Glucocorticoids Decrease Hippocampal and Prefrontal Activation during Declarative Memory Retrieval in Young Men

Glucocorticoids (GCs, cortisol in human) are associated with impairments in declarative memory retrieval. Brain regions hypothesized to mediate these effects are the hippocampus and prefrontal cortex (PFC). Our aim was to use fMRI in localizing the effects of GCs during declarative memory retrieval. Therefore, we tested memory retrieval in 21 young healthy males in a randomized placebo-controlled crossover design. Participants encoded word lists containing neutral and emotional words 1 h prior to ingestion of 20 mg hydrocortisone. Memory retrieval was tested using an old/new recognition paradigm in a rapid event-related design. It was found that hydrocortisone decreased brain activity in both the hippocampus and PFC during successful retrieval of neutral words. These observations are consistent with previous animal and human studies suggesting that glucocorticoids modulate both hippocampal and prefrontal brain regions that are crucially involved in memory processing

Effect of different exercise programs on the psychological and cognitive functions of people with Parkinson's disease

The purpose of this study was to analyze the effect of different exercise programs on the psychological and cognitive functions in patients with Parkinson's disease (PD). Forty-five patients with PD participated in the study. The participants were randomized in three intervention programs: Group-1 (n=15, cognitive-activities), Group-2 (n=15, multimodal exercise) and Group-3 (n=15, exercises for posture and gait). The clinical, psychological and cognitive functions were assessed before and after 4 months of intervention. Univariate analysis did not reveal significant interactions between groups and time (p>0.05). However, univariate analysis for time revealed differences in stress level and memory. Participants showed less physical stress (p<0.01) and overall stress (p < 0.04) and higher performance in episodic declarative memory (p < 0.001) after exercise. These findings suggest that group work with motor or non-motor activities can improve cognitive and psychological functions of patients with PD

Acute Modulation of Aged Human Memory by Pharmacological Manipulation of Glucocorticoids

In a previous longitudinal study of basal cortisol levels and cognitive function in humans, we showed that elderly humans with 4- to 7-yr cumulative exposure to high levels of cortisol present memory impairments, compared with elderly humans with moderate cortisol levels over years. Here, we measured whether memory performance in two groups of elderly humans separated on the basis of their cortisol history over a 5-yr period could be modulated by a hormone-replacement protocol in which we inhibited cortisol secretion by the administration of metyrapone and then restored baseline cortisol levels by infusion of hydrocortisone. We showed that in elderly subjects with a 5-yr history of moderate cortisol levels (n 8), metyrapone treatment significantly impaired memory performance, a deficit that was reversed following hydrocortisone replacement. In the elderly subjects with a 5-yr history of high cortisol levels and current memory deficits (n 9), metyrapone treatment did not have any significant effect on memory performance, but hydrocortisone treatment significantly decreased delayed memory. These results suggest that memory function in elderly humans can be intensely modulated by pharmacological manipulation of glucocorticoids, although the direction of these effects depends on the cortisol history of each individual