Molecular Mechanisms Associated with the Benefits of Variable Practice in Motor Learning

Abstract

Variable practice promotes a higher level of motor learning than constant practice. The glutamate receptors, n-methyl-d-aspartate (NMDA) and alfa-amino-3-hydroxy-5-methyl-4-isoxazolepropionic (AMPA), have been associated with the changes in motor cortex that occur throughout the process of motor learning. Considering that, it is possible that variable practice is more associated with the NMDA and AMPA receptors than constant practice. This study aimed ao investigating the association between the glutamate receptors, NMDA and AMPA, and constant and variable practice schedules. Seventy-eight male mice practiced the rotarod task in a constant or variable scheduling, in two consecutive days (acquisition phase). Learning tests were performed 24?h and 10?days after the end of the acquisition phase. Variable practice was more associated with the NMDA receptor and had a greater AMPA receptor expression than constant practice. The results suggest that the benefits of variable practice are result of both the greater dependency on the NMDA receptor and the greater AMPA receptor expression.     

Differences between girls and boys in emerging language skills: Evidence from 10 language communities

The present study explored gender differences in emerging language skills in 13,783 European children from 10 non‐English language communities. It was based on a synthesis of published data assessed with adapted versions of the MacArthur‐Bates Communicative Development Inventories (CDIs) from age 0.08 to 2.06. The results showed that girls are slightly ahead of boys in early communicative gestures, in productive vocabulary, and in combining words. The difference increased with age. Boys were not found to be more variable than girls. Despite extensive variation in language skills between language communities, the difference between girls and boys remained. This suggests that the difference is caused by robust factors that do not change between language communities.     

Traumatic stress symptoms following a lower limb amputation in diabetic patients: a longitudinal study

Objective: Limited research has focussed on the development of traumatic stress symptoms following an amputation due to a chronic disease such as Diabetes. This study analysed whether coping strategies, anxiety and depression symptoms, sociodemographic and clinical variables were related to traumatic stress symptoms in a sample of patients who had undergone a lower limb amputation.

Design: A longitudinal design with three assessments, one month (T1), six (T2) and ten months after an amputation surgery (T3), included 144 patients.

Main outcome measures: IES-R, WOC and HADS.

Results: Traumatic stress symptoms were prevalent at T1 (M?=?15.65, SD?=?15.40) and probable PTSD was observed in 13.9% patients. Presence of pain, high level of anxiety symptoms and emotion-focused strategies contributed to traumatic stress symptoms, and the period between T1 and T2, was critical. Six to ten months (Λ?=?0.871, F (2,84) =6.245, p=. 003), after surgery, symptoms tended to decrease 0.122 units (SE?=?0.032, p?=?0.002) per assessment.

Conclusions: Findings raise awareness to the need of urgent identification of traumatic stress symptoms in medically ill patients who underwent a lower limb amputation, given the prevalence of traumatic stress symptoms right after surgery and in the following six months.