Early Experiences Accelerate Maturation of the 24-Hour Adrenocortical Rhythm

Rats reared under 12-hour alternating periods of light and dark were killed at times corresponding to the times at which the maximum or minimum plasma corticosterone concentrations occur in mature animals. The characteristic 24-hour adrenocortical rhythm was first observed in rats 21 to 25 days old. In rats handled or stimulated with electric shock, the rhythm developed as early as 16 days.

[1]  S. Levine.  Influence of infantile stimulation on the response to stress during preweaning development , 1968 .

[2]  R. Ader.  Behavioral and Physiological Rhythms and the Development of Gastric Erosions in the Rat , 1967, Psychosomatic medicine.

[3]  S. B. Friedman,et al.  Plasma Corticosterone Response to Parameters of Electric Shock Stimulation in the Rat , 1967, Psychosomatic medicine.

[4]  J. Kendall,et al.  Maturation of the circadian rhythm of plasma corticosterone in the rat. , 1967, Endocrinology.

[5]  V. Denenberg,et al.  Response of the Adrenal Cortex of the Neonatal Rat after Subjection to Stress , 1966, Nature.

[6]  V. Denenberg,et al.  Response of the infantile rat to stress. , 1966, Endocrinology.

[7]  S. Levine,et al.  Hormonal influences on brain organization in infant rats. , 1966, Science.

[8]  S. Leeman,et al.  OBSERVATIONS ON ADRENAL RHYTHMICITY AND ASSOCIATED PHENOMENA IN THE RAT: EFFECT OF LIGHT ON ADRENOCORTICAL FUNCTION; MATURATION OF THE HYPOTHALAMIC NEUROSECRETORY SYSTEM IN RELATION TO ADRENAL SECRETION * , 1964, Annals of the New York Academy of Sciences.

[9]  D. Glick,et al.  FLUOROMETRIC DETERMINATION OF CORTICOSTERONE AND CORTISOL IN 0.02-0.05 MILLILITERS OF PLASMA OR SUBMILLIGRAM SAMPLES OF ADRENAL TISSUE. , 1964, Endocrinology.

[10]  P. Saba,et al.  DIURNAL RHYTHM IN THE ADRENAL CORTICAL SECRETION AND IN THE RATE OF METABOLISM OF CORTICOSTERONE IN THE RAT. I. IN NORMAL ANIMALS. , 1963, Acta endocrinologica.

[11]  R. Liebelt,et al.  Sex difference in resting pituitary-adrenal function in the rat. , 1963, The American journal of physiology.

[12]  R. Guillemin,et al.  Nychthemeral Variations in Plasma Free Corticosteroid Levels of the Rat.∗ , 1959, Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine.

[13]  S. B. Friedman,et al.  'Emotionality' and adrenal cortical function: effects of strain, test, and the 24-hour corticosterone rhythm. , 1967, Animal behaviour.

[14]  G. M. Hughes.  Comparative Physiology of Vertebrate Respiration , 1963 .