Postnatal Touch Stimulation Acutely Alters Corticosterone Levels and Glucocorticoid Receptor Gene Expression in the Neonatal RatJutapakdeegul N. · Casalotti S.O. · Govitrapong P. · Kotchabhakdi N.
aNeurobehavioral Biology Center, Institute of Science and Technology for Research and Development, Mahidol University, Salaya, Nakornpathom, Thailand; bInstitute of Laryngology and Otology, UCL, London, UK
Environmental manipulation early in life can alter the development of the hypothalamic-pituitary-adrenal (HPA) axis by mechanisms that are still unclear. The aim of the present work was to study the acute effects of postnatal touch stimulation, in an attempt to understand the mechanism by which touch stimulation early in life alters the HPA response to stress in adult animals. Rat pups were gently brushed for 15 min daily during the 1st postnatal week. Serum corticosterone levels were determined by radioimmunoassays, while glucocorticoid receptor (GR) gene expression was assayed by semiquantitative reverse transcriptase-polymerase chain reaction. Touch stimulation induced a significant decrease (30–36%) in serum corticosteroid secretion during the 1st and 2nd postnatal day as compared to the unstimulated group. In contrast, GR gene expression in the touch stimulation group was significantly increased in several brain areas such as the hippocampus (19–21%), frontal cortex (26–34%) and midbrain (15–24%). The results thus indicate that neonatal touch stimulation causes acute hormone- secretion and gene-expression changes within the period of stimulation. These changes may be the underlying cause for the permanent changes that have been observed in adult animals touch-stimulated as neonates.
Dr. Nuanchan Jutapakdeegul
Neurobehavioral Biology Center
Institute of Science and Technology for Research and Development
Salaya, Nakornpathom 73170 (Thailand)
Received: August 1, 2001
Accepted: January 15, 2003
Number of Print Pages : 8
Number of Figures : 4, Number of Tables : 1, Number of References : 37
Vol. 25, No. 1, Year 2003 (Cover Date: January-February (Released July 2003))
Journal Editor: A.T. Campagnoni, Los Angeles, Calif.
ISSN: 0378–5866 (print), 1421–9859 (Online)
For additional information: http://www.karger.com/journals/dne