Narcolepsy and odor: preliminary report / Narcolepsia y olor: resultados preliminares

Objetivo: El propósito de este estudio es probar la hipótesis de un olor corporal característico en narcolepticos como indicador de diagnóstico. Métodos: Se testan muestras de sudor de 12 narcolepticos y 22 controles sanos de forma independiente por dos perros entrenados y su detección, positiva o negativa, se compara con el diagnostico ‘‘gold standard’’ de narcolepsia. Ni adiestrador ni perros conocían el tipo de muestra seleccionada o su emplazamiento en el dispositivo de búsqueda. 12 pacientes con narcolepsia, de ambos sexos y distintas edades, reclutados entre abril de 2011 y junio de 2012, y diagnosticados de acuerdo a criterios estándar, a través de su historia clínica y polisomnografía nocturna seguida de test de latencia múltiple del sue˜no, conforman el grupo de pacientes. El grupo control está formado por 22 voluntarios sanos, de ambos sexos y distintas edades, sin trastorno del sue˜no. Las muestras de sudor, tanto de pacientes como de controles, se recogieron siguiendo el mismo protocolo para evitar contaminación y fueron testadas de forma independiente por dos perros entrenados. Resultados: 11 narcolepticos son detectados positivamente por los perros frente a solo 3 controles sanos. Conclusión: Parece que los pacientes con narcolepsia tienen un olor corporal típico que perros entrenados pueden detector. El desarrollo de un test de olfato para el diagnostico de narcolepsia abre nuevas áreas de investigación (AU)

Objectives. This study has been carried out to test the clinical hypothesis of personal smell as a hint to the diagnosis of narcoleptic patients. Methods. Sweat samples from narcoleptic and healthy controls were tested independently by two trained dogs and their positive or negative detection compared to the gold standard diagnosis for narcolepsy. Neither trainer nor dog knew the source of the sample selected or its placement in the search device. Twelve narcoleptic patients, both sexes and various ages, recruited from April 2011 to June 2012 and diagnosed according to standard criteria, through their clinical records and nocturnal polysomnography plus multiple sleep latency test, made up the patient group. The control group was made up of 22 healthy volunteer without sleep disorders, both sexes and various ages. Sweat samples from both patients and controls were collected following the same protocol to avoid contamination, and tested independently by two trained dogs. Results. Eleven narcoleptic were detected positive by the dogs while only three controls. Conclusion. It seems that narcoleptic patients have a distinct typical odor that trained dogs can detect. The development of olfactory test could be a useful method in the screening of narcolepsy while opens a new research area (AU)

Photoperiod mediated changes in olfactory bulb neurogenesis and olfactory behavior in male white-footed mice (Peromyscus leucopus).

Brain plasticity, in relation to new adult mammalian neurons generated in the subgranular zone of the hippocampus, has been well described. However, the functional outcome of new adult olfactory neurons born in the subventricular zone of the lateral ventricles is not clearly defined, as manipulating neurogenesis through various methods has given inconsistent and conflicting results in lab mice. Several small rodent species, including Peromyscus leucopus, display seasonal (photoperiodic) brain plasticity in brain volume, hippocampal function, and hippocampus-dependent behaviors; plasticity in the olfactory system of photoperiodic rodents remains largely uninvestigated. We exposed adult male P. leucopus to long day lengths (LD) and short day lengths (SD) for 10 to 15 weeks and then examined olfactory bulb cell proliferation and survival using the thymidine analog BrdU, olfactory bulb granule cell morphology using Golgi-Cox staining, and behavioral investigation of same-sex conspecific urine. SD mice did not differ from LD counterparts in granular cell morphology of the dendrites or in dendritic spine density. Although there were no differences due to photoperiod in habituation to water odor, SD mice rapidly habituated to male urine, whereas LD mice did not. In addition, short day induced changes in olfactory behavior were associated with increased neurogenesis in the caudal plexiform and granule cell layers of the olfactory bulb, an area known to preferentially respond to water-soluble odorants. Taken together, these data demonstrate that photoperiod, without altering olfactory bulb neuronal morphology, alters olfactory bulb neurogenesis and olfactory behavior in Peromyscus leucopus.