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ZusammenfassungStudierende der Humanmedizin müssen sich im Rahmen ihrer universitären Ausbildung ein umfangreiches Wissen zunächst aus den Grundlagenwissenschaften und später aus den verschiedensten medizinischen Fachgebieten aneignen. Für Vertiefungen, insbesondere in kleinere, aber dennoch hochinteressante Fachbereiche − etwa der Nuklearmedizin – bleibt dabei oft wenig Zeit. Eine Option, Vertiefungen über den in Seminaren und Vorlesungen vermittelten, vorwiegend klinisch orientierten Stoff zu ermöglichen, bieten Wahlfächer. Die Klinik und Poliklinik für Nuklearmedizin des Universitätsklinikums Leipzig hat in diesem Jahr ein zusätzliches Wahlfach etabliert („Nuklearmedizin universal“), welches v. a. auf die Vermittlung des interdisziplinären Zusammenwirkens von Ärzten, Radiochemikern, Medizinphysikern/-technikern und Medizinisch-technischen Assistenten innerhalb der Nuklearmedizin abzielt. Das entsprechende Curriculum sowie die ersten Erfahrungen werden beschrieben und reflektiert.

Objectives: The neurobiological mechanisms linking obesity to emotional distress remain largely undiscovered.Methods: In this pilot study, we combined positron emission tomography, using the norepinephrine transporter (NET) tracer [11C]-O-methylreboxetine, with functional connectivity magnetic resonance imaging, the Beck depression inventory (BDI), and the impact of weight on quality of life–Lite questionnaire (IWQOL–Lite), to investigate the role of norepinephrine in the severity of depression (BDI), as well as in the loss of emotional well-being with body weight (IWQOL–Lite).Results: In a small group of lean-to-morbidly obese individuals (n=20), we show that an increased body mass index (BMI) is related to a lowered NET availability within the hypothalamus, known as the brain’s homeostatic control site. The hypothalamus displayed a strengthened connectivity in relation to the individual hypothalamic NET availability to the anterior insula/frontal operculum, as well as the medial orbitofrontal cortex, assumed to host the primary and secondary gustatory cortex, respectively (n=19). The resting-state activity in these two regions was correlated positively to the BMI and IWQOL–Lite scores, but not to the BDI, suggesting that the higher the resting-state activity in these regions, and hence the higher the BMI, the stronger the negative impact of the body weight on the individual’s emotional well-being was.Conclusions: This pilot study suggests that the loss in emotional well-being with weight is embedded within the central norepinephrine network.

The neurobiological mechanisms linking obesity to emotional distress related to weight remain largely unknown.Here we combined positron emission tomography, using the serotonin transporter (5-HTT) radiotracer [(11)C]-3-amino-4-(2-dimethylaminomethylphenylsulfanyl)-benzonitrile, with functional connectivity magnetic resonance imaging, the Beck Depression Inventory (BDI-II) and the Impact of Weight on Quality of Life-Lite questionnaire (IWQOL-Lite) to investigate the role of central serotonin in the severity of depression (BDI-II), as well as in the loss of emotional well-being with body weight (IWQOL-Lite).In a group of lean to morbidly obese individuals (n=28), we found sex differences in the 5-HTT availability-related connectivity of the hypothalamus. Males (n=11) presented a strengthened connectivity to the lateral orbitofrontal cortex, whereas in females (n=17) we found strengethened projections to the ventral striatum. Both regions are known as reward regions involved in mediating the emotional response to food. Their resting-state activity correlated positively to the body mass index (BMI) and IWQOL-Lite scores, suggesting that each region in both sexes also underpins a diminished sense of emotional well-being with body weight. Contrarily to males, we found that in females also the BDI-II positively correlated with the BMI and by trend with the activity in ventral striatum, suggesting that in females an increased body weight may convey to other mood dimensions than those weight-related ones included in the IWQOL-Lite.This study suggests sex differences in serotonin-hypothalamic connections to brain regions of the reward circuitry underpinning a diminished sense of emotional well-being with an increasing body weight.

Introduction Degeneration of dopaminergic neurons in the substantia nigra projecting to the striatum is responsible for the motor symptoms in Parkinson's disease (PD). Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a well-established procedure to alleviate these symptoms in advanced PD. Yet the mechanism of action, especially the effects of DBS on striatal dopamine transporter (DAT) availability, remains largely unknown. Objectives The aim of our study was therefore to evaluate whether (1) DAT availability changes within one year after DBS and whether (2) the clinical outcome is predictable by DAT availability before surgical procedure (pre-op). Patients and methods Twenty-nine PD patients (age: 62.3±8.7y; duration of illness: 12.9±4.8y; L-dopa equivalent dose LED: pre 943±465mg, post 313±206mg; motor score UPDRS III pre ON (LED): 25.8±12.0, pre OFF: 42.0±14.6, post ON (LED+DBS): 15.9±9.1, post OFF: 40.1±14.0) underwent [ 123 I] FP-CIT SPECT prior and one year after STN-DBS. DAT availability (specific-to-unspecific binding ratio SBR) was assessed by volume of interest- (VOI; PMOD 3.4; caudate nucleus; putamen) and a voxel-based analysis. SBR were correlated with the severity of disease (UPDRS III). Results (1) UPDRS III improved significantly one year after STN-DBS (ON-state p =0.006) while in parallel LED was reduced ( p p r =−0.01; p =0.972; ON putamen ON: r =−0.31; p =0.898). Conclusion In accordance with own previous findings (Hesse et al., 2008), DAT availability is stable one-year after STN-DBS. However, DAT availability pre-op did not predict the clinical outcome after this follow-up period under STN-DBS. Whether a subtype-specific pattern of pre-op DAT availability helps to distinguish between responder and non-responder has to be evaluated in larger study cohorts. At this time the meaning of DAT alteration in the ventral striatum is unclear; a correlation to neuropsychiatric symptoms is assumed but this hypothesis needs further exploration as well.