Abstract
The neuropeptide oxytocin (OT) and its OT antagonists (OTA) in infant rats affect their behavior as adults. In this study we attempted to determine whether treating rats on the day of birth (postnatal day 1) with OT or OTA would affect brain OT levels of these rats as adults. Rat pups were injected with OT (3 μg), OTA (0.3 μg) or saline vehicle ip on postnatal day 1. As 60-day-old adults, treated rats were killed, and the OT content in their medial preoptic areas (MPOAs), medial hypothalami (MH) and pituitaries were assayed. In females, treatment with OTA on postnatal day 1 significantly decreased pituitary OT levels as adults. In males, by contrast, treatment with OTA on postnatal day 1 resulted in increased pituitary OT levels when they become adults compared to male rats treated with OT on postnatal day 1. There were no significant effects of neonatal treatment on OT levels in either the MH or MPOA. Day 1 postnatal treatment with OT or OTA had a long-term sexually dimorphic effect on OT levels in the pituitary.
Key words
Oxytocin - Oxytocin antagonist - Pituitary - Hypothalamus - Paraventricular nucleus - Development - Neonatal treatments
References
-
1
Nishimori K, Young L J, Guo Q, Wang Z, Insel T R, Matzuk M M.
Oxytocin is required for nursing but is not essential for parturition or reproductive behavior.
Proc Natl Acad Sci U S A.
1996;
93
11 699-11 704
-
2
Amico J A, Finley B E.
Breast stimulation in cycling women, pregnant women and a woman with induced lactation: pattern of release of oxytocin, prolactin and luteinizing hormone.
Clin Endocrinol (Oxf).
1986;
25
97-106
-
3
Johnston J M, Amico J A.
A prospective longitudinal study of the release of oxytocin and prolactin in response to infant suckling in long term lactation.
J Clin Endocrinol Metab.
1986;
62
653-7
-
4
Kroeger M.
Oxytocin: key hormone in sexual intercourse, parturition, and lactation.
Birth Gaz.
1996;
13
28-30
-
5
Rojkittikhun T, Uvnas-Moberg K, Einarsson S, Lundeheim N.
Effects of weaning on plasma levels of prolactin, oxytocin, insulin, glucagon, glucose, gastrin and somatostatin in sows.
Acta Physiol Scand.
1991;
141
295-303
-
6
Soloff M S, Alexandrova M, Fernstrom M J.
Oxytocin receptors: triggers for parturition and lactation?.
Science.
1979;
204
1313-1315
-
7
Young W S 3rd
, Shepard E, Amico J, Hennighausen L, Wagner K U, LaMarca M E, McKinney C, Ginns E I.
Deficiency in mouse oxytocin prevents milk ejection, but not fertility or parturition.
J Neuroendocrinol.
1996;
8
847-853
-
8
Boccia M L, Pedersen C A.
Brief vs. long maternal separations in infancy: contrasting relationships with adult maternal behavior and lactation levels of aggression and anxiety.
Psychoneuroendocrinology.
2001;
26
657-72
-
9
Carter C S, Altemus M.
Integrative functions of lactational hormones in social behavior and stress management.
Ann N Y Acad Sci.
1997;
807
164-174
-
10
Carter C S, Lederhendler I, Kirkpatrick B.
The integrative neurobiology of affiliation. Introduction.
Ann N Y Acad Sci.
1997;
807
xiii-xviii
-
11
Carter C S, Altemus M, Chrousos G P.
Neuroendocrine and emotional changes in the post-partum period.
Prog Brain Res.
2001;
133
241-249
-
12
Fahrbach S, Morrell J I, Pfaff D W.
Oxytocin inducton of short-latency maternal behavior in nulliparous, estrogen-primed female rats.
Hormones and Behavior.
1984;
18
267-286
-
13
Johns J M, Caldwell J D, Pedersen C A.
Acute cocaine treatment decreases oxytocin levels in the rat hippocampus.
Neuropeptides.
1993;
24
165-169
-
14
Keverne E B, Kendrick K M.
Maternal behaviour in sheep and its neuroendocrine regulation.
Acta Paediatr Suppl.
1994;
397
47-56
-
15
Leckman J F, Herman A E.
Maternal behavior and developmental psychopathology.
Biol Psychiatry.
2002;
51
27-43
-
16
Lin S H, Kiyohara T, Sun B.
Maternal behavior: activation of the central oxytocin receptor system in parturient rats?.
NeuroReport.
2003;
14
1439-1444
-
17
Pedersen C A, Caldwell J D, Walker C, Ayers G, Mason G A.
Oxytocin activates the postpartum onset of rat maternal behavior in the ventral tegmental and medial preoptic areas.
Behav Neurosci.
1994;
108
1163-1171
-
18
Pedersen C A, Ascher J A, Monroe Y L, Prange A J Jr.
Oxytocin induces maternal behavior in virgin female rats.
Science.
1982;
216
648-649
-
19
Pedersen C A, Prange A J Jr.
Induction of maternal behavior in virgin rats after intracerebroventricular administration of oxytocin.
Proc Nat Acad Sci.
1979;
76
6661-6665
-
20
Bales K, Abdelnabi M, Carter C S.
Neonatal injections affect reproductive parameters in male prairie voles.
Hormones and Behavior.
2001;
40
324
-
21
Bales K, Carter C S.
Sex differences and developmental effects of oxytocin on aggression and social behavior in prairie voles (Microtus ochrogaster).
Horm Behav.
2003;
44
178-184
-
22
Bales K, Pfeifer L A, Carter C S.
Sex Differences and Developmental Effects of Manipulations of Oxytocin on Alloparenting and Anxiety in Prairie Voles.
Develop Psychobiol.
2004;
44
123-131
-
23
Cushing B S, Levine N L, Cushing N L.
Neonatal manipulations of oxytocin affect reproductive behavior and reproductive success of adult female prairie voles (Microtus ochrogaster).
Horm Behav.
2005;
47
22-28
-
24
Withuhn T, Kramer K M, Cushing B S.
Early exposure to oxytocin affects the age of vaginal opening and first estrus in female rats.
Physiol Behav.
2003;
8
135-138
-
25
Yamamoto Y, Cushing B S, Kramer K M, Epperson P D, Hoffman G E, Carter C S.
Neonatal manipulations of oxytocin alter expression of oxytocin and vasopressin immunoreactive cells in the paraventricular nucleus of the hypothalamus in a gender-specific manner.
Neuroscience.
2004;
125
947-955
-
26
Greer E R, Caldwell J D, Johnson M F, Prange A J Jr, Pedersen C A.
Variations in concentration of oxytocin and vasopressin in the paraventricular nucleus of the hypothalamus during the estrous cycle in rats.
Life Sci.
1986;
38
2311-2318
-
27
Caldwell J D, Greer E R, Johnson M F, Prange A J Jr, Pedersen C A.
Oxytocin and vasopressin immunoreactivity in hypothalamic and extrahypothalamic sites in late pregnant and postpartum rats.
Neuroendocrinology.
1987;
46
39-47
-
28
Caldwell J D, Jirikowski G F, Greer E R, Pedersen C A.
Medial preoptic area oxytocin and female sexual receptivity.
Behav Neurosci.
1989;
103
655-662
-
29
Cushing B S, Carter C S.
Peripheral pulses of oxytocin increase partner preferences in female, but not male, prairie voles.
Hormones and Behavior.
2000;
37
49-56
-
30
Kramer K M, Cushing B S, Carter C S.
Developmental effects of oxytocin on stress response: single versus repeated exposure.
Physio & Behavior.
2003;
79
775-782
-
31
Haussler H U, Jirikowski G F, Caldwell J D.
Sex differences among oxytocin-immunoreactive neuronal systems in the mouse hypothalamus.
J Chem Neuroanat.
1990;
3
271-276
-
32
Caldwell J D, Brooks P J, Jirikowski G F, Barakat A S, Lund P K, Pedersen C A.
Estrogen alters Oxytocin mRNA levels in the preoptic area.
Journal of Neuroendocrinology.
1989;
1
273-278
-
33
Caldwell J D, Jirikowski G F, Greer E R, Stumpf W E, Pedersen C A.
Ovarian steroids and sexual interaction alter oxytocinergic content and distribution in the basal forebrain.
Brain Res.
1988;
446
236-244
-
34
Jirikowski G F, Caldwell J D, Pilgrim C, Stumpf W E, Pedersen C A.
Changes in immunostaining for oxytocin in the forebrain of the female rat during late pregnancy, parturition and early lactation.
Cell Tissue Res.
1989;
256
411-417
-
35
Jirikowski G F, Caldwell J D, Pedersen C A, Stumpf W E.
Estradiol influences oxytocin-immunoreactive brain systems.
Neuroscience.
1988;
25
237-248
-
36
Jirikowski G F, Caldwell J D, Haussler H U, Pedersen C A.
Mating alters topography and content of oxytocin immunoreactivity in male mouse brain.
Cell Tissue Res.
1991;
266
399-403
-
37
Herbert Z, Jirikowski G F, Petrusz P, Englof I, Caldwell J D.
Distribution of androgen binding globulin in the rat hypothalamo-hypophyseal system, co-localization with oxytocin.
Brain Research.
2003;
992
151-158
-
38
Herbert Z, Weigel S, Marshall A, Caldwell J D, Petrusz P, Peuckert C, Jirikowski G F.
Coexpression of androgen-binding protein (ABP) and oxytocin in the male reproductive tract.
Anatomia, Histologia and Embrylogia.
2005;
34
1-8
-
39
Cushing B S, Yamamoto Y, Hoffman G E, Carter C S.
Central expression of c-Fos in neonatal prairie voles in response to treatment with oxytocin.
Developmental Brain Res.
2003;
143
129-136
-
40
Bales K, Pfeifer L A, Carter C S.
Sex differences and effects of developmental OT on alloparenting and anxiety in prairie voles.
Develop Psychobiol.
2004;
in press
-
41
Sohlstrom A, Brismar K, Carlsson-Skwirut C, Bang P, Uvnas-Moberg K.
Effects of oxytocin on the IGF-axis and some gastrointestinal hormones in ad libitum fed and food-restricted female rats.
Acta Physiol Scand.
1999;
166
223-230
-
42
Sohlstrom A, Olausson H, Brismar K, Uvnas-Moberg K.
Oxytocin Treatment during Early Life Influences Reproductive Performance in ad libitum Fed and Food-Restricted Female Rats.
Biol Neonate.
2002;
81
132-138
-
43
Uvnas-Moberg K, Alster P, Petersson M, Sohlstrom A, Bjorkstrand E.
Postnatal oxytocin injections cause sustained weight gain and increased nociceptive thresholds in male and female rats.
Pediatr Res.
1998;
43
344-348
-
44
Engelmann M, Wotjak C T, Neumann I, Ludwig M, Landgraf R.
Behavioral consequences of intracerebral vasopressin and oxytocin: focus on learning and memory.
Neurosci Biobehav Rev.
1996;
20
341-358
-
45
Uvnas-Moberg K.
Oxytocin may mediate the benefits of positive social interaction and emotions.
Psychoneuroendocrinology.
1998;
23
819-835
J. D. Caldwell, Ph. D.
Department of Biomedical Sciences, University of Illinois College of Medicine at Rockford
1601 Parkview Avenue · Rockford · IL 61107-1897 · USA ·
eMail: Jackc@uic.edu
