学习与记忆-微观课件.ppt

The regulation of gene expression by CREB. CREB-2 functions as a repressor of gene expression. CREB-1, an activator of gene expression, can displace CREB-2. When CREB-1 is phosphorylated by protein kinase A (and other kinases), transcription can ensue. Thanks！ * * * * * * First, their dendrites extend only into the molecular layer, where they branch like a fan, flattened in one plane. Second, Purkinje cell axons synapse on neurons in the deep cerebellar nuclei, which are the major output cells of the cerebellum.Thus, Purkinje cells are in a powerful position to modify the output of the cerebellum. Third, Purkinje cells use GABA as a neurotransmitter, so their influence on cerebellar output is inhibitory. * * * The catalytic domain of CaMKII has several binding sites for ATP and other substrate anchor proteins. It governs the enzyme’s phosphorylation and is shaped in the form of two hexameric rings. The autoinhibitory domain features a pseudosubstrate site. The pseudosubstrate site binds to the protein’s catalytic domain, thus blocking its ability to phosphorylate proteins.[8] The structural feature that governs this autoinhibition is the Threonine 286 residue. Phosphorylation of this site will permanently activate the CaMKII enzyme. Once the Threonine 286 residue has been phosphorylated, the inhibitory domain is blocked from the pseudosubstrate site. This effectively blocks autoinhibition, allowing for permanent activation of the CaMKII enzyme. This enables CamKII to be active, even in the absence of calcium and calmodulin.[9] * * * Outline Aplysia： habituation sensitization associative learning Vertebrates: LTP and LTD Molecular mechanism of LTM Invertebrate Nervous Systems Show Plasticity-Aplysia Habituation in Aplysia: Squirts of water on its siphon causes it to retract its gill. After repeated squirts, the animal retracts the gills less – it has learned that the water poses no danger. at the sensory nerv