Stronger left-hemisphere lateralization in older versus younger adults while processing conventional metaphors

Thirty younger (age 20–30) and 30 older (age 69–85) right-handed Hebrew speakers performed a semantic judgement task while processing literal word pairs and conventional metaphors, presented in the divided visual field paradigm. Older adults responded more accurately to conventional metaphors in the right visual field/left hemisphere versus the left visual field/right hemisphere, whereas younger adults showed no lateralization. Vocabulary scores cancelled group differences in lateralization. An additional lexical decision task replicated the main finding of left-hemisphere lateralization in older but not in younger participants. We suggest that accumulated knowledge increases left-hemisphere lateralization on tasks of language comprehension in older relative to younger adults.     

Progressive language impairments: Intervention and management

Background: This paper reviews the role of deliberative processes in language: those language processes that require central resources, in contrast to the automatic processes of lexicalisation, word retrieval, and parsing.

Aims: We describe types of deliberative processing, and show how these processes underpin high-level processes that feature strongly in language. We focus on metalinguistic processing, strategic processing, inhibition, and planning. We relate them to frontal-lobe function and the development of the fronto-striate loop. We then focus on the role of deliberative processes in normal and pathological development and ageing, and show how these processes are particularly susceptible to deterioration with age. In particular, many of the commonly observed language impairments encountered in ageing result from a decline in deliberative processing skills rather than in automatic language processes.

Main Contribution: We argue that central processing plays a larger and more important role in language processing and acquisition than is often credited.

Conclusions: Deliberative language processes permeate language use across the lifespan. They are particularly prone to age-related loss. We conclude by discussing implications for therapy.     

Immunohistochemical changes related to ageing in the mouse hippocampus and subventricular zone

We investigated mainly immunohistochemical changes of nestin (a marker of neuroepithelial stem cells) and Ki-67 (a marker of proliferating cells) proteins related to ageing in the mouse hippocampus and subventricular zone (SVZ) using young adult (8 weeks old) and middle-aged (40 weeks old) mice. In the present study, no significant changes in neurons and astrocytes of the hippocampal CA1 sector were found in a middle-aged male ICR mice without severe senile weakness, as compared with young adult animals. In contrast, a significant change in the number of microglia was found in the hippocampal CA1 sector of the middle-aged mice. Furthermore, no significant changes in the number of nestin- and Ki-67-positive cells were observed in the hippocampal CA1 sector of the middle-aged mice. On the other hand, decreases in the number of nestin- and Ki-67-immunopositive cells were observed in the SVZ of the middle-aged mice. Furthermore, a migration of nestin- and Ki-67-immunoreactive cells in the corpus callosum was not observed in the SVZ of the middle-aged mice. In the dentate gyrus, significant decreases in the number of Ki-67-immunopositive cells were observed in the middle-aged mice. Our study also showed that nestin immunoreactivity was observed in both Ki-67-postive cells and astrocytes in the SVZ of young adult mice. These findings emphasize the need to recognize ageing as important factors in studies of microglia, which may help to clarify the role of glial cell structure and function during ageing processes. Furthermore, the present findings suggest that ageing processes may decrease neurogenesis in the corpus callosum, SVZ and dentate gyrus. Thus our present findings provide valuable information for the neurogenesis during ageing processes.     

Association Between Potentially Inappropriate Medications and Frailty in the Early Old Age: A Longitudinal Study in the GAZEL Cohort

Objectives

High-risk prescribing can have deleterious effects on the health of older people. This study aimed to assess the role of inappropriate prescribing on changes in frailty status over 3 years of follow-up.

Pleurotus ostreatus,an edible mushroom,enhances glucose 6-phosphate dehydrogenase,ascorbate peroxidase and reduces xanthine dehydrogenase in major organs of aged rats

Context: Aging is now considered to be associated with an elevation in oxidative damage to macromolecules and enhanced levels of inflammation. Therefore, inhibition of age-related oxidative stress by natural supplement is an important study.

Objectives: To investigate whether the treatment with Pleurotus ostreatus (Jacq.: Fr) Kumm, (Pleurotaceae) can ameliorate oxidative damage in aged rats.

Materials and methods: Male Wistar rats were divided into three groups of six each: group 1, normal young rats; group 2, normal aged untreated rats; group 3, normal aged rats treated with P. ostreatus (200?mg/kg body wt administered intraperitoneally for 21 days). On the 22nd day, rats were sacrificed by decapitation; the liver, kidneys, heart and brain were removed from each rat for the biochemical and isozyme analyses of the antioxidant enzymes glucose 6-phosphate dehydrogenase (G6PDH), ascorbate peroxidase (Apx) and xanthine dehydrogenase (XDH).

Results: An elevated activity of XDH was observed in the liver (G2:13.72?±?4.1 versus G1: 7.57?±?1.15; p?p?p?p?P. ostreatus to aged rats resulted in decreased XDH and increased G6PDH and Apx activities in liver, kidneys, heart and brain. Interestingly, analyses of isozyme pattern of these enzymes are support the results obtained from the spectrophotometric determinations.

Conclusion: These results suggest that an extract of P. ostreatus can protect the age-related oxidative damage in major organs of Wistar rats by enhancing the antioxidant enzymes G6PDH and Apx and by reducing XDH.     

Balance control interferes with the tracing performance of a pattern with mirror-reversed vision in older persons

GeroScience - When tracing a template with mirror-reversed vision (or distorted vision), the sensory information arising from the movement does not match the expected sensory consequences. In such...     

A mechanistic model of mismatch negativity in the ageing brain

ObjectiveWe investigated the neurophysiological mechanisms underpinning the generation of the mismatch negativity (MMN) in the ageing brain.MethodsWe used dynamic causal modelling (DCM) to study connectivity models for healthy young and old subjects. MMN was elicited with an auditory odd-ball paradigm in two groups of healthy subjects with mean age 74 (n = 30) and 26 (n = 26). DCM was implemented using up to five cortical nodes. We tested models with different hierarchical complexities.ResultsWe showed that the network generating MMN consisted of 5 nodes that could modulate all intra- and inter-nodal connections. The inversion of this model showed that old subjects had increased input from rSTG to the rIFG (p < 0.01) together with increased inhibition of pyramidal cells (p < 0.05). Furthermore, there was reduced modulation of activity within rIFG (p < 0.02) on stimulus change.ConclusionThe age related change in MMN is due to a decline in frontal-based control mechanisms, with alterations in connectivity between temporal and frontal regions together with a dysregulation of the excitatory–inhibitory balance in the rIFG.SignificanceThis study provides for the first time a neurobiological explanation for the age related changes of the MMN in the ageing brain.