Exercise enhances motor skill learning by neurotransmitter switching in the adult midbrain.

Physical exercise promotes motor skill learning in normal individuals and those with neurological disorders but its mechanism of action is unclear. We find that one week of voluntary wheel running enhances the acquisition of motor skills in normal adult mice. One week of running also induces switching from ACh to GABA expression in neurons in the caudal pedunculopontine nucleus (cPPN). Consistent with regulation of motor skills, we show that the switching neurons make projections to the substantia nigra (SN), ventral tegmental area (VTA) and ventrolateral-ventromedial nuclei of the thalamus (VL-VM). Use of viral vectors to override transmitter switching blocks the beneficial effect of running on motor skill learning. We suggest that neurotransmitter switching provides the basis by which sustained running benefits motor skill learning, presenting a target for clinical treatment of movement disorders

Practice Makes Imperfect: Restorative Effects of Sleep on Motor Learning

Emerging evidence suggests that sleep plays a key role in procedural learning, particularly in the continued development of motor skill learning following initial acquisition. We argue that a detailed examination of the time course of performance across sleep on the finger-tapping task, established as the paradigm for studying the effect of sleep on motor learning, will help distinguish a restorative role of sleep in motor skill learning from a proactive one. Healthy subjects rehearsed for 12 trials and, following a night of sleep, were tested. Early training rapidly improved speed as well as accuracy on pre-sleep training. Additional rehearsal caused a marked slow-down in further improvement or partial reversal in performance to observed levels below theoretical upper limits derived on the basis of early pre-sleep rehearsal. This decrement in learning efficacy does not occur always, but if and only if it does, overnight sleep has an effect in fully or partly restoring the efficacy and actual performance to the optimal theoretically achieveable level. Our findings re-interpret the sleep-dependent memory enhancement in motor learning reported in the literature as a restoration of fatigued circuitry specialized for the skill. In providing restitution to the fatigued brain, sleep eliminates the rehearsal-induced synaptic fatigue of the circuitry specialized for the task and restores the benefit of early pre-sleep rehearsal. The present findings lend support to the notion that latent sleep-dependent enhancement of performance is a behavioral expression of the brain's restitution in sleep

Distributed representations accelerate evolution of adaptive behaviours

Animals with rudimentary innate abilities require substantial learning to transform those abilities into useful skills, where a skill can be considered as a set of sensory - motor associations. Using linear neural network models, it is proved that if skills are stored as distributed representations, then within- lifetime learning of part of a skill can induce automatic learning of the remaining parts of that skill. More importantly, it is shown that this " free- lunch'' learning ( FLL) is responsible for accelerated evolution of skills, when compared with networks which either 1) cannot benefit from FLL or 2) cannot learn. Specifically, it is shown that FLL accelerates the appearance of adaptive behaviour, both in its innate form and as FLL- induced behaviour, and that FLL can accelerate the rate at which learned behaviours become innate

An introduction to the constraints-led approach to learning in outdoor education

Participation in outdoor education is underpinned by a learner's ability to acquire skills in activities such as canoeing, bushwalking and skiing and consequently the outdoor leader is often required to facilitate skill acquisition and motor learning. As such, outdoor leaders might benefit from an appropriate and tested model on how the learner acquires skills in order to design appropriate learning contexts. This paper introduces an approach to skill acquisition based on ecological psychology and dynamical systems theory called the constraints-led approach to skills acquisition. We propose that this student-centred approach is an ideal perspective for the outdoor leader to design effective learning settings. Furthermore, this open style of facilitation is also congruent with learning models that focus on other concepts such as teamwork and leadership

Role of the dopamine system in motor skill learning : implications for neurodevelopmental disorders

Dopamine (DA), released by midbrain neurons, is critical for motor performance, motor skill learning, and corticostriatal synaptic plasticity. Dysregulation of DAergic signaling in corticostriatal circuitry has also been implicated in several highly heritable neurodevelopmental disorders, such as attention/deficit hyperactivity disorder (ADHD), which are often associated with deficits in fine motor skills. However, the cellular and molecular pathways mediating the effects of DA are still poorly understood. In the present thesis, we used a skilled reaching task to investigate potential DAergic mechanisms contributing to the acquisition and performance of fine motor skills (i.e., skilled reaching and grasping). To explore the influence of natural genetic variation in the DA system in motor skill learning, we took advantage of two inbred strains of mice (i.e., BALB/c and C57BL/6) that differ markedly in the number of midbrain DA neurons. We demonstrate significant variation in skilled reaching behavior in these two strains. Specifically, variations in the rate of motor learning correlated with divergent DA-related gene expression (e.g., DA D1 receptors and DARPP-32) in frontal cortex and striatum. These results implicate genetically driven variation in frontostriatal DAergic neurotransmission as a key contributor to individual differences in fine motor skill. To identify brain activity patterns associated with different phases of motor skill learning, we studied the induction of the plasticity-related gene Arc (also known as Arg3.1), and also investigated learning-induced changes in the DA system. In the early phase of motor skill learning, Arc mRNA was significantly induced in the corticostriatal circuitry, including the medial prefrontal cortex (mPFC), cingulate cortex, primary motor cortex, and striatum. In the late phase, however, a shift in the expression pattern of Arc was evident–with a significant decrease in Arc mRNA in most regions examined (except in the mPFC and striatum). There were also significant changes in the expression of DA D1 receptors and their intracellular target DARPP-32 in the striatum (but not cortical regions) during the early, but not late, phase of motor skill learning. Analysis of the phosphorylation state of dopamine- and cAMP-regulated phosphoprotein, Mr 32 kDa (DARPP-32) and its downstream target cAMP response element- binding protein (CREB) in the striatum indicated increased levels of phospho-Thr34-DARPP- 32 and phospho-Ser133-CREB during the early, but not late, phase of motor skill learning. These findings implicate the cAMP/PKA/DARPP-32 signaling pathway in the acquisition of novel motor skills, and also demonstrate a dynamic shift in the contribution of corticostriatal circuitry during different phases of motor skill learning. Finally, we explored whether spontaneously hypertensive rats (SHRs), the most commonly used genetic animal model of ADHD, is valid for investigating fine motor skill problems displayed by the majority of children with ADHD. Although SHRs could learn the skilled reaching task, their performance is significantly poorer than that of control rats in the most sensitive measure of skilled performance (i.e., success on the first attempt). However, gross motor coordination appears to be normal in SHRs, suggesting that the SHR strain displays specific deficits only in fine motor skills. Moreover, DARPP-32 was significantly higher expressed in corticostriatal circuitry of SHR compared to controls. Our results support the notion that the SHR strain is a useful animal model system to investigate potential molecular mechanisms underlying fine motor skill problems in ADHD. The present thesis gives evidence supporting the notion that normal genetic variation in the DAergic system might contribute substantially to variability in the acquisition of motor skills in humans. More specifically, the results suggest the involvement of the D1R/cAMP/DARPP- 32 signaling pathway in those neurodevelopmental disorders that are associated with fine motor skill deficits

Motor skill learning depends on protein synthesis in the dorsal striatum after training

Functional imaging studies in humans and electrophysiological data in animals suggest that corticostriatal circuits undergo plastic modifications during motor skill learning. In motor cortex and hippocampus circuit plasticity can be prevented by protein synthesis inhibition (PSI) which can interfere with certain forms learning. Here, the hypothesis was tested that inducing PSI in the dorsal striatum by bilateral intrastriatal injection of anisomycin (ANI) in rats interferes with learning a precision forelimb reaching task. Injecting ANI shortly after training on days 1 and 2 during 4days of daily practice (n=14) led to a significant impairment of motor skill learning as compared with vehicle-injected controls (n=15, P=0.033). ANI did not affect the animals' motivation as measured by intertrial latencies. Also, ANI did not affect reaching performance once learning was completed and performance reached a plateau. These findings demonstrate that PSI in the dorsal striatum after training impairs the acquisition of a novel motor skill. The results support the notion that plasticity in basal ganglia circuits, mediated by protein synthesis, contributes to motor skill learnin

The Effect of self-controlled practice on forearm passing, motivation, and affect in women’s volleyball players

Motor learning research has suggested that self-controlled practice (or “autonomy”) leads to more effective learning of motor tasks. Debate continues, however, as to why. Most motor behaviorists maintain the better learning is due to cognitive and information-processing factors. Recently, others have proposed the learning enhancement is due to such psychological factors as motivation and affect. The present study sought to measure motor skill learning, intrinsic motivation, and affect in self-controlled versus externally-controlled (yoked) practice conditions. Participants, 16 collegiate women’s volleyball student-athletes from two National Collegiate Athletic Association Division I programs, were paired by forearm passing skill level, and one of each pair was randomly placed in either the self-control or yoked group. The self-control participants were asked to design their own forearm passing drill during the practice phase of the experiment. The yoked participants followed the design established by the self-control participant to whom they were yoked. Each of the participants’ forearm passing accuracy was measured in a free ball passing drill consisting of a pre-test and practice phase on Day 1, and a post-test on Day 2. Their intrinsic motivation was measured using the Intrinsic Motivation Inventory (IMI), and their positive and negative affect was measured using the Positive and Negative Affect Scale – Expanded Edition (PANAS-X). The IMI and PANAS-X were administered in a baseline condition (after a team practice one week prior to participation in the study) at the end of Day 1, and the end of Day 2. Analysis of the data revealed no statistically significant differences between groups in either forearm passing, intrinsic motivation, or affect. Further research is needed to determine if intrinsic motivation and affect are partially responsible for the learning benefits of self-controlled practice

Sleep quality influences subsequent motor skill acquisition

While the influence of sleep on motor memory consolidation has been extensively investigated, its relation to initial skill acquisition is less well understood. The purpose of the present study was to investigate the influence of sleep quality and quantity on subsequent motor skill acquisition in young adults without sleep disorders. Fifty-five healthy adults (mean age = 23.8 years; 34 women) wore actigraph wristbands for 4 nights, which provided data on sleep patterns before the experiment, and then returned to the laboratory to engage in a motor sequence learning task (explicit 5-item finger sequence tapping task). Indicators of sleep quality and quantity were then regressed on a measure of motor skill acquisition (Gains Within Training, GWT). Wake After Sleep Onset (WASO; i.e., the total amount of time the participants spent awake after falling asleep) was significantly and negatively related to GWT. This effect was not because of general arousal level, which was measured immediately before the motor task. Conversely, there was no relationship between GWT and sleep duration or self-reported sleep quality. These results indicate that sleep quality, as assessed by WASO and objectively measured with actigraphy before the motor task, significantly impacts motor skill acquisition in young healthy adults without sleep disorders. (PsycINFO Database Record. (c) 2016 APA, all rights reserved).Accepted manuscrip

Vocal learning promotes patterned inhibitory connectivity.

Skill learning is instantiated by changes to functional connectivity within premotor circuits, but whether the specificity of learning depends on structured changes to inhibitory circuitry remains unclear. We used slice electrophysiology to measure connectivity changes associated with song learning in the avian analog of primary motor cortex (robust nucleus of the arcopallium, RA) in Bengalese Finches. Before song learning, fast-spiking interneurons (FSIs) densely innervated glutamatergic projection neurons (PNs) with apparently random connectivity. After learning, there was a profound reduction in the overall strength and number of inhibitory connections, but this was accompanied by a more than two-fold enrichment in reciprocal FSI-PN connections. Moreover, in singing birds, we found that pharmacological manipulations of RA's inhibitory circuitry drove large shifts in learned vocal features, such as pitch and amplitude, without grossly disrupting the song. Our results indicate that skill learning establishes nonrandom inhibitory connectivity, and implicates this patterning in encoding specific features of learned movements