A Competency-Guided Approach to Optimizing a Physician-Scientist Curriculum.

Physician-scientists are uniquely positioned to achieve significant biomedical advances to improve the human condition. Their clinical and scientific training allows them to bridge fields and contribute to cutting-edge, clinically relevant research. The need for a highly skilled physician-scientist workforce has never been more acute. We propose a competency-guided program design (CGPD) framework that focuses on core skills to enhance the physician-scientist training curriculum. In partnership with clinical and graduate curricula, the CGPD framework can be employed as a tool to meaningfully integrate physician-scientist training, address barriers to attract and sustain the physician-scientist workforce, and avoid overprogramming that detracts from a solid foundation of clinical and graduate research training.

Excitatory drive onto dopaminergic neurons in the rostral linear nucleus is enhanced by norepinephrine in an α1 adrenergic receptor-dependent manner.

Dopaminergic innervation of the extended amygdala regulates anxiety-like behavior and stress responsivity. A portion of this dopamine input arises from dopamine neurons located in the ventral lateral periaqueductal gray (vlPAG) and rostral (RLi) and caudal linear nuclei of the raphe (CLi). These neurons receive substantial norepinephrine input, which may prime them for involvement in stress responses. Using a mouse line that expresses eGFP under control of the tyrosine hydroxylase promoter, we explored the physiology and responsiveness to norepinephrine of these neurons. We find that RLi dopamine neurons differ from VTA dopamine neurons with respect to membrane resistance, capacitance and the hyperpolarization-activated current, Ih. Further, we found that norepinephrine increased the frequency of spontaneous excitatory postsynaptic currents (sEPSCs) on RLi dopamine neurons. This effect was mediated through the α1 adrenergic receptor (AR), as the actions of norepinephrine were mimicked by the α1-AR agonist methoxamine and blocked by the α1-AR antagonist prazosin. This action of norepinephrine on sEPSCs was transient, as it did not persist in the presence of prazosin. Methoxamine also increased the frequency of miniature EPSCs, indicating that the α1-AR action on glutamatergic transmission likely has a presynaptic mechanism. There was also a modest decrease in sEPSC frequency with the application of the α2-AR agonist UK-14,304. These studies illustrate a potential mechanism through which norepinephrine could recruit the activity of this population of dopaminergic neurons.