Insulin signaling effects on memory and mood

Abstract

The escalating obesity/diabetes epidemic is an important health care issue that has critical socioeconomic ramifications. The complications of diabetes/obesity phenotypes extend to the central nervous system, including the hippocampus, a brain region that is particularly vulnerable to hyperglycemia and insulin resistance. Deficits in hippocampal synaptic plasticity observed in diabetes ultimately have deleterious consequences upon cognitive function. For example, recent studies using brain imaging technologies have identified cerebral atrophy in diabetic patients, suggesting that the neuroanatomical changes observed in experimental models of diabetes may accurately reflect what is occurring in the clinical setting. Deficits in insulin receptor signaling and impairments in hypothalamic-pituitary-adrenal (HPA) axis function also contribute to the neurological complications of diabetes phenotypes. The pathophysiological similarities between diabetes and stress-related mood disorders suggest that common mechanistic mediators may be involved in the etiology and progression of the neurological complications of these disorders. When combined with the accumulating evidence from pre-clinical models, these data support the hypothesis that a long-term consequence of diabetes/obesity phenotypes is accelerated brain aging that results in neuropsychological deficits and increased vulnerability to co-morbidities such as depressive illness.

Smart Phone Sensing to Examine Effects of Social Interactions and Non-sedentary Work Time on Mood Changes

“…The survey, which will be presented later in the paper, shows that these short breaks are perceived as pleasant social interactions by participants in our experiments. In addition to social interactions the study was then extended to include sedentary patterns for two reasons: 1) sedentary behavior has been linked with insulin sensitivity [10], lipid metabolism [10] and sympathetic activity [44], which influence the mood, as shown through a number of clinical studies [44,45,46]; thus it was seen as a potential factor that may also affect the mood; 2) related to socialization patterns is also the behavior of workers' during workday, specifically number of overall breaks and their duration. Study of mood changes and factors that influence these changes can provide a good estimation of the general wellbeing of the knowledge workers and avoid lost productive time.…”

The Application of Pectin-Insulin Patch on Streptozotocin-Induced Diabetic Rats: Implications in the Hippocampal Function

“…The effects of insulin in the hippocampus are mediated through insulin receptor signalling and insulin receptors are highly expressed in the hippocampus in comparison to other regions [39]. Defects in insulin signalling corresponds with the onset and progression of dementia [40]. Insulin receptor regulation in diabetes has been reported to be up-regulated possibly due to the lack of insulin which facilitates receptor downregulation [41].…”

“…Animals were exposed to 5 consecutive training sessions for a period of 5 days (day [36][37][38][39][40]. Animals were taken to the behavioural room 1 hour prior to the training to allow for familiarisation to the new environment.…”

Acute effects of 17β-estradiol and genistein on insulin sensitivity and spatial memory in aged ovariectomized female rats

“…Mean±standard error of the mean for seven animals Significant differences are shown a Young versus aged and mood (Reagan 2007), and insulin resistance has also been linked to deficits in spatial memory in obese rats (Jurdak et al 2008). The prevalence of impaired glucose tolerance and type 2 diabetes mellitus increases with age (Meigs et al 2003) not only in humans, but also in models of aging in rats (Barzilai and Rossetti 1995;Reaven and Reaven 1985).…”