tyrosine Phosphatase ◽  
Synaptic Depression ◽  
Advanced Age ◽  
Metabotropic Receptor ◽  
Age Related ◽  
Group I ◽  
Enhanced Expression ◽  
Age Related Changes

Several forms of log-term synaptic plasticity have been identified and the mechanisms for induction and expression of synaptic modifications change over development and maturation. The present study examines age-related changes in the induction of group I metabotropic receptor selective agonist ( R, S)-3,5-dihydroxyphenylglycine (DHPG) induced long-term synaptic depression (DHPG-LTD) at CA3–CA1 synapses. The results demonstrate that the magnitude of DHPG-LTD is enhanced in male aged Fischer 344 rats compared with young adults. The role of mGluR1 in the induction of DHPG-LTD was increased with advanced age and, in contrast to young adults, induction involved a significant contribution of NMDA receptors and L-type Ca2+ channels. Moreover, the protein tyrosine phosphatase inhibitor sodium orthovanadate significantly attenuated DHPG-LTD only in young adults. The expression of DHPG-LTD in aged animals was dependent on protein synthesis and the enhanced expression was associated with an increase in paired-pulse facilitation. The results provide evidence that DHPG-LTD is one of the few forms of synaptic plasticity that increases with advanced age and suggest that DHPG-LTD may contribute to age-related changes in hippocampal function.

17β-estradiol modifies stress-induced and age-related changes in hippocampal synaptic plasticity.

2008 ◽  
Vol 122 (2) ◽  
pp. 301-309 ◽  
Author(s):  
Michael R. Foy ◽  
Michel Baudry ◽  
Judith G. Foy ◽  
Richard F. Thompson
Keyword(s):  
Synaptic Plasticity ◽  
Hippocampal Synaptic Plasticity ◽  
Age Related ◽  
17Β Estradiol ◽  
Age Related Changes

scholarly journals Age-related changes in human emotional egocentricity: evidence from multi-level neuroimaging

2019 ◽  
Author(s):  
Federica Riva ◽  
Melanie Lenger ◽  
Martin Kronbichler ◽  
Claus Lamm ◽  
Giorgia Silani
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Life Span ◽  
Emotional State ◽  
Effective Connectivity ◽  
Age Related ◽  
Somatosensory Cortices ◽  
Egocentric Bias ◽  
Multi Level ◽  
Age Related Changes

AbstractEmotional egocentric bias (EEB) occurs when, due to a partial failure in self-other distinction, empathy for another’s emotions is influenced by our own emotional state. Recent studies have demonstrated that this bias is higher in children, adolescents and older adults than in young adults. In the latter, overcoming emotional egocentrism has been associated with significant activity in the right supramarginal gyrus (rSMG), as well as increased connectivity between rSGM and somatosensory and visual cortices. Investigations on the neural correlates of EEB in adolescents and older adults are missing. We filled this gap, by asking female participants from three different age groups (adolescents, young adults and older adults, N=92) to perform a well-validated EEB task (Silani et al., 2013) in an MRI scanner. A multi-level analysis approach of MRI data including functional segregation, effective connectivity and structural analyses was adopted. Results revealed higher EEB in older compared to young adults and a comparable EEB in adolescents and young adults. Age-related differences in EEB were associated with differences in task-related rSMG connectivity with somatosensory cortices, especially with S2, which acted as a partial mediator between age and EEB. These findings provide further evidence for the crucial role of the rSMG in self-other distinction in the emotional domain, and suggest that the age-related decline in overcoming EEB is best explained by changes in rSMG connectivity rather than decreased regional activity in that area. This advocates a more systematic investigation of task-related connectivity in studies on aging and life-span development of social-cognitive phenomena.Significance StatementEmpathy comprises both the ability to identify and share another’s emotional state, and the ability to disentangle one’s own from the other’s emotional state. When self- and other-related emotions are conflicting, empathy might be negatively influenced by egocentric tendencies. This phenomenon is referred to as emotional egocentric bias (EEB), with previous research showing that its extent changes across the life-span. Here, we provide evidence that age-related differences in EEB are mainly associated with age-related changes in rSMG effective connectivity, and in particular that higher EEB in older adults is associated to lower rSMG effective connectivity with somatosensory cortices. These findings suggest the importance, particularly in aging, of intact functional connectivity for optimal socio-cognitive functioning.

scholarly journals I remember it like it was yesterday: Age-related changes in the subjective experience of remembering the past

2020 ◽  
Author(s):  
Adrien Folville ◽  
Jon Simons ◽  
Arnaud D'Argembeau ◽  
Christine Bastin
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Conceptual Knowledge ◽  
Subjective Experience ◽  
Brain Regions ◽  
Future Research ◽  
Subjective Ratings ◽  
Neural Basis ◽  
Age Related ◽  
Age Related Changes

It has been frequently described that older adults subjectively report the vividness of their memories as being as high, or even higher, than young adults, despite poorer objective memory performance and/or lower activity in the associated brain regions. Here, we review studies that examined age-related changes in the cognitive and neural basis of the subjective experience of remembering. Together, these studies reveal that older adults assign subjective memory ratings that are as high or higher than young adults but rely on retrieved memory details to a lesser extent. We discuss potential mechanisms underlying this observation. Overestimation of subjective ratings may stem from metamemory changes, psycho-social factors or methodological issues. As for poorer calibration of the ratings, this may be explained by the fact that older adults rely on/weight other types of information (conceptual knowledge, personal memories, and socioemotional or gist aspects of the memory trace) to a greater extent than young adults when judging the subjective vividness of their memories. We further highlight that a desirable avenue for future research would be to investigate how subjective ratings follow the richness of the corresponding mental representations in other cognitive operations than episodic memory and in other populations than healthy older adults. Finally, we recommend that future studies explore the bases of the subjective sense of remembering across the lifespan while considering recent accounts focusing both on individual and collective/shared aspects of recollection.

scholarly journals Spatial and semantic interference on an auditory Stroop test: comparison of young and older adults

2021 ◽  
Author(s):  
Shubhaganga Dhrruvakumar ◽  
Asha Yathiraj
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Reaction Time ◽  
Spatial Localization ◽  
Stroop Test ◽  
Response Accuracy ◽  
Age Related ◽  
Semantic Localization ◽  
Left Front ◽  
Age Related Changes

Background and Aim: Age related changes in cognitive functioning have been shown to vary depending on the task used. Thus, the study aimed to compare the responses of young and older adults to an auditory Stroop test that asse­ssed spatial (responses to location of the stimuli) and semantic (responses to meaning of the sti­muli) localization. Methods: The “Auditory spatial and semantic localization Stroop test”, developed as a part of the study was administered on 30 young adults aged 18 to 30 years and 30 older adults aged 58 to 70 years having normal hearing. The res­ponse accuracy and reaction time of the parti­cipants were determined for the words “right”, “left”, “front”, and “back.” Results: The older adults had significantly poo­rer response accuracy and reaction time than the young adults for both spatial and semantic loca­lization tasks. Within each participant group, semantic localization had better response accu­racy than spatial localization, while such diffe­rences in reaction time were found only in the older adults. In both groups, a congruency effect was seen for spatial but not for semantic loca­lization when response accuracy was calculated, whereas it was observed only for semantic and not for spatial localization when reaction time was measured. Conclusion: The auditory Stroop test, which measures stimulus interference and cognitive skills, could be used as a simple tool to assess the same for stimuli presented through the audi­tory modality. This would be especially helpful in older adults who may demonstrate cognitive decline with ageing to auditory stimuli. Keywords: Spatial localization; semantic localization; auditory Stroop test; age related changes

scholarly journals POSITION OF HEADS OF TEMPOROMANDIBULAR JOINT IN PATIENTS WITH MALOCCLUSION

2020 ◽  
Vol 20 (3) ◽  
pp. 64-67
Author(s):  
V.D. Kuroiedova ◽  
O.A. Stasiuk ◽  
Ye.Ye. Vyzhenko ◽  
Yu.K. Sokolohorska-Nykina
Keyword(s):  
Temporomandibular Joint ◽  
Permanent Dentition ◽  
Mixed Dentition ◽  
Correct Position ◽  
Rotational Displacement ◽  
Age Related ◽  
Group I ◽  
Number Of Patients ◽  
Left And Right ◽  
Age Related Changes

This article describes the assessment of the condition, symmetry of temporomandibular joint and timely diagnosis of its dysfunction based on to H. Gelb method in malocclusion. The objective of this study was to investigate the position and assess the symmetry of the temporomandibular joint heads according to H. Gelb in cases of malocclusion. Materials and мethods. The study was based on analysis of computed tomographs of 70 patients with malocclusion. Depending on the stage of the occlusion development, the patients were divided into two groups: I group included 30 patients with mixed dentition and II group included 40 patients with permanent dentition. Results. The results obtained demonstrated that regardless of the pathology of the occlusion and age, only 8 patients had the correct bite, i.e. the symmetrical position of the temporomandibular joint heads in the Gelb 4/7 position. The most frequent symmetric position of the articular heads in the patients of the I group I was the Gelb ¼ position found in 16 patients; the Gelb 1/5 position was revealed in 8 patients of the II group that can be explained as age-related changes in the displacement of the articular heads from the Gelb 1/4 to 1/5 position. Conclusions. According to the results of our research, it was found that regardless of the malocclusion and age, patients who have the correct position of the temporomandibular joint heads on the left and right in the Gelb 4/7 position make up only 10.52%. The age-related dynamics of the rotational displacement of the centre of the articular heads from the Gelb 1/4 to 1/5 position has been observed, and the number of patients with the asymmetric position of the temporomandibular joint articular heads is increaing.

scholarly journals Validating the Capability for Measuring Age-Related Changes in Grip-Force Strength Using a Digital Hand-Held Dynamometer in Healthy Young and Elderly Adults

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Shu-Chun Lee ◽  
Li-Chen Wu ◽  
Shang-Lin Chiang ◽  
Liang-Hsuan Lu ◽  
Chao-Ying Chen ◽  
...  
Keyword(s):  
Young Adults ◽  
Grip Force ◽  
The Elderly ◽  
Elderly Adults ◽  
Hand Grip ◽  
Age Related ◽  
Jamar Dynamometer ◽  
Maximum Grip ◽  
Age Related Changes

Background. Grip-force performance can be affected by aging, and hand-grip weakness is associated with functional limitations of dasily living. However, using an appropriate digital hand-held dynamometer with continuous hand-grip force data collection shows age-related changes in the quality of hand-grip force control may provide more valuable information for clinical diagnoses rather than merely recording instantaneous maximal hand-grip force in frail elderly adults or people with a disability. Therefore, the purpose of this study was to indicate the construct validity of the digital MicroFET3 dynamometer with Jamar values for maximal grip-force assessments in elderly and young adults and confirmed age-related changes in the maximal and the quality of grip-force performance using the MicroFET3 dynamometer in elderly people. Methods. Sixty-five healthy young (23.3±4.5 years) and 50 elderly (69.5±5.8 years) adults were recruited and asked to perform a validity test of the grip-force maximum voluntary contraction (MVC) using both the dominant and nondominant hands with a Jamar dynamometer and a MicroFET3 dynamometer. Results. A strong correlation of maximal grip-force measurements was found between the MicroFET3 dynamometer and Jamar standard dynamometer for both hands in all participants (p<0.05). Although, the results showed that a lower grip force was measured in both hands by the MicroFET3 dynamometer than with the Jamar dynamometer by 49.9%~57% (p<0.05), but confidently conversion formulae were also developed to convert MicroFET3 dynamometer values to equivalent Jamar values for both hands. Both dynamometers indicated age-related declines in the maximum grip-force performance by 36.7%~44.3% (p<0.05). We also found that the maximal hand-grip force values generated in both hand by the elderly adults were slower and more inconsistent than those of the young adults when using the MicroFET3 dynamometer. Conclusions. This study demonstrated that the digital MicroFET3 dynamometer has good validity when used to measure the maximal grip force of both hands, and conversion formulae were also developed to convert MicroFET3 dynamometer force values to Jamar values in both hands. Comparing with the Jamar dynamometer for measuring grip force, the MicroFET3 dynamometer not only indicated age-related declines in the maximum grip-force performance but also showed slower and more inconsistent maximal hand-grip strength generation by the elderly.

Age-related changes in the synaptic plasticity of rat superior cervical ganglia

1991 ◽  
Vol 542 (2) ◽  
pp. 324-329 ◽  
Author(s):  
Ruilin Wu ◽  
David G. McKenna ◽  
Donald A. McAfee
Keyword(s):  
Synaptic Plasticity ◽  
Superior Cervical Ganglia ◽  
Age Related ◽  
Cervical Ganglia ◽  
Age Related Changes

Age-Related Changes in Presynaptic Inhibition During Gait Initiation

2021 ◽  
Author(s):  
Solival Santos Filho ◽  
Daniel Boari Coelho ◽  
Carlos Ugrinowitsch ◽  
Caroline Ribeiro de Souza ◽  
Fernando Henrique Magalhães ◽  
...  
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Presynaptic Inhibition ◽  
Gait Initiation ◽  
Quiet Stance ◽  
Age Related ◽  
Contraction Ratio ◽  
Age Range ◽  
Age Related Changes ◽  
Presynaptic Control

Abstract Age-related changes in presynaptic inhibition (PSI) have not been observed during gait initiation, which requires anticipatory postural adjustment (APA). As APA is centrally modulated and is impaired in older compared to young adults, here we aimed to study the presynaptic control and co-contraction levels in the ankle muscles during gait initiation in older compared to young adults. Fifteen older (age range 65–80 years) and 15 young adults (age range 19–30 years) performed a gait initiation task on a force platform under 3 conditions: (i) without electrical stimulation; (ii) test Hoffman reflex (H-reflex); and (iii) conditioned H-reflex. H-reflexes were evoked on the soleus muscle when the APA amplitude exceeded 10%–20% of the average baseline mediolateral force. Participants also performed quiet stance as a control task. Results showed that both age groups presented similar PSI levels during quiet stance (p = .941), while in the gait initiation older adults presented higher PSI levels, longer duration, and lower amplitude of APA than young adults (p &lt; .05). Older adults presented higher co-contraction ratio in both tasks than young adults (p &lt; .05). Correlations between the PSI levels and the APA amplitude (r = −0.61, p = .008), and between the PSI levels and the co-contraction ratio during gait initiation (r = −0.64, p = .005) were found for older adults only. APA amplitude explained 49% of the variance of the PSI levels (p = .003). Our findings suggest that older compared to young adults have increased presynaptic control to compensate for the decreased supraspinal modulation on impaired APAs during gait initiation.

scholarly journals Age‐related changes in hippocampal‐dependent synaptic plasticity and memory mediated by p75 neurotrophin receptor

Aging Cell ◽  
2021 ◽  
Vol 20 (2) ◽  
Author(s):  
Lik‐Wei Wong ◽  
Yee Song Chong ◽  
Wei Lin ◽  
Lilian Kisiswa ◽  
Eunice Sim ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Neurotrophin Receptor ◽  
P75 Neurotrophin Receptor ◽  
Age Related ◽  
Age Related Changes
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