Enhancing cognitive flexibility and working memory in individuals with mild cognitive impairment: Exploring the impact of virtual reality on daily life activities.

Mild Cognitive Impairment (MCI) serving as a transitional stage between normal aging and dementia. This study aimed to explore the impact of virtual reality (VR) on enhancing cognitive flexibility, working memory, and daily life activities. Forty participants diagnosed with MCI were randomly assigned to either an intervention group (N = 20) or a control group (N = 20). Evaluations were at baseline, post-training, and three months post-training using various cognitive assessment tools. Results showed that the VR-based cognitive rehabilitation significantly improved instrumental activities of daily living performance, visual and verbal working memory, and reduced anxiety and depression symptoms. While cognitive flexibility did not exhibit significant improvement, these findings highlight VR interventions as a potential avenue for improving cognitive and functional aspects, and alleviating psychological symptoms in individuals with MCI. Further research with larger sample sizes and extended follow-up periods is recommended to establish the long-term effectiveness of such interventions.

Effectiveness of a Virtual-Reality-Based Self-Help Intervention for Lowering the Psychological Burden during the COVID-19 Pandemic: Results from a Randomized Controlled Trial in Iran.

BACKGROUND: The COVID-19 pandemic. In this framework, digital self-help interventions have the potential to provide flexible and scalable solutions for delivering evidence-based treatments that do not necessitate face-to-face meetings. OBJECTIVE: as part of a multicentric project, the purpose of the current randomized controlled trial was to evaluate the efficacy of a Virtual-Reality-based self-help intervention (namely, COVID Feel Good) in lowering the psychological distress experienced during the COVID-19 pandemic in Iran. METHODS: 60 participants were randomly assigned to the experimental (COVID Feel Good intervention group) or the control (no-treatment control group) condition. At the beginning of the intervention (Day 0), at the end of the intervention (Day 7), and after a 2-week follow-up (Day 21), measurements of depressive and anxiety levels, general distress, perceived levels of stress, hopelessness (primary outcome measures), perceived interpersonal closeness with the social world, and fear of COVID-19 (secondary outcome measure) were collected. The protocol consists of two integrated parts: the first part includes a relaxing 10-min three-hundred-sixty-degree (360°) video, while the second one includes social tasks with specified objectives. RESULTS: In terms of the primary outcomes, participants in the COVID Feel Good intervention group improved in depression, stress, anxiety, and perceived stress but not hopelessness. Secondary outcome results showed an improvement in perceived social connectedness and a substantial decrease in fear of COVID-19. CONCLUSIONS: these findings on the efficacy of COVID Feel Good training add to the growing body of evidence demonstrating the feasibility of digital self-help interventions in promoting well-being during this unique period.

The effectiveness of caffeinated chewing gum in ameliorating cognitive functions affected by sleep deprivation.

Objectives: This investigation aimed to compare caffeinated gums with two different dosages of caffeine (200mg vs. 300mg) by assessing their effectiveness on the improvement of cognitive functions among Iranian individuals voluntarily suffering from 30 hours of sleep deprivation. Material and Methods: Thirty-four healthy male volunteers with ages from 28 to 35 years old were randomly assigned to either 200 or 300mg caffeine intake. Each participant completed CANTAB subtests to assess their core cognitive functions including MOT, RTI, RVP, and SWM before and after sleep deprivation, as well as after being treated with caffeinated gum. Results: The 300mg caffeine intake group indicated higher levels of enhancement of core cognitive functions compared with those in the 200mg caffeine intake group. Conclusion: This study suggests that the dose of 300mg of caffeine could effectively enhance the cognitive functions of Iranian individuals suffering from sleep deprivation.

Involvement of D1- and D2-like dopamine receptors in the dentate gyrus in the acquisition, expression, and extinction of the morphine-induced conditioned place preference in rats.

In the current study, we investigated the role of intra-dentate gyrus (DG) administration of D1 and/or D2 receptor antagonists on the expression, acquisition, and extinction of morphine-CPP. Cannulae were implanted bilaterally into the DG region in male Wistar rats and CPP was induced by the subcutaneous injection of morphine (5 mg/kg) during a 3-day conditioning phase. Three experimental designs were separately employed in the CPP paradigm during the acquisition, expression and extinction phases, and different doses (0.25, 1, or 4 µg/0.5 µl saline) of SCH23390, as a selective D1-like receptor antagonist, and sulpiride (0.25, 1, or 4 µg/0.5 µl DMSO), as a selective D2-like receptor antagonist, were bilaterally microinjected into the DG region. Conditioning scores and locomotor activities were recorded during the test. Results showed that the injection of the antagonists into the DG region dose-dependently attenuated the acquisition and expression of the morphine-induced CPP and sulpiride revealed prominent behavioral results compared to SCH23390 in both mentioned phases. Moreover, the blockade of D1- and D2-like receptors shortened the extinction phase of the morphine-induced CPP but had no effect on the locomotor activity. We found that the dopamine receptors within the DG region are involved in the acquisition and expression of morphine-CPP and have a critical role in the association between a morphine-paired context and the rewarding proprieties of morphine.

Role of D1-like and D2-like dopamine receptors within the ventral tegmental area in stress-induced and drug priming-induced reinstatement of morphine seeking in rats.

The ventral tegmental area (VTA) as a major source of dopamine neurons projecting to cortical and limbic regions has a crucial role in reward as well as stress processes. Dopamine is a predominant neurotransmitter in the reward system, which plays an important role in both drug priming-induced and cue-induced reinstatement of cocaine and heroin seeking. It has been shown that this neurotransmitter has a role in stress-induced relapse to drug seeking. Therefore, the present study aims to evaluate the effects of intra-VTA administration of SCH-23390, as a dopamine D1-like receptor antagonist, and sulpiride, as a dopamine D2-like receptor antagonist, on drug priming-induced and food deprivation (FD)-induced reinstatement. The rats were bilaterally implanted by two separate cannulae into the VTA. After the acquisition and extinction of morphine-conditioned place preference, the animals received different doses of SCH-23390 or sulpiride (0.15, 0.4, 1.5 and 4 mg/0.3 µl vehicle per side) into the VTA on the reinstatement day and tested for drug priming-induced reinstatement of morphine (1 mg/kg) or FD-induced reinstatement facilitated by an ineffective dose of morphine (0.5 mg/kg) in separate groups. Our findings indicated that the D1/D2-like receptor antagonists attenuated the drug priming-induced and FD-induced reinstatement. However, these decrements were more significant in groups of animals that received a 24-h FD as a stressor. The data may suggest a role for the VTA dopaminergic system in relapse to drugs of abuse, which may be induced either by re-exposure to morphine or exposure to a stressor.

Role of orexin-1 receptors in the dorsal hippocampus (CA1 region) in expression and extinction of the morphine-induced conditioned place preference in the rats.

Orexinergic system is involved in reward processing and drug addiction. Objectives here, we investigated the effect of intra-hippocampal CA1 administration of orexin-1 receptor (OX1r) antagonist on the expression, and extinction of morphine-induced place preference in rats. Conditioned place preference (CPP) was induced by subcutaneous injection of morphine (5 mg/kg) during a 3-day conditioning phase. Two experimental plots were designed; SB334867 as a selective OX1r antagonist was dissolved in 12% DMSO, prepared in solutions with different concentrations (3, 30, and 300 nM), and microinjected into the CA1 and some neighboring regions (0.5 µl/side), bilaterally. CPP score and locomotor activity were recorded during the CPP test. Results demonstrated that intra-CA1 administration of the OX1r antagonist attenuates the expression of morphine-induced CPP. Furthermore, higher concentrations of SB334867 facilitated the extinction period of morphine-induced CPP and reduced its latency. Nevertheless, solely administration of DMSO did not have any influence on the CPP scores and locomotion in both phases. Our findings suggest that OX1rs in the CA1 region of the hippocampus are involved in the expression of morphine CPP. Moreover, blockade of OX1rs could facilitate extinction and may extinguish the ability of drug-related cues. It seems that the antagonist might be considered as a propitious therapeutic agent in suppressing drug-seeking behaviors.

Role of orexin receptors in the ventral tegmental area on acquisition and expression of morphine-induced conditioned place preference in the rats.

The orexins are hypothalamic neuropeptides and their role in reward processing and drug addiction has been demonstrated. The extent of involvement of each orexin receptor in the acquisition and expression of conditioned place preference (CPP) for morphine is still a matter of controversy. We investigated the functional differences between orexin-1 and -2 receptor blockade in the ventral tegmental area (VTA) on the acquisition and expression of morphine CPP. A total of 86 adult male Wistar rats weighing 250±30g (age 7-8weeks) received intra-VTA microinjection of either SB334867 (0.1, 1 and 10nM), a selective orexin-1 receptor (OX1R) antagonist, or TCS-OX2-29 (1, 5 and 25nM), a selective orexin-2 receptor (OX2R) antagonist. To measure the acquisition, the animals received each antagonist (SB334867 or TCS-OX2-29) 5min prior to subcutaneous injection of morphine (5mg/kg) during the conditioning phase. To measure the CPP expression, the animals received each antagonist on the post-conditioning phase. The CPP conditioning score was recorded by Ethovision software. Data showed that intra-VTA microinjection of OX1-R antagonist significantly attenuated morphine CPP acquisition, during the conditioning phase, and expression, during the post-conditioning phase. Intra-VTA microinjection of OX2-R antagonist also significantly attenuated morphine CPP acquisition and expression in the mentioned phases. Our results showed the orexin role in learning and memory and indicate that orexin receptors (OX1R and OX2R) function in the VTA is essential for both acquisition and expression of morphine reward in rats in the CPP model.