title: Neonatal testosterone exposure influences neurochemistry of non-opioid swim stress-induced analgesia in adult mice.
abstract: The effects of neonatal hormone manipulations on swim stress-induced analgesia (SSIA) magnitude and neurochemical quality were examined in Swiss-Webster mice of both sexes. Previous research has indicated that non-opioid SSIA mechanisms in adult Swiss-Webster mice are sexually dimorphic. Male mice exhibit non-opioid SSIA following a 3-min swim in cold (15 degrees C) water that is antagonized by the non-competitive NMDA antagonist MK-801 (dizocilpine; 0.075 mg/kg), whereas female mice do not display NMDA-mediated analgesia in the presence of estrogen. Since male and female mice show equipotent magnitudes of SSIA, it was concluded that female mice display a neurochemically distinct, estrogen-dependent SSIA mechanism specific to their gender. In the present study, female mice exposed to testosterone during the neonatal period display NMDA-mediated analgesia even in the presence of estrogen in adulthood. Thus, expression of the female-specific, estrogen-dependent SSIA mechanism previously described may be dependent on the absence of testosterone during early ontogeny.
authors.affiliation: Department of Psychology and Brain Research Institute, University of California, Los Angeles, CA 90024 USA Research Service (151W), VA Medical Center and Oregon Health Sciences University, Portland, OR 97211 USA Department of Pharmacology, Cornell University Medical College, New York, NY 10021 USA College of Nursing, Ohio State University, Columbus, OH 43210 USA.
authors.forename: Wendy F
authors.initials: WF
authors.lastname: Sternberg
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Mogil
authors.forename: Benjamin
authors.initials: B
authors.lastname: Kest
authors.forename: Gayle G
authors.initials: GG
authors.lastname: Page
authors.forename: Yet
authors.initials: Y
authors.lastname: Leong
authors.forename: Ving
authors.initials: V
authors.lastname: Yam
authors.forename: John C
authors.initials: JC
authors.lastname: Liebeskind
mesh_terms: D000698:Analgesia; D000818:Animals; D000831:Animals, Newborn; D001835:Body Weight / Q000187:drug effects / Q000502:physiology; D001921:Brain / Q000196:embryology*; D016291:Dizocilpine Maleate / Q000494:pharmacology; D004967:Estrogens / Q000494:pharmacology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005260:Female; D008297:Male; D051379:Mice; D009919:Orchiectomy; D010147:Pain Measurement / Q000187:drug effects; D011247:Pregnancy; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000502:physiology*; D012727:Sex Characteristics; D013315:Stress, Psychological / Q000503:physiopathology*; D013550:Swimming; D013739:Testosterone / Q000494:pharmacology*
chemical_list: D004967:Estrogens; D018691:Excitatory Amino Acid Antagonists; D016194:Receptors, N-Methyl-D-Aspartate; D013739:Testosterone; D016291:Dizocilpine Maleate