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Neurohypophysial peptides as retrograde transmitters in the supraoptic nucleus of the rat
Author(s) -
Pittman Quentin J.,
Hirasawa Michiru,
Mouginot Didier,
Kombian Samuel B.
Publication year - 2000
Publication title -
experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0958-0670
DOI - 10.1111/j.1469-445x.2000.tb00017.x
Subject(s) - supraoptic nucleus , oxytocin , neuroscience , excitatory postsynaptic potential , vasopressin , neurotransmission , oxytocin receptor , chemistry , postsynaptic potential , nucleus , magnocellular cell , glutamate receptor , neuropeptide , medicine , biology , endocrinology , inhibitory postsynaptic potential , receptor , biochemistry
A possible role for vasopressin and oxytocin in the physiology of the supraoptic nucleus was investigated using nystatin‐perforated patch recording in acute brain slices from the rat containing the supraoptic nucleus. We observed that exogenously applied oxytocin reduced glutamate‐mediated synaptic transmission by acting at a presynaptic oxytocin receptor. Endogenous oxytocin, released either by afferent excitation (tetanus) or by postsynaptic depolarization of the recorded magnocellular neurone caused a similar reduction of excitatory input and this could be blocked with an oxytocin antagonist. Thus endogenous oxytocin, released from magnocellular dendrites, acts as a retrograde transmitter to reduce afferent excitation. We discuss the possible significance of these results in terms of the physiological role of oxytocin in the intact animal and suggest possible avenues for further experimentation.