Behavioral and physiological traits of migrant and resident white-crowned sparrows: a common garden approach.

To accommodate a migratory life history, migrants express a greater number of physiological and behavioral stages per annum than residents and are thus considered to have higher finite state diversity (FSD). To investigate the physiological mechanisms and constraints associated with migration, direct comparison of two subspecies of white-crowned sparrow - migrant, Zonotrichia leucophrys gambelii, and resident, Z. l. nuttalli - were made under common garden conditions of photoperiod and housing, as birds progressed from winter through the vernal life history stages. We tested the hypothesis that migrants (higher FSD) respond differently than residents (lower FSD) to the initial predictive cue, photoperiod, to initiate and integrate the progression of vernal stages of prenuptial molt, migration and development of breeding. If differences in vernal phenology were noted, then the basis for the distinctions was considered genetic. Results indicate that (1) residents had a lower threshold to vernal photoperiod with elevations of plasma androgen, growth and development of reproductive structures preceding those of migrants; (2) only migrants displayed prenuptial molt, preparations for migration and migratory restlessness; and (3) neither baseline nor stress-induced plasma corticosterone differed across subspecies, suggesting energetic demands of the common garden were insufficient to induce a differential adrenocortical response in either subspecies, highlighting the impact of environmental conditions on corticosterone secretion. Thus, in a common garden experiment, Z. l. gambelii responds differently to the initial predictive cue, photoperiod, to initiate and execute the vernal stages of molt, migration and development of breeding in comparison to the shared stage of breeding with Z. l. nuttalli, confirming a genetic basis for the subspecies differences.

Morvan Fibrillary Chorea Associated with Monoclonal B Cell Lymphocytosis.

BACKGROUND Morvan fibrillary chorea (Morvan syndrome) is a rare disorder marked by a collection of neurological symptoms such as myokymia, peripheral nerve excitability, neuromyotonia, autonomic instability, memory impairment, and delirium. Morvan syndrome is suspected to occur through antibodies directed against voltage gated potassium channels (VGKC), and has been linked with several autoimmune conditions and hematologic malignancies. We present a case of Morvan syndrome in association with monoclonal B cell lymphocytosis. Upon our literature review, we believe this to be the first documented case of Morvan syndrome associated with monoclonal B cell lymphocytosis. CASE REPORT The present case report describes a 75-year-old man with Morvan's syndrome. The patient had a diverse neurologic presentation with encephalopathy, progressive neuropathic pain, muscle fasciculations, myokymia, sensory deficits, and Bell's palsy. Ultimately, a paraneoplastic antibody panel revealed a positive titer of contactin-associated protein-like IgG (CASPR) and VGKC antibody. Flow cytometry showed a small population of abnormal lambda-restricted B cells. Given his symptoms, positive CASPR antibody, and flow cytometry findings, he was diagnosed with Morvan syndrome associated with monoclonal B cell lymphocytosis. He was treated with IV methylprednisolone and IVIG, with immediate improvement in neurologic symptoms. CONCLUSIONS Morvan syndrome presents with a spectrum of neurologic symptoms and is associated with autoantibodies against VGKC through anti-CASPR2 antibodies. Classically, Morvan syndrome presents as a paraneoplastic disease secondary to thymomas. Our case demonstrates that there is an association between B cell lymphoproliferative disorders and Morvan syndrome.

Comparison of the Phenotypic Flexibility of Muscle and Body Condition of Migrant and Resident White-Crowned Sparrows.

AbstractSeasonally breeding birds express variations of traits (phenotypic flexibility) throughout their life history stages that represent adaptations to environmental conditions. Changes of body condition during migration have been well studied, whereas alterations of skeletal and cardiac muscles, body mass, and fat scores have yet to be characterized throughout the spring or fall migratory stages. Additionally, we examined flexible patterns of muscle, body mass, and fat score in migrant white-crowned sparrows (Zonotrichia leucophrys gambelii) in comparison with those in a resident subspecies (Zonotrichia leucophrys nuttalli) during the stages they share to evaluate the influence of different life histories. Migrants showed hypertrophy of the pectoralis muscle fiber area on the wintering grounds in late prealternate molt, yet increased pectoralis muscle mass was not detected until birds readied for spring departure. While pectoralis profile and fat scores enlarged at predeparture in spring and fall, pectoralis, cardiac, and body masses were greater only in spring stages, suggesting seasonal differences for migratory preparation. Gastrocnemius mass showed little change throughout all stages, whereas gastrocnemius fiber area declined steadily but rebounded in fall on the wintering grounds, where migrants become more sedentary. In general, residents are heavier birds with larger leg structures, while migrants sport longer wings and greater heart mass. Phenotypic flexibility was most prominent among residents with peaks of pectoralis, gastrocnemius, and body masses during the winter stage, when local weather is most severe. Thus, the subspecies express specific patterns of phenotypic flexibility with peaks coinciding with the stages of heightened energy demands: the winter stage for residents and the spring stages for migrants.