The neurohormones arginine-vasopressin (AVP) and oxytocin (OT) synthesised in supraoptic and paraventricular nuclei of neurohypophysis regulate lactation, systemic water homeostasis and nociception. Using transgenic rats expressing AVP and OT tagged with fluorescent proteins we demonstrate that both neurohormones are expressed in sensory neurones both in vitro, in primary cultures, and in situ, in the intact ganglia; this expression was further confirmed with immunocytochemistry. Both neurohormones were expressed in nociceptive neurones immunopositive to transient receptor potential vannilloid 1 (TRPV1) channel antibodies. The AVP and OT-expressing DRG neurones responded to AVP, OT, 50 mM K+ and capsaicin with [Ca2+]i transients; responses to AVP and OT were specifically blocked by the antagonists of V1 AVP and OT receptors. Probing the extracellular incubation saline with ELISA revealed AVP and OT secretion from isolated DRGs; this secretion was inhibited by tetanus toxin (TeNT) indicating the role for vesicular release. Expression of OT, but not AVP in DRG neurones significantly increased during lactation. Together, the results indicate novel physiological roles (possibly related to nociception and mood regulation) of AVP and OT in the sensory neurones.

• MeSH
• Dehydration metabolism   MeSH
• Exocytosis * MeSH
• Fluorescence MeSH
• Lactation * MeSH
• Sensory Receptor Cells metabolism   MeSH
• Nociception MeSH
• Oxytocin metabolism   MeSH
• Rats, Transgenic MeSH
• Receptors, Oxytocin metabolism   MeSH
• Receptors, Vasopressin metabolism   MeSH
• Ganglia, Spinal metabolism   MeSH
• Vasopressins metabolism   MeSH
• Pituitary Gland, Posterior metabolism   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Oxytocin MeSH
• Receptors, Oxytocin MeSH
• Receptors, Vasopressin MeSH
• Vasopressins MeSH

The magnocellular vasopressin (AVP) and oxytocin (OT) neurones exhibit specific electrophysiological behaviour, synthesise AVP and OT peptides and secrete them into the neurohypophysial system in response to various physiological stimulations. The activity of these neurones is regulated by the very same peptides released either somato-dendritically or when applied to supraoptic nucleus (SON) preparations in vitro. The AVP and OT, secreted somato-dendritically (i.e. in the SON proper) act through specific autoreceptors, induce distinct Ca(2+) signals and regulate cellular events. Here, we demonstrate that about 70% of freshly isolated individual SON neurones from the adult non-transgenic or transgenic rats bearing AVP (AVP-eGFP) or OT (OT-mRFP1) markers, produce distinct spontaneous [Ca(2+)]i oscillations. In the neurones identified (through specific fluorescence), about 80% of AVP neurones and about 60% of OT neurones exhibited these oscillations. Exposure to AVP triggered [Ca(2+)]i oscillations in silent AVP neurones, or modified the oscillatory pattern in spontaneously active cells. Hyper- and hypo-osmotic stimuli (325 or 275 mOsmol/l) respectively intensified or inhibited spontaneous [Ca(2+)]i dynamics. In rats dehydrated for 3 or 5days almost 90% of neurones displayed spontaneous [Ca(2+)]i oscillations. More than 80% of OT-mRFP1 neurones from 3 to 6-day-lactating rats were oscillatory vs. about 44% (OT-mRFP1 neurones) in virgins. Together, these results unveil for the first time that both AVP and OT neurones maintain, via Ca(2+) signals, their remarkable intrinsic in vivo physiological properties in an isolated condition.

• Keywords
• Ca(2+) oscillations, Dehydration, Electrical activity, Enhanced green fluorescence protein, Fluorescence spectrofluorimetry, Fura-2, Hyper-osmolarity, Hypo-osmolarity, Hypothalamus, Lactation, Magnocellular neurosecretory cells, Monomeric red fluorescence protein, Osmoregulation, Oxytocin, Skewness, Spationtemporal dynamics, Supraoptic nucleus, Transgenic rats, Vasopressin,
• MeSH
• Dehydration MeSH
• Neurons metabolism   MeSH
• Supraoptic Nucleus metabolism   MeSH
• Osmolar Concentration MeSH
• Oxytocin metabolism   MeSH
• Rats, Wistar MeSH
• Calcium metabolism   MeSH
• Calcium Signaling * MeSH
• Vasopressins metabolism   MeSH
• Green Fluorescent Proteins metabolism   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• enhanced green fluorescent protein MeSH Browser
• Oxytocin MeSH
• Calcium MeSH
• Vasopressins MeSH
• Green Fluorescent Proteins MeSH

Human embryonic stem cell-derived neural precursors (hESC NPs) are considered to be a promising tool for cell-based therapy in central nervous system injuries and neurodegenerative diseases. The Ca(2+) ion is an important intracellular messenger essential for the regulation of various cellular functions. We investigated the role and physiology of Ca(2+) signaling to characterize the functional properties of CCTL14 hESC NPs during long-term maintenance in culture (in vitro). We analyzed changes in cytoplasmic Ca(2+) concentration ([Ca(2+)]i) evoked by high K(+), adenosine-5'-triphosphate (ATP), glutamate, γ-aminobutyric acid (GABA), and caffeine in correlation with the expression of various neuronal markers in different passages (P6 through P10) during the course of hESC differentiation. We found that only differentiated NPs from P7 exhibited significant and specific [Ca(2+)]i responses to various stimuli. About 31% of neuronal-like P7 NPs exhibited spontaneous [Ca(2+)]i oscillations. Pharmacological and immunocytochemical assays revealed that P7 NPs express L- and P/Q-type Ca(2+) channels, P2X2, P2X3, P2X7, and P2Y purinoreceptors, glutamate receptors, and ryanodine (RyR1 and RyR3) receptors. The ATP- and glutamate-induced [Ca(2+)]i responses were concentration-dependent. Higher glutamate concentrations (over 100 μM) caused cell death. Responses to ATP were observed in the presence or in the absence of extracellular Ca(2+). These results emphasize the notion that with time in culture, these cells attain a transient period of operative Ca(2+) signaling that is predictive of their ability to act as stem elements.

• MeSH
• Biomarkers metabolism   MeSH
• Cell Differentiation drug effects   MeSH
• Time Factors MeSH
• Embryonic Stem Cells cytology   drug effects   metabolism   MeSH
• Glutamates pharmacology   MeSH
• Intracellular Space drug effects   metabolism   MeSH
• Microscopy, Confocal MeSH
• Humans MeSH
• Neural Stem Cells cytology   drug effects   metabolism   MeSH
• Cell Count MeSH
• Receptors, Purinergic metabolism   MeSH
• Calcium metabolism   MeSH
• Calcium Signaling * drug effects   MeSH
• Calcium Channels metabolism   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Biomarkers MeSH
• Glutamates MeSH
• Receptors, Purinergic MeSH
• Calcium MeSH
• Calcium Channels MeSH