Open AccessEffects of exposure conditions to footshocks early in life on spontaneous locomotor activity at maturity in rats
Author(s) -
Dong Goo Kim,
Seoul Lee,
Jong Su Lim
Publication year - 1999
Publication title -
yonsei medical journal/yonsei medical journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.702
H-Index - 63
eISSN - 1976-2437
pISSN - 0513-5796
DOI - 10.3349/ymj.1999.40.2.124
Subject(s) - nature versus nurture , learned helplessness , developmental psychology , psychology , privation , stimulus (psychology) , trait , physiology , biology , neuroscience , circadian rhythm , cognitive psychology , genetics , sleep deprivation , computer science , programming language
Both genetic and environmental factors are involved in establishing a behavior. An animal study was done to determine the characteristics of interaction between genetic (nature) and environmental (nurture) factors. Delivery of footshocks (0.8 mA x 60 times, at random) early in life was used as the environmental stimulus. As the footshock was delivered repeatedly, a rat showed helplessness behavior and the number of shocks necessary to elicit helplessness was measured to quantify the trait of an animal in coping with the aversive environmental stimulus. The nocturnal ambulatory activity at adulthood was measured as a behavioral expression of the nature-nurture interaction. Although the experience of footshocks early in life did not significantly alter average activity levels at adulthood, the activity was positively correlated with the number of shocks necessary to elicit helplessness (nature) while receiving footshocks (nurture) on postnatal day 14. Additionally, a second exposure to identical shock parameters on postnatal day 21 reversed the relationship. These results clearly showed that an interaction between nature and nurture during infancy leads to substantial behavioral alterations later in life, and suggest that the nature-dependent determination of an adult behavior can be modified in different directions by the conditions of an environmental experience early in life.