Differential regulation of CaMKII inhibitor beta protein expression after exposure to a novel context and during contextual fear memory formation.

Journal article

Understanding of the molecular basis of long-term fear memory (fear LTM) formation provides targets in the treatment of emotional disorders. Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) is one of the key synaptic molecules involved in fear LTM formation. There are two endogenous inhibitor proteins of CaMKII, CaMKII N alpha and N beta, which can regulate CaMKII activity in vitro. However, the physiological role of these endogenous inhibitors is not known. Here, we have investigated whether CaMKII N beta protein expression is regulated after contextual fear conditioning or exposure to a novel context. Using a novel CaMKII N beta-specific antibody, CaMKII N beta expression was analysed in the naïve mouse brain as well as in the amygdala and hippocampus after conditioning and context exposure. We show that in naïve mouse forebrain CaMKII N beta protein is expressed at its highest levels in olfactory bulb, prefrontal and piriform cortices, amygdala and thalamus. The protein is expressed both in dendrites and cell bodies. CaMKII N beta expression is rapidly and transiently up-regulated in the hippocampus after context exposure. In the amygdala, its expression is regulated only by contextual fear conditioning and not by exposure to a novel context. In conclusion, we show that CaMKII N beta expression is differentially regulated by novelty and contextual fear conditioning, providing further insight into molecular basis of fear LTM.

Authors: Radwańska, K; Tudor-Jones, A; Mizuno, K; Pereira, G; Lucchesi, W

• Publication status: Published
• Journal: Genes, brain, and behavior
• Volume: 9
• Issue: 6
• Pages: 648-657
• Publication date: 2010-08-01
• DOI: 10.1111/j.1601-183x.2010.00595.x
• EISSN: 1601-183X
• ISSN: 1601-1848
• Language: English
• Keywords: Up-Regulation; Immunohistochemistry; Gene Expression; Calcium-Calmodulin-Dependent Protein Kinase Type 2; Memory; Mice, Inbred C57BL; Amygdala; Olfactory Bulb; Animals; Blotting, Western; Conditioning, Classical; Prosencephalon; Enzyme Inhibitors; Mice; Fear; Hippocampus; Behavior, Animal