Detection of novelty, but not memory of spatial habituation, is associated with an increase in phosphorylated cAMP response element-binding protein levels in the hippocampus.
There is a growing body of evidence showing that the formation of associative memories is associated with an increase in phosphorylated cAMP response element-binding protein (pCREB) levels. We recently reported increased pCREB levels in the rat hippocampus after an exploration to a novel environment. In the present work, we studied whether this increment in CREB activation is associated with the formation of memory of habituation to a novel environment or with the detection of novelty. Rats were submitted to consecutive open field sessions at 3-h intervals. Measurement of the hippocampal pCREB level, carried out 1 h after each training session, showed that (1) it did not increase when rats explored a familiar environment; (2) it did not increase after a reexposure that improves the memory of habituation; (3) it increased after a brief novel exploration unable to form memory of habituation; and (4) it increased in amnesic rats for spatial habituation. Taken as a whole, our results suggest that the elevated pCREB level after a single open field exploration is not associated with the memory formation of habituation. It is indeed associated with the detection of a novel environment.
Winograd
Milena
M
Instituto de Biología Celular y Neurociencias, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.
Viola
Haydée
H
D000818:Animals; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D005106:Exploratory Behavior / Q000502:physiology*; D006185:Habituation, Psychophysiologic / Q000502:physiology*; D006624:Hippocampus / Q000378:metabolism*; D007858:Learning / Q000502:physiology; D008297:Male; D008568:Memory / Q000502:physiology*; D008569:Memory Disorders / Q000473:pathology / Q000503:physiopathology; D010766:Phosphorylation; D051381:Rats; D017208:Rats, Wistar; D013028:Space Perception / Q000502:physiology*
D017362:Cyclic AMP Response Element-Binding Protein