Regional homogeneity of intrinsic brain activity related to the main alexithymia dimensions

Background Alexithymia is a multidimensional personality construct.Objective This study aims to investigate the neuronal correlates of each alexithymia dimension by examining the regional homogeneity(ReHo) of intrinsic brain activity in a resting situation.Methods From university freshmen, students with alexithymia and non-alexlthymia were recruited. Their alexithymic traits were assessed using the Toronto Alexithymia Scale-20. The ReHo was examined using a resting-state functional MRI approach.Results This study suggests significant gro叩 differences in ReHo in multiple brain regions distributed in the frontal lobe, parietal lobe, temporal lobe, occipital lobe and insular cortex. However, only the ReHo in the insula was positively associated with difficulty identifying feelings, a main dimension of alexithymia. The ReHo in the lingual gyrus,precentral gyrus and postcentral gyrus was positively associated with difficulty describing feelings in participants with alexithymia. Lastly, the ReHo in the right dorsomedial prefrontal cortex(DMPFC_R) was negatively related to the externally oriented thinking style of participants with alexithymia.Conclusion In conclusion, these results suggest that the main dimensions of alexithymia are correlated with specific brain regions' function, and the role of the insula,lingual gyrus, precentral gyrus, postcentral gyrus and DMPFC_R in the neuropathology of alexithymia should be further investigated.

Targeting biosignatures of hyperglycemia and oxidative stress in diabetes comorbid depressive rats: effectiveness of hydroethanolic extract of the whole plant of Ludwigia octovalvis

Background:The prime objective of the current research was to evaluate the whole plant hydroalcoholic extract of Ludwigia octovalvis(HLO)against hyperglycemia,and oxidative stress biomarkers in rats induced with diabetes comorbid depression,diabetes comorbid depression(streptozotocin-nicotinamide+electric footshocks).Methods:2,2-Diphenyl-1-picrylhydrazyl assay of HLO versus ascorbic acid was done.Effects of 200 and 400 mg/kg body weight/day HLO doses versus 25 mg/kg body weight/day metformin was studied through insulin,glucose,superoxide dismutase,lipid peroxidation,catalase,and behavioral assessment(forced swim and open field tests).Results:IC50 values of HLO and ascorbic acid were 33.52 and 27.86μg/mL respectively.Both the HLO doses showed intended results with respect to oxidative stress biomarkers in diabetes comorbid depression rats in comparison to metformin.Open field test showed better results for HLO in diabetes comorbid depression rats.However,hypoglycemic effects,and forced swim test performance of metformin was slightly higher than the 400 mg dose,followed by the 200 mg dose of HLO.Ethyl gallate,gallic acid,β-sitosterol,and quercetin in HLO might resulted in attenuating diabetic as well as depression biomarkers.Conclusion:Inhibition of glucosidase and lipase activity,and AMP-activated protein kinase phosphorylation might be the possible biochemical changes occurred in HLO treated rats.

Effects of methylphenidate on resting-state brain activity in normal adults: an fMRI study

Methylphenidate （MPH） is one of the most commonly used stimulants for the treatment of attention deficit hyperactivity disorder （ADHD）. Although several studies have evaluated the effects of MPH on human brain activation during specific cognitive tasks using functional magnetic resonance imaging （fMRI）, few studies have focused on spontaneous brain activity. In the current study, we investigated the effect of MPH on the intra-regional synchronization of spontaneous brain activity during the resting state in 18 normal adult males. A handedness questionnaire and the Wechsler Adult Intelligence Scale were applied before medication, and a resting-state fMRI scan was obtained 1 h after medication （20 mg MPH or placebo, order counterbalanced between participants）. We demonstrated that： （1） there were no significant differences in the performance of behavioral tasks between the MPH and placebo groups; （2） the left middle and superior temporal gyri had stronger MPH-related regional homogeneity （ReHo）; and （3） the left lingual gyrus had weaker MPH-related ReHo. Our findings showed that the ReHo in some brain areas changes with MPH compared to placebo in normal adults, even though there are no behavioral differences. This method can be applied to patients with mental illness who may be treated with MPH, and be used to compare the difference between patients taking MPH and normal participants, to help reveal the mechanism of how MPH works.