RESUMO
Background: The suprachiasmatic nucleus (SCN) within the hypothalamus is a key brain structure required to relay light information to the body and synchronize cell and tissue level rhythms and hormone release. Specific subpopulations of SCN neurons, defined by their peptide expression, regulate defined SCN output. Here we focus on the vasoactive intestinal peptide (VIP) expressing neurons of the SCN. SCN VIP neurons are known to regulate circadian rhythms and reproductive function. Methods: To specifically study SCN VIP neurons, we generated a novel knock out mouse line by conditionally deleting the SCN enriched transcription factor, Ventral Anterior Homeobox 1 (Vax1), in VIP neurons (Vax1Vip; Vax1fl/fl:VipCre). Results: We found that Vax1Vip females presented with lengthened estrous cycles, reduced circulating estrogen, and increased depressive-like behavior. Further, Vax1Vip males and females presented with a shortened circadian period in locomotor activity and ex vivo SCN circadian period. On a molecular level, the shortening of the SCN period was driven, at least partially, by a direct regulatory role of VAX1 on the circadian clock genes Bmal1 and Per2. Interestingly, Vax1Vip females presented with increased expression of arginine vasopressin (Avp) in the paraventricular nucleus, which resulted in increased circulating corticosterone. SCN VIP and AVP neurons regulate the reproductive gonadotropin-releasing hormone (GnRH) and kisspeptin neurons. To determine how the reproductive neuroendocrine network was impacted in Vax1Vip mice, we assessed GnRH sensitivity to a kisspeptin challenge in vivo. We found that GnRH neurons in Vax1Vip females, but not males, had an increased sensitivity to kisspeptin, leading to increased luteinizing hormone release. Interestingly, Vax1Vip males showed a small, but significant increase in total sperm and a modest delay in pubertal onset. Both male and female Vax1Vip mice were fertile and generated litters comparable in size and frequency to controls. Conclusion: Together, these data identify VAX1 in SCN VIP neurons as a neurological overlap between circadian timekeeping, female reproduction, and depressive-like symptoms in mice, and provide novel insight into the role of SCN VIP neurons.
Assuntos
Neuropeptídeos , Fatores de Transcrição , Masculino , Feminino , Animais , Camundongos , Peptídeo Intestinal Vasoativo , Kisspeptinas/genética , Sêmen , Núcleo Supraquiasmático , Reprodução , Neurônios , Ritmo Circadiano , Hormônio Liberador de Gonadotropina , Proteínas de HomeodomínioRESUMO
El síndrome de Guillain-Barré (SGB) o poli-rradiculoneuritis aguda es una enfermedad autoinmune, desencadenada por una infec-ción viral o bacteriana, su incidencia es de 1.7/100000, únicamente el 3% puede recaer en los años subsiguientes. Es una patología poco frecuente y menos frecuente aún son los casos recurrentes, por lo que realizamos una revisión de su epidemiología, cuadro clínico, criterios diagnósticos y su manejo. Se trata de un paciente masculino de 9 años de edad, que el 13 de octubre de 2008 al primer año de edad fue ingresado durante 1 mes al Instituto Hondureño de Seguridad Social (IHSS) con cuadro de parálisis flácida ascendente progresiva (Síndrome de Guillain Barré), recibió manejo con inmunoglobulina cuya dosis y otros datos sobre su tratamiento, exámenes o estudios realizados se descono-cen. La recuperación completa se dio aproxi-madamente a los 6 meses posteriores al inicio de los síntomas. Sin embargo reingresa el 12 de noviembre de 2014 en IHSS con diagnóstico de Parálisis Flácida ascendente recurrente (segundo episodio), sin recupera-ción completa ya que presentó secuelas en miembros inferiores. Se le realizó Electromio-grafía con datos compatibles con polirradicu-lopatía motora desmielinizante simétrica. En marzo de este año (2017) se presenta con igual sintomatología por lo que se ingresa como síndrome de Guillain barré recurrente (tercer episodio)...(AU)
Assuntos
Humanos , Masculino , Criança , Polirradiculoneuropatia/diagnóstico , Síndrome de Guillain-Barré/diagnóstico , Campylobacter jejuniRESUMO
The aim of this work was to study effect of the dry matter intake level on the concentrations of glucose, insulin, urea, estrogen and progesterone in the blood and the level of IGF-I in the follicular liquid of heifers. Twenty seven crossbred heifers were used, in three treatments: 1.2, 1.6 and 2.6 percent of the live weight of dry matter intake (DMI) daily. The sanguine concentrations of glucose and estrogen were higher in the animals with 1.6 percent of DMI and the insulin levels were higher in the animals with 2.6 percent of DMI. There was an increase in the sanguine levels of urea with the increase of the DMI. There was no effect of the DMI on the progesterone levels in the sanguine plasma collected from the jugular. The progesterone levels in caudal vena were higher in the animals with 2.6 percent of DMI. There was no effect of the DMI on the follicular levels of IGF-I.
O objetivo deste trabalho foi estudar o efeito do nível de ingestão de matéria seca (IMS/ por cento do PV) sobre as concentrações sanguíneas de glicose, insulina, urea, estrógeno e progesterona e o nível de IGF-I no líquido folicular de novilhas. Vinte e sete novilhas cruzadas foram utilizadas, distribuídas em três tratamentos: 1,2 por cento; 1,6 por cento e 2,6 por cento do peso vivo de ingestão de matéria seca por dia. As concentrações no plasma da veia jugular de glicose e estrógeno foram maiores nos animais com 1,6 por cento de IMS e os níveis de insulina foram maiores nos animais com 2,6 por cento de IMS. Houve um aumento dos níveis plasmáticos de uréia com aumento dos níveis de IMS. Não houve efeito da IMS sobre os níveis de progesterona no plasma sangüíneo coletado da jugular. No plasma sangüíneo coletado da veia cada caudal, os níveis de progesterona foram maiores (P<0,05) nos animais com 2,6 por cento de IMS. Não houve efeito da IMS sobre os níveis foliculares de IGF-I.