Regulation Of CAMP Responsive Element Binding Protein To Stress In Rat Amygdala And Hippocampal Formation

Amygdala (AM) and hippocampal formation (HF) are important structures relating with emotional learning and memory. Transcription factor, cAMP-responsive element binding protein (CREB) in AM and HF plays important roles in memory modulating processes. CREB is a nuclear protein and is widely accepted as prototypical stimulus-inducible transcription factor. CREB is activated in response to a vast array of physiological stimuli and then becames phosphorylated CREB (pCREB). Neurophysiological and neuropharmacological studies said that CREB may regulate gene transcription and protein synthesis to maintain the long term and sustaining changing of synaptic efficiency during the long-term process of synaptic plasticity. But we can not tell exactly via what kind of neurons in AM and HF CREB regulate these processes. We intend to further investigate : â‘ The expression of pCREB in AM and HF after stress. â‘¡In what kinds of neurons pCREB are expressed. â‘¢The relationship between pCREB expression and activity of NMD A receptors. We have done as follows:1. We used the animal model, forced swimming (FS) as emotional stimuli and the experiment methods such as, immunocytochemistry, western-blotting with anti-pCREB antibody. The distributing profiles and changing rules of pCREB immunoreactive nuclei in amygdala and hippocampal formation of both control and experiment groups were investigated. The neuronal types of pCREB immunoreactive nuclei were analyzed by double-labelling immunocytochemistry with anti-pCREB, anti-Glu and anti-PV antibodies. The results were: â‘  The number of pCREB immunoreactive neuclei and total amount of pCREB in the subnuclei of rat amygdala, Dentate gyrus (DG) and Cornu Ammonis 3(CA3) were increased after FS. The rule of this kind of changing was of region- and time-specific. â‘¡ pCREB immunoreactive neuclei were expressed in glutamate immunoreactive neurons and were devoid in interneurons. These results suggested that pCREB in limbic system regulated the FS...