Two-way active avoidance training-specific increases in phosphorylated cAMP response element-binding protein in the dorsal hippocampus, amygdala, and hypothalamus.
Previous studies have demonstrated that the activation of pontine-wave (P-wave) generating cells in the brainstem during post-training rapid eye movement (REM) sleep is critical for the consolidation of memory for two-way active avoidance (TWAA) learning in the rat. Here, using immunocytochemistry, we investigated the spatio-temporal distribution of CREB phosphorylation within different parts of the dorsal hippocampus, amygdala, and hypothalamus following a session of TWAA training in the rat. We show that the TWAA training trials increased phosphorylation of CREB (p-CREB) in the dorsal hippocampus, amygdala, amygdalo-hippocampal junction (AHi), and hypothalamus. However, the time intervals leading to training-induced p-CREB activity were different for different regions of the brain. In the dorsal hippocampus, p-CREB activity was maximal at 90 min and this activity disappeared by 180 min. In the AHi, activity of the p-CREB peaked by 180 min and disappeared by 360 min. In the amygdala, the p-CREB activity peaked at 180 min and still remained higher than the control at the 360 min interval. In the hypothalamus, at 90 min p-CREB activity was present only in the ventromedial hypothalamus; however, by 180 min this p-CREB activity was also present in the dorsal hypothalamus, perifornical area, and lateral hypothalamus. By 360 min, p-CREB activity disappeared from the hypothalamus. This TWAA training trials-induced spatiotemporal characteristic of CREB phosphorylation, for the first time, suggests that REM sleep P-wave generator activation-dependent memory processing involves different parts of the dorsal hippocampus, amygdala, and hypothalamus.
Saha
Subhash
S
Sleep and Cognitive Neuroscience Laboratory, Department of Psychiatry, and Program in Behavioural Neuroscience, Boston University School of Medicine, Building M-902, 715 Albany Street, Boston, MA 02118, USA.
Datta
Subimal
S
D000679:Amygdala / Q000166:cytology / Q000378:metabolism*; D000818:Animals; D001362:Avoidance Learning / Q000502:physiology*; D001522:Behavior, Animal; D002452:Cell Count / Q000379:methods; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology*; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism*; D007031:Hypothalamus / Q000166:cytology / Q000378:metabolism*; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D009474:Neurons / Q000378:metabolism; D010766:Phosphorylation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013194:Staining and Labeling / Q000379:methods; D013997:Time Factors
D017362:Cyclic AMP Response Element-Binding Protein