A developmental dissociation of context and GABA effects on extinguished fear in rats.
Although extinction has attracted considerable attention in recent years, there has been very little empirical work on extinction during development. Using Pavlovian fear conditioning, the authors provide evidence for developmental differences in extinction. Specifically, Postnatal Day (PND) 23 rats exhibited recovery of an extinguished freezing response to an auditory conditioned stimulus when tested in a context different from that in which extinction occurred (i.e., renewal) or when injected with the gamma-amino butyric acid (GABA) inverse agonist FG7142 prior to test. In contrast, PND 16 rats failed to exhibit either of these effects, although a subsequent experiment demonstrated that FG7142 alleviated spontaneous forgetting in PND 16 rats. Taken together, it appears that there are fundamental differences in the processes involved in extinction across development.
Kim
Jee Hyun
JH
School of Psychology, The University of New South Wales, Sydney, NSW, Australia. jkim@psy.unsw.edu.au
Richardson
Rick
R
D000161:Acoustic Stimulation / Q000379:methods; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001522:Behavior, Animal / Q000187:drug effects; D002243:Carbolines / Q000494:pharmacology; D003214:Conditioning, Classical / Q000187:drug effects*; D003463:Cues; D004305:Dose-Response Relationship, Drug; D005108:Extinction, Psychological / Q000187:drug effects*; D005239:Fear; D018756:GABA Antagonists / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D002243:Carbolines; D018756:GABA Antagonists; D005680:gamma-Aminobutyric Acid; C035874:FG 7142