Faculty Bibliography

Identifying individuals with rare epilepsy syndromes in electronic data sources is difficult, in part because of missing codes in the International Classification of Diseases (ICD) system. Our objectives were the following: (1) to describe the representation of rare epilepsies in other medical vocabularies, to identify gaps; and (2) to compile synonyms and associated terms for rare epilepsies, to facilitate text and natural language processing tools for cohort identification and population-based surveillance. We describe the representation of 33 epilepsies in 3 vocabularies: Orphanet, SNOMED-CT, and UMLS-Metathesaurus. We compiled terms via 2 surveys, correspondence with parent advocates, and review of web resources and standard vocabularies. UMLS-Metathesaurus had entries for all 33 epilepsies, Orphanet 32, and SNOMED-CT 25. The vocabularies had redundancies and missing phenotypes. Emerging epilepsies (SCN2A-, SCN8A-, KCNQ2-, SLC13A5-, andSYNGAP-related epilepsies) were underrepresented. Survey and correspondence respondents included 160 providers, 375 caregivers, and 11 advocacy group leaders. Each epilepsy syndrome had a median of 15 (range 6-28) synonyms. Nineteen had associated terms, with a median of 4 (range 1-41). We conclude that medical vocabularies should fill gaps in representation of rare epilepsies to improve their value for epilepsy research. We encourage epilepsy researchers to use this resource to develop tools to identify individuals with rare epilepsies in electronic data sources.

In many species chemosensory stimuli function as important signals that influence reproductive status. Neurons synthesizing the peptide gonadotropin-releasing hormone (GnRH) are critical mediators of reproductive function via their regulation of the hypothalamic-pituitary-gonadal (HPG) axis, and they are thought to be responsive to chemosensory information. In the present study, we sought to elucidate the effects of female chemosensory stimuli on the HPG axis in sexually naive adult male Syrian hamsters. In Experiment 1, serial blood samples were collected from catheterized male hamsters following exposure to female pheromones in order to characterize the luteinizing hormone (LH) response to this chemosensory stimulus. In Experiment 2, brains and terminal blood samples were collected from animals 0, 60, and 120 min following pheromone exposure. GnRH mRNA was measured in brain tissue sections using in situ hybridization, and plasma concentrations of LH and testosterone were measured using radioimmunoassay. Data from Experiment 1 indicated that female pheromones elicited a rapid rise in plasma LH that peaked at 15 min and returned to baseline 45 min after exposure. In Experiment 2, testosterone was elevated in terminal blood samples obtained 60 min, but not 120 min, after exposure to pheromones. LH levels were unaffected at both of these time points. The chemosensory-induced increases in LH and testosterone release were not accompanied by subsequent changes in GnRH mRNA over the time course studied. These data suggest that while activation of the male HPG axis by female pheromones involves release of GnRH, it does not involve increases in GnRH mRNA 1-2 h after pheromonal stimulation as a mechanism for replenishment of released peptide.

The interaction between testosterone and pubertal development on aggression in the male Syrian hamster (Mesocricetus auratus) was examined in two experiments. First, gonad-intact prepubertal and adult male hamsters were tested for aggression using the resident-intruder paradigm with an age- and weight-matched intruder. Prepubertal males engaged in a greater number of attacks and had longer attack durations than adults. In the second experiment, prepubertal and adult males were castrated and treated with either a 0-, 2.5-, or 5-mg pellet of testosterone, and their aggression was assessed using the resident-intruder paradigm. Prepubertal males again showed shorter attack latencies and greater attack durations compared to adult males across all levels of testosterone. Testosterone treatment did not significantly affect these behaviors before or after pubertal development. We conclude that (a) pubertal development is associated with a decline in aggression in the male Syrian hamster, and (b) a developmental shift in behavioral sensitivity or responsiveness to testosterone does not underlie the pubertal decrease in aggression.