title: Delta opioid receptor immunoreactive boutons appose bulbospinal CI neurons in the rat.
abstract: Bulbospinal sympathoexcitatory neurons in the rostral ventrolateral medulla are inhibited by activation of delta opioid receptors. However, it is not known whether this opioidergic effect is pre- or post- synaptic. Here, using retrograde tracing and immunocytochemistry in adult rats, we provide evidence that the delta opioid receptor is located on boutons that are presynaptic to both catecholaminergic and non-catecholaminergic neurons that project to the spinal cord. We suggest that the sympathoinhibitory action of delta opioid receptor activation in the rostral ventrolateral medulla is mediated presynaptically, resulting in a reduction of excitatory neurotransmitter release from boutons that oppose sympathoexcitatory bulbospinal neurons.
authors.affiliation: Department of Pharmacology, University of Sydney, Australia.
authors.forename: T
authors.initials: T
authors.lastname: Stasinopoulos
authors.forename: A K
authors.initials: AK
authors.lastname: Goodchild
authors.forename: M J
authors.initials: MJ
authors.lastname: Christie
authors.forename: J
authors.initials: J
authors.lastname: Chalmers
authors.forename: P M
authors.initials: PM
authors.lastname: Pilowsky
mesh_terms: D000320:Adrenergic Fibers / Q000378:metabolism* / Q000648:ultrastructure; D000818:Animals; D004299:Dopamine beta-Hydroxylase / Q000378:metabolism; D004525:Efferent Pathways / Q000166:cytology / Q000378:metabolism*; D004837:Epinephrine / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D008526:Medulla Oblongata / Q000166:cytology / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D017729:Presynaptic Terminals / Q000378:metabolism* / Q000648:ultrastructure; D051381:Rats; D017207:Rats, Sprague-Dawley; D017465:Receptors, Opioid, delta / Q000378:metabolism*; D013116:Spinal Cord / Q000166:cytology / Q000378:metabolism*
chemical_list: D017465:Receptors, Opioid, delta; D004299:Dopamine beta-Hydroxylase; D004837:Epinephrine