Differentiation and on axon-guidance chip culture of human pluripotent stem cell-derived peripheral cholinergic neurons for airway neurobiology studies.

Airway cholinergic nerves play a key role in airway physiology and disease. In asthma and other diseases of the respiratory tract, airway cholinergic neurons undergo plasticity and contribute to airway hyperresponsiveness and mucus secretion. We currently lack human in vitro models for airway cholinergic neurons. Here, we aimed to develop a human in vitro model for peripheral cholinergic neurons using human pluripotent stem cell (hPSC) technology. hPSCs were differentiated towards vagal neural crest precursors and subsequently directed towards functional airway cholinergic neurons using the neurotrophin brain-derived neurotrophic factor (BDNF). Cholinergic neurons were characterized by ChAT and VAChT expression, and responded to chemical stimulation with changes in Ca2+ mobilization. To culture these cells, allowing axonal separation from the neuronal cell bodies, a two-compartment PDMS microfluidic chip was subsequently fabricated. The two compartments were connected via microchannels to enable axonal outgrowth. On-chip cell culture did not compromise phenotypical characteristics of the cells compared to standard culture plates. When the hPSC-derived peripheral cholinergic neurons were cultured in the chip, axonal outgrowth was visible, while the somal bodies of the neurons were confined to their compartment. Neurons formed contacts with airway smooth muscle cells cultured in the axonal compartment. The microfluidic chip developed in this study represents a human in vitro platform to model neuro-effector interactions in the airways that may be used for mechanistic studies into neuroplasticity in asthma and other lung diseases.

[Upward trend in the use of psychostimulants by adults]. / Stijgende lijn in het gebruik van psychostimulantia door volwassenen.

OBJECTIVE: To gain insight into the trends in the use of psychostimulants among adults. DESIGN: Retrospective database study. METHODS: We selected data on adults (≥ 18 years) who had had a minimum of 2 prescriptions for a psychostimulant drug within 1 year from IADB.nl, a Netherlands database of filled prescriptions (59 public pharmacies, approximately 600,000 patients). We calculated both the number of new users and the total number of users of psychostimulants per year in the period 2004-2014. We also assessed which agent was the most commonly prescribed psychostimulant drug and who had initiated treatment. RESULTS: The number of adults who were prescribed psychostimulants (methylphenidate, dexamphetamine and amphetamine) increased from 1.5 per 1000 adults in 2004 to 7.8 per 1000 adults in 2014. Users were mainly male (63.0%) and methylphenidate was the most frequently prescribed agent (85.7%). The number of new users of these agents increased from 0.5 to 1.5 per 1000 adults, and the greatest increase was observed among young adults (< 30 years). The increase in new users seems to have stabilized since 2012. Around 40% of new treatments were initiated by the GP. CONCLUSION: The large increase in the number of adults who are prescribed psychostimulants seems mainly to be the result of an increase in the number of new users, especially among young adults. As psychostimulants are only approved for the treatment of ADHD in children from 6 years of age and in adolescents, short- and long-term effects and side effects of these drugs need to be better assessed in the adult population.