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To conclusively test for a specific association between the biological marker 25-hydroxy-vitamin D3, a transcriptionally active hormone produced in human skin and liver, and the prevalence and severity of Parkinson disease (PD).

Single-neuronal studies remain the gold standard for studying brain function. Here we describe a protocol for studying task-related single-neuronal activity in human subjects during neurosurgical procedures involving microelectrode recordings. This protocol has two phases: a preoperative phase and an intraoperative phase. During the preoperative phase, we discuss informed consent, equipment setup and behavioral testing. During the intraoperative phase, we discuss the procedure for microelectrode recordings. Because patients are often awake during these procedures, this protocol can be performed in conjunction with behavioral tasks for studying a variety of cognitive functions. We describe the protocol in detail and provide two examples of expected results. In addition, we discuss the potential difficulties and pitfalls related to intraoperative studies. This protocol takes ∼1.5 h to complete.

Brain diseases and their treatment may help or hurt creativity in ways that shape quality of life. Increased creative drive is associated with bipolar disorder, depression, psychosis, temporal lobe epilepsy, frontotemporal dementia, Parkinson disease treatments, and autism. Creativity depends on goal-driven approach motivation from midbrain dopaminergic systems. Fear-driven avoidance motivation is of less aid to creativity. When serotonin and norepinephrine lower motivation and flexible behaviour, they can inhibit creativity. Hemispheric lateralization and frontotemporal connections must interact to create new ideas and conceptual schemes. The right brain and temporal lobe contribute skill in novelty detection, while the left brain and frontal lobe foster approach motivation and more easily generate new patterns of action from the novel perceptions. Genes and phenotypes that increase plasticity and creativity in tolerant environments with relaxed selection pressure may confer risk in rigorous environments. Few papers substantively address this important but fraught topic. Antidepressants (ADs) that inhibit fear-driven motivation, such as selective serotonin reuptake inhibitors, sometimes inhibit goal-oriented motivation as well. ADs that boost goal-directed motivation, such as bupropion, may remediate this effect. Benzodiazepines and alcohol may be counterproductive. Although dopaminergic agonists sometimes stimulate creativity, their doing so may inappropriately disinhibit behaviour. Dopamine antagonists may suppress creative motivation; lithium and anticonvulsant mood stabilizers may do so less. Physical exercise and REM sleep may help creativity. Art therapy and psychotherapy are not well studied. Preserving creative motivation can help creativity and other aspects of well-being in all patients, not just artists or researchers.

Although previous studies of focal hand dystonia have detected cortical sensorimotor abnormalities, little is known about the role of the basal ganglia in this disorder. We report here that when focal hand dystonic patients performed finger-tapping tasks, functional magnetic resonance imaging showed persisting elevations of basal ganglia activity after the tasks ended. We posit that inhibitory control of the basal ganglia may be faulty in focal hand dystonia, and that the increases we observe in “resting” activity may mask basal ganglia abnormalities in standard imaging contrast analyses.

Although previous studies of focal hand dystonia have detected cortical sensorimotor abnormalities, little is known about the role of the basal ganglia in this disorder. We report here that when focal hand dystonic patients performed finger‐tapping tasks, functional magnetic resonance imaging showed persisting elevations of basal ganglia activity after the tasks ended. We posit that inhibitory control of the basal ganglia may be faulty in focal hand dystonia, and that the increases we observe in “resting” activity may mask basal ganglia abnormalities in standard imaging contrast analyses.