Long-lasting changes in stress-induced corticosterone response and anxiety-like behaviors as a consequence of neonatal maternal separation in Long-Evans rats

Author: Kalinichev, Mikhail; Easterling, Keith W.; Plotsky, Paul M.; Holtzman, Stephen G.

Description: Early neonatal environmental factors appear to have powerful and long-lasting influences on an organism’s physiology and behavior. Long-Evans male rats separated from their dam for 3 h daily over the first 2 weeks of life (maternally separated, MS rats) when tested as adults exhibit exaggerated behavioral and neuroendocrine responses to stress compared to 15-min separated (handled, H) animals. The purpose of this study was to compare male and female adult rats that were MS, H or were undisturbed (nonhandled, NH) as neonates in anxiety-like behaviors, in the elevated plus-maze, and in response to startle-inducing auditory stimuli. We confirmed that MS males oversecrete corticosterone (CORT; 2.5-5 times) in response to mild handling stress. MS males and females were less likely to explore open arms of the plus-maze. MS males exhibited 35% higher startle amplitudes compared to controls. Furthermore, MS males were more likely to emit ultrasonic vocalizations in response to startle than were H controls. However, MS and control females did not differ in auditory startle response or in startle-induced ultrasonic vocalizations. Therefore, experiencing maternal separation results in a long-lasting increase in anxiety-like behaviors that occurs in a sex-dependent manner.

Subject headings: Acoustic Stimulation; Animals; Animals, Newborn; Anxiety; Corticosterone; Female; Male; Maternal Deprivation; Pregnancy; Rats; Rats, Long-Evans; Stress, Physiological; Time; Vocalization; Animal

Publication year: 2002

Journal or book title: Pharmacology, Biochemistry, and Behavior

Volume: 73

Issue: 1

Pages: 131-140

Find the full text: https://www.sciencedirect.com/science/article/pii/S0091305702007815

Find more like this one (cited by): https://scholar.google.com/scholar?cites=12235186693705473138&as_sdt=1000005&sciodt=0,16&hl=en

Serial number: 3794

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