title: Morphine treatment in early life alters glutamate uptake in the spinal synaptosomes of adult rats.
abstract: Morphine exposure during the neonatal period can promote changes in pain signaling pathways that can be expressed as an increased nociceptive response in adult life. Glutamate is the major excitatory neurotransmitter in primary afferent terminals and plays a critical role in normal spinal excitatory synaptic transmission. Considering the importance of a better understanding of the mechanisms that underlie nociceptive changes throughout the life course, the aim of this study was investigate the effects of repeated morphine administration at postnatal days 8 (P8) to 14 (P14) on glutamate uptake in spinal synaptosomes at P30 and P60. The morphine group showed decreased [3H]-glutamate uptake as compared to control groups in both P30 and P60. These findings suggest that morphine exposure in early life leads to changes in glutamatergic signaling at least until the 60th day of age, which may lead to increased levels of glutamate in the spinal synaptic cleft and, consequently, an increased nociceptive response in adult life. Thus, this study highlights the importance of conducting research in this field to provide a comprehensive knowledge of the long-term effects of early-life morphine treatment on nociceptive pathways.
authors.affiliation: Laboratory of Pharmacology of Pain and Neuromodulation: Animal Models, Department of Pharmacology, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90050-170, Brazil.
authors.forename: Joanna Ripoll
authors.initials: JR
authors.lastname: Rozisky
authors.forename: Deusa
authors.initials: D
authors.lastname: Vendite
authors.forename: Fernanda Urruth
authors.initials: FU
authors.lastname: Fontella
authors.forename: Yasmine
authors.initials: Y
authors.lastname: Nonose
authors.forename: Gabriela
authors.initials: G
authors.lastname: Laste
authors.forename: Carla
authors.initials: C
authors.lastname: Dalmaz
authors.forename: Wolnei
authors.initials: W
authors.lastname: Caumo
authors.forename: Iraci L S
authors.initials: IL
authors.lastname: Torres
mesh_terms: D000375:Aging / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D018698:Glutamic Acid / Q000378:metabolism*; D008297:Male; D009020:Morphine / Q000008:administration & dosage*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D018377:Neurotransmitter Agents / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013116:Spinal Cord / Q000187:drug effects / Q000378:metabolism*; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism*
chemical_list: D018377:Neurotransmitter Agents; D018698:Glutamic Acid; D009020:Morphine