Juvenile rats show reduced c-fos activity in neural sites associated with aversion to pups and inhibition of maternal behavior.
Juvenile rats (18-23 days old) interact avidly with pups as novel stimuli and show maternal behavior after only 1-3 days of pup exposure; adults initially avoid pups and require 3-9 days of pup exposure. Upon exposure to pups as novel stimuli, adults had more c-Fos-immunoreactive neurons in the hypothalamus and amygdala--regions associated with aversion to pups--than adults exposed to familiar pup stimuli (maternal) or not exposed to pups (p < .05). In juvenile rats exposed to pups as novel stimuli, only the medial amygdala had a small significant increase of c-Fos neurons. In juveniles, this blunted engagement of c-Fos neurons may reflect the diminished activation of inhibitory neurons, facilitating the interaction of juveniles with pups as novel stimuli and onset of maternal behavior.
Olazábal
D E
DE
Center for Molecular and Behavioral Neuroscience, Rutgers, The State University of New Jersey, Camden, NJ, US. dolazab@emory.edu
Morrell
J I
JI
D000367:Age Factors; D000679:Amygdala / Q000166:cytology*; D000818:Animals; D000831:Animals, Newborn; D001522:Behavior, Animal; D002452:Cell Count / Q000379:methods; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D007031:Hypothalamus / Q000166:cytology*; D007150:Immunohistochemistry / Q000379:methods; D007774:Lactation / Q000502:physiology; D008297:Male; D008425:Maternal Behavior / Q000502:physiology*; D009474:Neurons / Q000378:metabolism*; D009714:Nucleus Accumbens / Q000166:cytology; D011247:Pregnancy; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D051381:Rats
D016760:Proto-Oncogene Proteins c-fos