Evidence for a Hypothalamic Oxytocin-Sensitive Pattern-Generating Network Governing Oxytocin NeuronsIn Vitro

Autor: Michèle Allard, Dominique A. Poulain, Vitiello Sergio, Jean-Marc Israel, B. Dupouy, Stéphane H. R. Oliet, Dionysia T. Theodosis, Pascal Jourdain
Přispěvatelé: Neurobiologie morphofonctionnelle, Université Bordeaux Segalen - Bordeaux 2-Institut François Magendie-IFR8-Institut National de la Santé et de la Recherche Médicale (INSERM), Oliet, Stéphane
Rok vydání: 1998
Předmět:
MESH: Neurons
Ornipressin
Kainate receptor
Oxytocin
MESH: Synapses
MESH: Linear Models
MESH: Neuro
chemistry.chemical_compound
Vasotocin
0302 clinical medicine
MESH: Animals
MESH: Ornipressin
Cells
Cultured
Respiratory Burst
Neurons
Membrane potential
0303 health sciences
General Neuroscience
MESH: Vasotocin
Hyperpolarization (biology)
MESH: Respiratory Burst
CNQX
[SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]
MESH: Cells
Cultured
medicine.drug
MESH: Rats
Hypothalamus
AMPA receptor
Biology
Article
03 medical and health sciences
Bursting
Organ Culture Techniques
MESH: Oxytocin
medicine
Animals
[SDV.NEU] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]
Rats
Wistar
030304 developmental biology
MESH: Rats
Wistar
MESH: Hypothalamus
Oxytocin receptor
MESH: Organ Culture Techniques
Rats
MESH: Nerve Net
nervous system
chemistry
Synapses
Linear Models
Nerve Net
Neuroscience
030217 neurology & neurosurgery
Zdroj: Journal of Neuroscience
Journal of Neuroscience, Society for Neuroscience, 1998, 18, pp.6641-9
HAL
ISSN: 1529-2401
0270-6474
DOI: 10.1523/jneurosci.18-17-06641.1998
Popis: During lactation and parturition, magnocellular oxytocin (OT) neurons display a characteristic bursting electrical activity responsible for pulsatile OT release. We investigated this activity using hypothalamic organotypic slice cultures enriched in magnocellular OT neurons. As shown here, the neurons are functional and actively secrete amidated OT into the cultures. Intracellular recordings were made from 23 spontaneously bursting and 28 slow irregular neurons, all identified as oxytocinergic with biocytin and immunocytochemistry. The bursting electrical activity was similar to that described in vivo and was characterized by bursts of action potentials (20.1 +/- 4.3 Hz) lasting approximately 6 sec, over an irregular background activity. OT (0.1-1 microM), added to the medium, increased burst frequency, reducing interburst intervals by 70%. The peptide also triggered bursting in 27% of nonbursting neurons. These effects were mimicked by the oxytocin receptor (OTR) agonist [Thr4, Gly7]-OT and inhibited by the OTR antagonist desGly-NH2d(CH2)5[D-Tyr2,Thr4]OVT. Burst rhythmicity was independent of membrane potential. Hyperpolarization of the cells unmasked volleys of afferent EPSPs underlying the bursts, which were blocked by CNQX, an AMPA/kainate receptor antagonist. Our results reveal that OT neurons are part of a hypothalamic rhythmic network in which a glutamatergic input governs burst generation. OT neurons, in turn, exert a positive feedback on their afferent drive through the release of OT.
Databáze: OpenAIRE
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