Behavioral development following daily episodes of mother-infant separation in the rat.
Use of dermal or inhalation routes of maternal exposure during the postnatal period in rodent developmental neurotoxicity evaluations would be most practical if dams could be separated from their pups during the exposure period. However, this procedure raises questions concerning the effects of mother-infant separation itself on neurotoxicity endpoints. In the present study, Sprague-Dawley rat pups were either maternally deprived in warm incubators for 6 hr each day (7:00 AM-1:00 PM) or left with their dams (control), from Postnatal Day 4-20 (PND4-20), and were tested on a range of endpoints commonly used in developmental neurotoxicology. These included motor activity (PND13, 17, 19, 21, 29, 60), olfactory learning (PND18) and retention (PND25), T-maze delayed alternation (PND23, 24), acoustic startle response (PND23, 62), and auditory thresholds (PND62). None of the behavioral measures were affected by daily separation. Apparently, interrupting the mother-infant interaction for 6 hr/day has little or no effect by itself on behavioral development, as assessed by these measures.
Stanton
M E
ME
Neurotoxicology Division, U.S. EPA, Research Triangle Park, North Carolina 27711.
Crofton
K M
KM
Lau
C
C
D000375:Aging / Q000523:psychology; D000818:Animals; D001309:Auditory Threshold / Q000502:physiology; D001522:Behavior, Animal / Q000502:physiology*; D003216:Conditioning, Operant / Q000502:physiology; D005260:Female; D008425:Maternal Behavior; D008568:Memory / Q000502:physiology; D009043:Motor Activity / Q000502:physiology; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D013216:Reflex, Startle / Q000502:physiology; D012903:Smell / Q000502:physiology