Nectin-like molecules/SynCAMs are required for post-crossing commissural axon guidance.

The Necl/SynCAM subgroup of immunoglobulin superfamily cell adhesion molecules has been implicated in late stages of neural circuit formation. They were shown to be sufficient for synaptogenesis by their trans-synaptic interactions. Additionally, they are involved in myelination, both in the central and the peripheral nervous system, by mediating adhesion between glia cells and axons. Here, we show that Necls/SynCAMs are also required for early stages of neural circuit formation. We demonstrate a role for Necls/SynCAMs in post-crossing commissural axon guidance in the developing spinal cord in vivo. Necl3/SynCAM2, the family member that has not been characterized functionally so far, plays a crucial role in this process. It is expressed by floorplate cells and interacts with Necls/SynCAMs expressed by commissural axons to mediate a turning response in post-crossing commissural axons.

Neuroenhancement - perspectives of Swiss psychiatrists and general practitioners.

QUESTIONS UNDER STUDY: Although the ethical and health implications of neuroenhancement have been intensely discussed over the past years, little is known about the experiences and attitudes of physicians confronted with requests for neuroenhancing substances. The aim of this study was to explore general practitioners' and psychiatrists' familiarity with such requests and their willingness to prescribe these products. METHOD: A nation-wide cross-sectional survey among general practitioners and psychiatrists in Switzerland was conducted. A questionnaire was developed, pre-tested and sent out to a pre-defined sample of 1,600 Swiss practising physicians in the fields of psychiatry and general practice/internal medicine in the German-speaking and French-speaking part of Switzerland. RESULTS: A total of 393 questionnaires were returned (response rate: 24.7%). 80.2% of study participants were encountered requests for neuroenhancing products in their own practice, mostly not exceeding 1-2 times a year. A total of 41.1% were undecided when asked if they categorically against neuroenhancement, 49% would decide on a case-by-case basis, and 9.6% would decide according to patients' wishes. CONCLUSIONS: Swiss psychiatrists and general practitioners are confronted with requests for neuroenhancement, albeit not very frequently. Most participants embrace a pragmatic position towards neuroenhancement, although there is also a considerable degree of uncertainty about the appropriateness of a categorical refusal. A minority would follow a consumer model that leaves the decision about the use of neuroenhancers to the client, even though this conflicts with legal requirements regarding drug prescriptions.