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

Abstract

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. Accordingly, neurons have been shown to produce and release a large number of chemical mediators (neurotransmitters, neurohormones and neuromodulators) into the interstitial space, which include not only classic neurotransmitters, such as acetylcholine, amines (noradrenaline, serotonin) and amino acids (glutamate, GABA), but also gaseous (nitric oxide, carbon monoxide and hydrogen sulfide) and lipid-derived (endocannabinoids) mediators. This efferent response, initiated within the neuronal environment, recruits several peripheral effectors, such as hormones (glucocorticoids, angiotensin II, estrogen), which in turn modulate central nervous system responsiveness to systemic challenges. Therefore, in this review, we shall evaluate in an integrated manner the physiological control of body fluid homeostasis from the molecular aspects to the systemic and integrated responses.

Up‐regulation of hypothalamic arginine vasopressin by peripherally administered furosemide in transgenic rats expressing arginine vasopressin‐enhanced green fluorescent protein

“…The OVLT and SFO, which belong to circumventricular organs, lack a blood–brain barrier and contain cells that are sensitive to humoural signals, such as changes in plasma and cerebrospinal sodium concentrations, osmolality and angiotensin II levels . Humoural signals are then transmitted from the SFO and OVLT mainly via the MnPO to other structures in the CNS, including the PVN and SON, for control of AVP synthesis and secretion . In summary, we estimate that neuronal activation in the OVLT, MnPO and SFO may result from RAAS activation.…”

Role of AMPA and NMDA receptors on vasopressin and oxytocin secretion induced by hypertonic extracellular volume expansion

“…In the magnocellular neurones, the osmoreceptors and volume/baroreceptor signals are integrated via stimulatory and inhibitory mediators, such as angiotensin II, GABA, l ‐glutamate, taurine, nitric oxide and carbon monoxide . The participation of l ‐glutamate receptors in magnocellular neurone secretion was first demonstrated in vitro by Sladek et al., who showed that the osmotic release of AVP by SON neurones was inhibited by the l ‐glutamate receptor blockade.…”

Offspring’s hydromineral adaptive responses to maternal undernutrition during lactation

“…56 We studied a specific structure of the central nervous system responsible for the reception, analysis and integration of information and the consequent induction of appropriate responses, the SFO, and areas involved in the central integration of the visceral and somatic sensory inputs, such as the PVN and SON of the hypothalamus. 57 We found that Fos immunoreactivity in the SON, PVN and SFO was always higher in the ISO-treated offspring: both FR, food restricted group. Renal histological analysis.…”