Development of the 'SNS older adults measure' (SNS-OA) to examine social network site use in older adults.

OBJECTIVES: Social Networking Sites (SNSs) may ameliorate loneliness in later life but no measure of SNS use for this population exists. This study describes the development of the 'SNS Older Adults measure' (SNS-OA), to improve understanding of older adults' SNS use and its relationship to social wellbeing. METHODS: The SNS-OA underwent initial development, including literature reviews and consultation with target population (n = 9) and experts (n = 9); piloting (n = 74), and evaluation of psychometric properties (n = 263). RESULTS: The final measure comprised three 'motive' scales (using SNSs to maintain close ties, maintain and strengthen weaker ties and diversion), and two 'affect' scales (positive/negative). Whilst many items were weakly endorsed by participants, the measure demonstrated good reliability (Cronbach α = 0.85; ICC = 0.82) and some convergent validity, with some subscales correlating with a personality measure in hypothesised directions. No statistically significant correlations were observed between the measure and social wellbeing. CONCLUSIONS: Despite the measure's limitations, this research has enabled a better understanding of SNS use in older adults and has important implications for research in this area. Findings also suggest a complex relationship between social wellbeing and SNS use in later life.

Mild Behavioral Impairment as a Marker of Cognitive Decline in Cognitively Normal Older Adults.

OBJECTIVE: Mild behavioral impairment (MBI) is a neurobehavioral syndrome characterized by later life emergent neuropsychiatric symptoms (NPS) that represent an at-risk state for incident cognitive decline and dementia in people with mild cognitive impairment (MCI). We undertook a study to determine whether MBI was associated with progressive changes in neuropsychological performance in people without significant cognitive impairment. METHODS: A total of 9,931 older adults enrolled in the PROTECT study who did not have MCI or dementia undertook a comprehensive neuropsychological battery measuring attention, reasoning, executive function, and working memory at baseline and 1 year. MBI was ascertained using self-administration of the Mild Behavioral Impairment Checklist at 1 year, and participants were grouped according to MBI status: No Symptoms, Intermediate NPS and MBI. All assessments were completed online, and data analyzed using mixed-effects model repeated measures analysis of covariance. RESULTS: A total of 949 (10%) people had MBI. These individuals had significantly worse cognitive performance at baseline and significantly greater decline over 1 year in the four composite cognitive scores measuring attentional intensity (F [2,8578] = 3.97; p = 0.019), sustained attention (F [2,8578] = 18.63; p <0.0001), attentional fluctuation (F [2,8578] = 10.13; p <0.0001) and working memory (F [2,9895] = 13.1; p <0.0001). CONCLUSION: Our novel findings show that MBI is associated with faster decline in attention and working memory in this cognitively normal sample. MBI may be an earlier marker of neurodegenerative disease than MCI, captured at the stage of subjective cognitive decline or before, raising the possibility that MBI represents a novel target for dementia clinical trials or prevention strategies.

The relationship between the frequency of number-puzzle use and baseline cognitive function in a large online sample of adults aged 50 and over.

OBJECTIVE: Establishing affordable lifestyle interventions that might preserve cognitive function in the aging population and subsequent generations is a growing area of research focus. Data from the PROTECT study has been utilised to examine whether number-puzzle use is related to cognitive function in older adults. METHODS: Data from 19 078 healthy volunteers aged 50 to 93 years old enrolled on the online PROTECT study were evaluated for self-reported frequency of performing number puzzles. Two cognitive-test batteries were employed to assess core aspects of cognitive function including reasoning, focussed and sustained attention, information processing, executive function, working memory, and episodic memory. Analysis of covariance was used to establish the differences between the six frequency groups. RESULTS: Highly statistically significant main effects of the frequency of performing number puzzles were seen on all 14 cognitive measures, with P values of less than 0.0004. Interestingly, participants who reported engaging in number puzzles more than once a day had superior cognitive performance on 10 core measures compared with all other frequency groups, although not all were statistically significant. CONCLUSIONS: This study has identified a close relationship between frequency of number-puzzle use and the quality of cognitive function in adults aged 50 to 93 years old. In order to determine the value of these findings as a potential intervention, further research should explore the type and difficulty of the number puzzles. These findings further contribute to the growing evidence that engaging in mentally stimulating activities could benefit the brain function of the ageing population.

Synaptic GABA release prevents GABA transporter type-1 reversal during excessive network activity.

GABA transporters control extracellular GABA, which regulates the key aspects of neuronal and network behaviour. A prevailing view is that modest neuronal depolarization results in GABA transporter type-1 (GAT-1) reversal causing non-vesicular GABA release into the extracellular space during intense network activity. This has important implications for GABA uptake-targeting therapies. Here we combined a realistic kinetic model of GAT-1 with experimental measurements of tonic GABAA receptor currents in ex vivo hippocampal slices to examine GAT-1 operation under varying network conditions. Our simulations predict that synaptic GABA release during network activity robustly prevents GAT-1 reversal. We test this in the 0 Mg(2+) model of epileptiform discharges using slices from healthy and chronically epileptic rats and find that epileptiform activity is associated with increased synaptic GABA release and is not accompanied by GAT-1 reversal. We conclude that sustained efflux of GABA through GAT-1 is unlikely to occur during physiological or pathological network activity.

In vitro effects of neuropeptide Y in rat neocortical and hippocampal tissue.

Neuropeptide Y (NPY) network effects in hippocampus and frontal cortex and its impact on epileptiform neocortical discharges were investigated in rat juvenile brain slices. NPY (1 µM) reduced amplitudes of paired pulse stimulation in hippocampal brain tissue (p<0.05) whereas NPY (1 nM-2 µM) had no effect in neocortex. Late stage epileptiform activity in the neocortex was unaffected by NPY (1 µM). Our results point to a region dependent effect of NPY with a high impact on hippocampal and minimal impact on neocortical networks.