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.

• Klíčová slova
• 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
• dehydratace MeSH
• neurony metabolismus   MeSH
• nucleus supraopticus metabolismus   MeSH
• osmolární koncentrace MeSH
• oxytocin metabolismus   MeSH
• potkani Wistar MeSH
• vápník metabolismus   MeSH
• vápníková signalizace * MeSH
• vasopresiny metabolismus   MeSH
• zelené fluorescenční proteiny metabolismus   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• enhanced green fluorescent protein MeSH Prohlížeč
• oxytocin MeSH
• vápník MeSH
• vasopresiny MeSH
• zelené fluorescenční proteiny MeSH