Sensitivity to amphetamine in prepulse inhibition response requires a mature medial prefrontal cortex.

Prepulse inhibition (PPI) refers to the modulation of the startle response by the presentation of a weaker stimulus prior to the onset of the startle stimulus. This response is consolidated along the maturation process of the mesocortical system, where the dopamine neurotransmitter plays an important role. In fact, it has been reported that agonist and antagonist dopaminergic drugs are able to change PPI expression. This study was aimed to analyze the relationship between the adult medial prefrontal cortex (mPfc) and dopaminergic involvement in PPI throughout the life span. Specifically, the present experiment analyzed the effect of the administration of dopaminergic agonist amphetamine on PPI in two different age periods in Wistar rats: postnatal day (PND) 28 and PND 70. In this last period, we also explored the relationship between PPI response and amphetamine effects after mPfc lesion. The results showed that PPI was expressed in all groups and periods; however, amphetamine only modulated this effect during adulthood. We also found that the mPfc is essential to modulate PPI after amphetamine consumption. Besides, our results suggest a role for dopamine and mPfc as important modulators of PPI in adulthood. Nevertheless, this neurotransmitter could not be involved in the expression of PPI because the administration of a dopaminergic agonist was ineffective in PND-28 period. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

The role of vitamin supplementation in the prevention of cardiovascular disease events.

The production, sale, and consumption of multiple vitamins is a multibillion-dollar industry. Most Americans take some form of supplement ostensibly for prevention of cardiovascular disease. It has been claimed that vitamin A retards atherogenesis. Vitamin C is an antioxidant and is thought to possibly decrease free radical-induced endothelial injury, which can lead to atherosclerotic plaque formation. Vitamin E has been extensively studied for its possible effects on platelet function as well as inhibition of foam-cell formation. Low levels of vitamin D have been thought to negatively impact myocardial structure and increase the risk for cardiovascular events. Increased intake of vitamin B6, B12, and folate has been associated with reduction of homocysteine levels; elevated homocysteine blood levels have been associated with the occurrence of stroke, heart attack, and cardiovascular death. The purpose of this study was to review the currently available literature for vitamin supplementation with respect to prevention of cardiovascular disease. Unfortunately, the current evidence suggests no benefit exists with vitamin supplementation in the general US population. Further research is needed to evaluate whether there are specific populations that might benefit from vitamin supplementation.