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Neonatal Treatment (neonatal + treatment)

Distribution by Scientific Domains

Medical Sciences	40%

Selected Abstracts

Long maternal separation has protective effects in rats exposed to activity-based anorexia

DEVELOPMENTAL PSYCHOBIOLOGY, Issue 8 2009
O. Carrera
Abstract This study examined the effect of three neonatal treatments of maternal separation during infancy in young adult rats exposed to standard activity-based anorexia (ABA) consisting of food restriction plus free access to an activity wheel. During the first 20 postnatal days of life rat pups were exposed to periods of either brief maternal separation (BMS, 15,min), long maternal separation (LMS, 180,min), or were non-handled (NH). Thereafter, male and female rats were exposed to ABA. Neonatal treatment produced no significant differences in the survival time of male rats, whereas survival was greater in female rats exposed to LMS than in NH rats under ABA procedure. In conclusion, prolonged maternal separation appears to promote resistance in female animals subjected to harsh ABA life-threatening conditions. © 2009 Wiley Periodicals, Inc. Dev Psychobiol 51: 616,624, 2009 [source]

Identification of prostaglandin E2 receptors mediating perinatal masculinization of adult sex behavior and neuroanatomical correlates

DEVELOPMENTAL NEUROBIOLOGY, Issue 12 2008
Christopher L. Wright
Abstract Prostaglandin E2 (PGE2) mediates the organization of male rat sexual behavior and medial preoptic area (MPOA) neuroanatomy during a sensitive perinatal window. PGE2 is up-regulated in response to estradiol, and initiates a two-fold increase in dendritic spines densities on neurons. All the four receptors for PGE2 and EP1-4 are present in developing POA, a critical region controlling male sexual behavior. Previous studies explored that EP receptors are involved in PGE2-induction of neonatal levels of spinophilin protein, a surrogate marker for dendritic spine formation, but did not assess behavioral masculinization. Here, we used two approaches, suppression of EP receptor expression with antisense oligonucleotides and activation of EP receptors with selective agonists, to test which receptors are necessary and sufficient, respectively, for the effects of PGE2 on behavior and neuronal morphology. In female rats, neonatal treatment with antisense oligonucleotides against EP2 or EP4 but not EP1 or EP3 completely prevented the expression of adult behavior organized by PGE2 exposure. The effects of ONO-DI-004, ONO-AE-259-01, ONO-AE-248, and ONO-AE1-329 (EP1-4 agonists respectively) were equivalent to PGE2 treatment, which suggests activating any EP receptor neonatally suffices in masculinizing sex behavior. When given alone, not all EP agonists increased neonatal POA spinophilin levels; yet giving each agonist neonatally increased adult levels. Moreover, adult spinophilin levels significantly correlated with two measures of male sexual behavior. The body of evidence suggests that EP2 and EP4 are both necessary and sufficient for PGE2-induced masculinization of sex behavior, whereas EP1 and EP3 provide redundant roles. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008 [source]

Blunted Pituitary-Adrenocortical Stress Response in Adult Rats Following Neonatal Dexamethasone Treatment

JOURNAL OF NEUROENDOCRINOLOGY, Issue 10 2000
K. Felszeghy
Abstract Glucocorticoids have a prominent impact on the maturation of the stress-related neuroendocrine system and on the postnatal establishment of adaptive behaviour. The present study aimed at investigating the stress responsiveness of the hypothalamo-pituitary-adrenocortical (HPA) axis in young and adult rats after neonatal treatment with the synthetic glucocorticoid agonist, dexamethasone. Newborn male Wistar rats were injected s.c. with 1 µg/g dexamethasone on postnatal days 1, 3 and 5. Circulating adrenocorticotropic hormone (ACTH) and corticosterone concentrations were measured in the resting state and following a 30-min cold stress at the age of 10 days, as well as after a 30-min restraint stress at the age of 14 weeks. Also in adults, pituitary and adrenocortical hormone responsiveness was evaluated after i.v. administration of 2 µg/kg corticotropin releasing hormone (CRH). In addition, glucocorticoid (GR) and mineralocorticoid receptor (MR) binding capacities were assessed in the pituitaries of adult rats. The results showed that at day 10 basal ACTH concentration was elevated while the cold stress-evoked ACTH response was attenuated in the dexamethasone-treated rats. As adults, treated rats showed a suppressed elevation of both ACTH and corticosterone plasma cncentrations in response to restraint, while basal hormonal concentrations were not altered. There was no difference in the magnitude of the CRH-induced elevation of ACTH and corticosterone concentrations initially; however, the dexamethasone-treated animals showed a prolonged secretion of both hormones. These animals also showed a selective decrease in pituitary GR binding capacity. Neonatal dexamethasone treatment strongly suppressed body weight gain, and adrenal and thymus weights in the early phase of postnatal development. By adulthood, the body and adrenal weights were normalized while thymus weight was greater than in controls. These findings indicate that neonatal dexamethasone treatment permanently alters HPA axis activity by reducing stress responses to cold and restraint probably through supra-pituitary actions, and by decreasing the effectiveness of feedback through a diminished GR binding in the pituitary. [source]

Renal function and volume of infants born with a very low birth-weight: a preliminary cross-sectional study

ACTA PAEDIATRICA, Issue 8 2010
M Zaffanello
Abstract Aim:, The aim of our study was to compare the function and volumes of kidneys of very low birth-weight (VLBW) and of extremely low birth-weight (ELBW) infants at pre-school ages. Patients and methods:, We did a revision of the neonatal records of infants born in our hospital that weighed ,1500 g at birth. The children were divided into two groups according to their weight at birth: ELBW (<1000 g) and VLBW (1000,1500 g). At the age of 5.7 ± 1.4 years, the children underwent clinical, laboratory and ultrasound renal assessments. Results:, Sixty-nine children fulfilled the requirements for the study. The rate of neonatal treatment with aminoglycosides was higher in ELBW preterms. Renal function parameters, i.e. estimated glomerular filtration rate and albuminuria, did not differ between the two groups of children. Urinary ,1-microglobulin excretion was significantly higher and kidneys were significantly smaller in the ELBW group than in the VLBW group. Conclusion:, No impairment or differences in renal parameters were found in pre-school children born ELBW compared with those born with VLBW, except for differences in kidney volume, renal cortical thickness and urinary ,1-microglobulin excretion. Thus, patients born with ELBW would require a longer follow-up period. [source]