Role of acetylcholine and serotonin in novelty processing using an oddball paradigm.

The processing of novel stimuli is known to take place in the hippocampus and frontal cortex, and is influenced by the cholinergic system. This ability is crucial to help detect changes in the environment and adapt behaviour accordingly. Previous research has shown that acetylcholine (ACh) can interact with serotonin (5-HT) at the hippocampal level, which may have consequences for cognitive functioning. However, little is known about the exact nature of this ACh and 5-HT interaction as well their possible interactive effects on novelty processing. We investigated the interactive role of ACh and 5-HT in novelty processing in healthy young participants. Levels of these neurotransmitters were manipulated with the muscarinic M1 antagonist biperiden, and with acute tryptophan depletion (ATD). Participants received either placebo, biperiden, ATD, or a combination of both in a double-blind cross-over design. Auditory event-related potentials (ERPs) were recorded while a novelty oddball task was presented. Our results showed that biperiden affected ERP components considered to reflect attentional mechanisms; it increased the P50 amplitude and decreased that of the P200. Furthermore, a decrease of N100 amplitude by ATD was reversed by biperiden. The treatments did not affect the mismatch negativity (MMN) component, which is elicited when a deviant stimulus is presented in a sequence of repetitive stimuli. Importantly, biperiden decreased the amplitude of the ERP component related to novelty processing (P3a). The current study's results did not reveal an interactive effect of ACh and 5-HT on novelty processing. However, the data do suggest that ACh is involved in novelty processing and that it influences basic stimulus processing, without affecting sound-discrimination accuracy.

The Healthy Primary School of the Future: study protocol of a quasi-experimental study.

BACKGROUND: Unhealthy lifestyles in early childhood are a major global health challenge. These lifestyles often persist from generation to generation and contribute to a vicious cycle of health-related and social problems. This design article presents a study evaluating the effects of two novel healthy school interventions. The main outcome measure will be changes in children's body mass index (BMI). In addition, lifestyle behaviours, academic achievement, child well-being, socio-economic differences, and societal costs will be examined. METHODS: In close collaboration with various stakeholders, a quasi-experimental study was developed, for which children of four intervention schools (n = 1200) in the southern part of the Netherlands are compared with children of four control schools (n = 1200) in the same region. The interventions started in November 2015. In two of the four intervention schools, a whole-school approach named 'The Healthy Primary School of the Future', is implemented with the aim of improving physical activity and dietary behaviour. For this intervention, pupils are offered an extended curriculum, including a healthy lunch, more physical exercises, and social and educational activities, next to the regular school curriculum. In the two other intervention schools, a physical-activity school approach called 'The Physical Activity School', is implemented, which is essentially similar to the other intervention, except that no lunch is provided. The interventions proceed during a period of 4 years. Apart from the effectiveness of both interventions, the process, the cost-effectiveness, and the expected legal implications are studied. Data collection is conducted within the school system. The baseline measurements started in September 2015 and yearly follow-up measurements are taking place until 2019. DISCUSSION: A whole-school approach is a new concept in the Netherlands. Due to its innovative, multifaceted nature and sound scientific foundation, these integrated programmes have the potential to form a template for primary schools worldwide. The effects of this approach may extend further than the outcomes associated with well-being and academic achievement, potentially impacting legal and cultural aspects in our society. TRIAL REGISTRATION: The study protocol was registered in the database ClinicalTrials.gov on 14-06-2016 with the reference number NCT02800616 .