Short-Term High-Fat Diet Increases Leptin Activation of CART Neurons and Advances Puberty in Female Mice.

Leptin is a permissive factor for puberty initiation, participating as a metabolic cue in the activation of the kisspeptin (Kiss1)-gonadotropin-releasing hormone neuronal circuitry; however, it has no direct effect on Kiss1 neurons. Leptin acts on hypothalamic cocaine- and amphetamine-regulated transcript (CART) neurons, participating in the regulation of energy homeostasis. We investigated the influence of a short-term high-fat diet (HFD) on the effect of leptin on puberty timing.

Temporal dissociation between sodium depletion and sodium appetite appearance: Involvement of inhibitory and stimulatory signals.

Our aim was to analyze the participation of inhibitory and stimulatory signals in the temporal dissociation between sodium depletion (SD) induced by peritoneal dialysis (PD) and the appearance of sodium appetite (SA), particularly 2h after PD, when the rats are hypovolemic/natremic but SA is not evident. We investigated the effects of bilateral injections of the serotonin (5-HT) receptor antagonist, methysergide, into the lateral parabrachial nucleus (LPBN) on hypertonic NaCl and water intake 2h vs. 24h after PD.

Mapping and signaling of neural pathways involved in the regulation of hydromineral homeostasis.

Several forebrain and brainstem neurochemical circuitries interact with peripheral neural and humoral signals to collaboratively maintain both the volume and osmolality of extracellular fluids. Although much progress has been made over the past decades in the understanding of complex mechanisms underlying neuroendocrine control of hydromineral homeostasis, several issues still remain to be clarified. The use of techniques such as molecular biology, neuronal tracing, electrophysiology, immunohistochemistry, and microinfusions has significantly improved our ability to identify neuronal phenotypes and their signals, including those related to neuron-glia interactions.

Oxytocin in the central amygdaloid nucleus modulates the neuroendocrine responses induced by hypertonic volume expansion in the rat.

The present study investigated the involvement of the oxytocinergic neurones that project into the central amygdala (CeA) in the control of electrolyte excretion and hormone secretion in unanaesthetised rats subjected to acute hypertonic blood volume expansion (BVE; 0.3 M NaCl, 2 ml/100 g of body weight over 1 min). Oxytocin and vasopressin mRNA expression in the paraventricular (Pa) and supraoptic nucleus (SON) of the hypothalamus were also determined using the real time-polymerase chain reaction and in situ hybridisation.