Brain connectivity inversely scales with developmental temperature in Drosophila

Variability of synapse numbers and partners despite identical genes reveals the limits of genetic determinism. Here, we use developmental temperature as a non-genetic perturbation to study variability of brain wiring and behavior in Drosophila. Unexpectedly, slower development at lower temperatures increases axo-dendritic branching, synapse numbers, and non-canonical synaptic partnerships of various neurons, while maintaining robust ratios of canonical synapses. Using R7 photoreceptors as a model, we show that changing the relative availability of synaptic partners using a DIPγ mutant that ablates R7's preferred partner leads to temperature-dependent recruitment of non-canonical partners to reach normal synapse numbers. Hence, R7 synaptic specificity is not absolute but based on the relative availability of postsynaptic partners and presynaptic control of synapse numbers. Behaviorally, movement precision is temperature robust, while movement activity is optimized for the developmentally encountered temperature. These findings suggest genetically encoded relative and scalable synapse formation to develop functional, but not identical, brains and behaviors.

[Improving general practitioners guided dementia care: the pilot project start-modem in Rheinland-Pfalz, Germany]

BACKGROUND

The study examined the ability of trained General Practitioners (GPs) to carry out guideline based diagnostics and therapy of dementia. The article reports the GP-related findings.

METHODS

100 GPs took part in the prospective multi-centre study. 34 GPs started self-guided medical dementia care after attending a special training. The control group of 66 GPs referred patients suspected of dementia to specialist centres. Time of recruiting was 13 months. In case of dementia diagnosis patients and caregivers received professional psychosocial counselling.

RESULTS

Trained GPs reported improvements of sensitization and qualification through the project. The cross-linkage of GPs' medical dementia care and psychosocial counselling found a broad acceptance of the participants (GPs, patients, caregivers). 92 of the 156 included patients were diagnosed as dementia. Guideline conformity was violated in 65.4 % of all cases concerning structural imaging and in 30.1 % regarding laboratory tests. "Unspecified Dementia" was the most frequent ICD-10-diagnosis by GPs.

CONCLUSION

Despite the broad acceptance of the project a limited guideline-conformity as well as the diagnostic uncertainty suggests that the implemented training is only a first step towards GP guided dementia care. To extend GPs guided dementia care and to improve the quality of GPs dementia diagnostics and therapy sensitization of more GPs for active dementia care as well as supervised practical training will be necessary.