Lecture 7 Outline PDF

2024-10-23 Molecular Basis of Implicit Learning NROC36H3F © Arruda Carvalho UTSC Lecture Outline Implicit vs Explicit Memory Implicit Memory in Aplysia Ha...

2024-10-23 Molecular Basis of Implicit Learning NROC36H3F © Arruda Carvalho UTSC Lecture Outline Implicit vs Explicit Memory Implicit Memory in Aplysia Habituation Sensitization Classical Conditioning Long-Term Facilitation PKA and CREB Synapse Specificity Dendritic Protein Synthesis CPEB Olfactory Conditioning in Drosophila Fear Conditioning in Mice © Arruda Carvalho © 2018 Arruda Carvalho UTSC winterUTSC term 1  2024-10-23 Lecture Outline Implicit vs Explicit Memory Implicit Memory in Aplysia Habituation Sensitization Classical Conditioning Long-Term Facilitation PKA and CREB Synapse Specificity Dendritic Protein Synthesis CPEB Olfactory Conditioning in Drosophila Fear Conditioning in Mice © Arruda Carvalho © 2018 Arruda Carvalho UTSC winterUTSC term Implicit vs Explicit Memory Welcome to UTSC! Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC 2  2024-10-23 Molecular Basis of Memory Welcome to UTSC! Kandel, Science, 2001 © Arruda Carvalho UTSC Lecture Outline Implicit vs Explicit Memory Implicit Memory in Aplysia Habituation Sensitization Classical Conditioning Long-Term Facilitation PKA and CREB Synapse Specificity Dendritic Protein Synthesis CPEB Olfactory Conditioning in Drosophila Fear Conditioning in Mice © Arruda Carvalho © 2018 Arruda Carvalho UTSC winterUTSC term 3  2024-10-23 Molecular Basis of Implicit Memory: Habituation Charles Sherrington, 1857-1952 Repeated electrical stimulation of the motor pathways in the cat Decrease in the intensity of certain reflexes Habituation Diminished synaptic effectiveness in the stimulated pathways? http://wellcomeimages.org/indexplus/image/L0014994.html © Arruda Carvalho UTSC Molecular Basis of Implicit Memory: Habituation Richard Thompson Alden Spencer Spinal flexion reflex in cats (= withdrawal of a limb from a noxious stimulus) During habituation, the strength of the input from local excitatory interneurons onto motor neurons in the spinal cord decreased © Arruda Carvalho UTSC 4  2024-10-23 Molecular Basis of Implicit Memory: Habituation Aplysia californica http://www.sci-news.com/othersciences/neuroscience/article01018.html http://www.seaslugforum.net/find/9129 Only 20,000 central neurons! Largest nerve cells in the animal kingdom (up to 1000 m) Easily identifiable © Arruda Carvalho UTSC Nobel Prize Alert “(…) recognizing that the molecular basis of cognitive processes such as learning must first be worked out in simpler systems before they can be understood in the brains of complex mammals such as ourselves.” © Arruda Carvalho UTSC 5  2024-10-23 Molecular Basis of Implicit Memory: Habituation Expelling of seawater and waste When a weak tactile stimulus is applied to the siphon, both the siphon and gill are withdrawn into the mantle cavity for protection under the mantle shelf Kandel, Science, 2001 Repeated stimulation leads to habituation of this reflex © Arruda Carvalho UTSC Molecular Basis of Implicit Memory: Habituation mechanoreceptor Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC 6  2024-10-23 Molecular Basis of Implicit Memory: Habituation Excitation of mechanoreceptor sensory neurons; Glut release Excitatory postsynaptic potentials (EPSPs) in interneurons and motor cells Motor neuron neurotransmitter release Gill withdrawal Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC Molecular Basis of Implicit Memory: Habituation Habituation Excitation of mechanoreceptor sensory neurons; Glut release Excitatory postsynaptic potentials (EPSPs) in interneurons and motor cells Motor neuron neurotransmitter release Gill withdrawal Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC 7  2024-10-23 Molecular Basis of Implicit Memory: Habituation Homosynaptic depression Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC Molecular Basis of Implicit Memory: Habituation Kupferman et al., Science, 1970 © Arruda Carvalho UTSC 8  2024-10-23 Molecular Basis of Implicit Memory: Habituation Short-term! Single session of 10 stimuli = minutes Four sessions (separated by hours to 1 day) = long-term habituation, up to 3 weeks Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC Molecular Basis of Implicit Memory: Habituation Long-term habituation is caused by a decrease in the number of synaptic contacts between sensory and motor neurons In naïve animals 90% of the sensory neurons make physiologically detectable connections with motor neurons. In animals trained for long-term habituation, the incidence of connections is reduced to 30% Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC 9  2024-10-23 Lecture Outline Implicit vs Explicit Memory Implicit Memory in Aplysia Habituation Sensitization Classical Conditioning Long-Term Facilitation PKA and CREB Synapse Specificity Dendritic Protein Synthesis CPEB Olfactory Conditioning in Drosophila Fear Conditioning in Mice © Arruda Carvalho © 2018 Arruda Carvalho UTSC winterUTSC term Sensitization Kandel, Science, 2001 A weak touch to the siphon normally causes only weak, brief siphon and gill withdrawal. Following a single tail shock, that same weak touch produces a much larger response, lasting about 1 hour. Five or more shocks to the tail produce sensitization lasting days to weeks © Arruda Carvalho UTSC 10  2024-10-23 Sensitization Enhancement in synaptic transmission at multiple levels Heterosynaptic potentiation Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC Sensitization Presynaptic Facilitation: 1. PKA phosphorylation of K+ channels, causing their closure Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC 11  2024-10-23 Recap Sensitization 1. PKA phosphorylation of K+ channels, causing their closure cAMP-dependent Protein Phosphorylation can Close K+ Channels Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC Sensitization Presynaptic Facilitation: 1. PKA phosphorylation of K+ channels, causing their closure 2. PKC enhances the functioning of the release machinery directly Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC 12  2024-10-23 Recap Sensitization 2. PKC enhances the functioning of the release machinery directly Brown and Sihra, Handb. Exp. Pharmacol. 2008 © Arruda Carvalho UTSC Recap G Modulation of neurotransmitter release by PKC targets 1. PKC phosphorylation of SNAP-25 PKC phosphorylation of SNAP-25 (S187) increases the association between SNAP-25 and Syntaxin, increasing SNARE complex formation, and thus facilitating exocytosis From Molecules to Networks, © 2014, 2009, 2004 Elsevier Inc © Arruda Carvalho UTSC 13  2024-10-23 Recap Summary of Effects of PKA and PKC on Transmitter Release PKA PKC Phosphorylation of synapsin 1, releasing its tether to actin and promoting vesicle Phosphorylation of SNAP-25, availability promoting SNARE formation Phosphorylation of RIM – alteration of Munc 18 – Regulation of fusion pore Rab3 and Munc13 binding to promote accelerating exocytosis release Phosphorylation of SNAP-25, promoting SNARE formation Phosphorylation of syntaphilin (which competes with SNAP-25 for syntaxin-1A binding) releases syntaxin-1A for SNARE assembly Snapin phosphorylation increases SNAP25-synaptotagmin binding promoting release © Arruda Carvalho UTSC Sensitization Presynaptic Facilitation: 1. PKA phosphorylation of K+ channel, causing it to close 2. PKC enhances the functioning of the release machinery directly Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC 14  2024-10-23 Lecture Outline Implicit vs Explicit Memory Implicit Memory in Aplysia Habituation Sensitization Classical Conditioning Long-Term Facilitation PKA and CREB Synapse Specificity Dendritic Protein Synthesis CPEB Olfactory Conditioning in Drosophila Fear Conditioning in Mice © Arruda Carvalho © 2018 Arruda Carvalho UTSC winterUTSC term Classical Conditioning Pairing of touch of siphon with tail shock leads to an even stronger withdrawal response Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC 15  2024-10-23 Classical Conditioning 1. Siphon touch triggers AP on sensory neuron, leading to Ca2+ influx in presynaptic terminal 2. Tail shock leads to 5-HT release onto sensory neuron presynaptic terminal shortly after Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC Classical Conditioning 1. Siphon touch triggers AP on sensory neuron, leading to Ca2+ influx in presynaptic terminal Activation of Ca2+-sensitive AC (via calmodulin) Mod. From Wang and Storm, Mol Pharm 2003 Increased cAMP production 2. Tail shock leads to 5-HT release onto sensory neuron (from facilitating interneuron) shortly after Further potentiating cAMP production Principles of Neural Science ©McGraw Hill Increased presynaptic facilitation! © Arruda Carvalho UTSC 16  2024-10-23 Recap Summary of Effects of PKA on Transmitter Release PKA Phosphorylation of synapsin 1, releasing its tether to actin and promoting vesicle availability Phosphorylation of RIM – alteration of Rab3 and Munc13 binding to promote release Phosphorylation of SNAP-25, promoting SNARE formation Phosphorylation of syntaphilin (which competes with SNAP-25 for syntaxin-1A binding) releases syntaxin-1A for SNARE assembly Snapin phosphorylation increases SNAP25-synaptobregmin binding promoting release © Arruda Carvalho UTSC Classical Conditioning AC serves as a coincidence detector 1. Siphon touch triggers AP on sensory neuron, leading to Ca2+ influx in presynaptic terminal Activation of Ca2+-sensitive AC (via calmodulin) Mod. From Wang and Storm, Mol Pharm 2003 Increased cAMP production 2. Tail shock leads to 5-HT release onto sensory neuron (from facilitating interneuron) shortly after Further potentiating cAMP production Principles of Neural Science ©McGraw Hill Increased presynaptic facilitation! © Arruda Carvalho UTSC 17  2024-10-23 Lecture Outline Implicit vs Explicit Memory Implicit Memory in Aplysia Habituation Sensitization Classical Conditioning Long-Term Facilitation PKA and CREB Synapse Specificity Dendritic Protein Synthesis CPEB Olfactory Conditioning in Drosophila Fear Conditioning in Mice © Arruda Carvalho © 2018 Arruda Carvalho UTSC winterUTSC term Sensitization – Long term Five spaced training sessions/1 hour = 1 or more days long-term sensitization Continued spaced training over several days = sensitization that persists for weeks Kandel, Science, 2001 Montarolo et al., Science, 1986 © Arruda Carvalho UTSC 18  2024-10-23 Sensitization – Long term Long- but not short-term sensitization is dependent on RNA and protein synthesis A or E ptn AD RNA A RNA Montarolo et al., Science, 1986 © Arruda Carvalho UTSC Sensitization – Long term Long- but not short-term sensitization is dependent on RNA and protein synthesis Anysomicin -Amanitin Montarolo et al., Science, 1986 © Arruda Carvalho UTSC 19  2024-10-23 Sensitization – Long term 1-2 Repeated stimulation causes the level of cAMP to rise and persist for several minutes. PKA catalytic subunits translocate to the nucleus, and recruit MAPK. In the nucleus, PKA and MAPK phosphorylate and activate the cAMP response element-binding (CREB) protein and remove the repressive action of CREB-2, an inhibitor of CREB-1 Memory suppressor gene Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC Sensitization – Long term 3- CREB-1 activates several immediate-response genes Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC 20  2024-10-23 Sensitization – Long term CREB-1 recruits 3- CREB-1 activates several coactivator CREB- immediate-response genes binding protein (CBP) to the promoter region. CBP (1) recruits RNA polymerase II and (2) facilitates transcription through its histone acetyltransferase activity Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC Sensitization – Long term 3- CREB-1 activates several immediate-response genes, including 4 - A ubiquitin hydrolase necessary for regulated proteolysis of the regulatory subunit of PKA. Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC 21  2024-10-23 Sensitization – Long term Cleavage of the (inhibitory) regulatory subunit results in persistent activity of PKA, leading to persistent phosphorylation of its substrate proteins ubiquitin hydrolase degradation Long-term training and induction of the ubiquitin hydrolase leads to degradation of approximately 25% of PKA regulatory subunits in the sensory neurons Mod. from Molecular Biology of the Cell (© Garland Science 2008) © Arruda Carvalho UTSC Sensitization – Long term Degradation of PKA Regulatory Subunits Triggers its Persistent Activity Aplysia ubiquitin carboxy- terminal hydrolase (Ap-uch) binds to the proteasome and increases its activity by assisting in the disassembly of ubiquitin chains Elevated cAMP levels + CREB-mediated transcription of Ap-uch Binding of cAMP = degradation of PKA R subunits leads to ubiquitination of R subunits Hedge and DiAntonio, Nat Rev Neuro 2002 © Arruda Carvalho UTSC 22  2024-10-23 Sensitization – Long term 3- CREB-1 activates several immediate-response genes, including 4 - A ubiquitin hydrolase necessary for regulated proteolysis of the regulatory subunit of PKA. Cleavage of the (inhibitory) regulatory subunit results in persistent activity of PKA, leading to persistent phosphorylation of the substrate proteins of PKA Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC Sensitization – Long Term 3- CREB-1 activates several immediate-response genes, including 5- CAAT box enhancer binding protein (C/EBP), which acts both as a homodimer and as a heterodimer with activating factor (AF) to activate downstream genes [including elongation factor 1a (EF1a)] that lead to the growth of new synaptic connections Kandel, Science, 2001 Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC 23  2024-10-23 Sensitization – Long term 3- CREB-1 activates several immediate-response genes, including C/EBP, which acts both as a homodimer and as a heterodimer with activating factor (AF) to activate downstream genes [including elongation factor 1a (EF1a)] that lead to the growth of new synaptic connections Kandel, Science, 2001 © Arruda Carvalho UTSC Sensitization – Long term Long-term structural changes of sensitization and habituation Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC 24  2024-10-23 Lecture Outline Implicit vs Explicit Memory Implicit Memory in Aplysia Habituation Sensitization Classical Conditioning Long-Term Facilitation PKA and CREB Synapse Specificity Dendritic Protein Synthesis CPEB Olfactory Conditioning in Drosophila Fear Conditioning in Mice © Arruda Carvalho © 2018 Arruda Carvalho UTSC winterUTSC term Is Facilitation Synapse-Specific? What’s in a memory? Where is information stored? © Arruda Carvalho UTSC 25  2024-10-23 Is Facilitation Synapse-Specific? Kelsey Martin © Arruda Carvalho UTSC Is Facilitation Synapse-Specific? Kandel, Science, 2001 Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC 26  2024-10-23 Is Facilitation Synapse-Specific? Both short-term and long-term synaptic facilitation are synapse specific and manifested only by the synapses that receive the serotonin treatment Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC Is Facilitation Synapse-Specific? How are specific synapses targeted by these nuclear products??? ? Newly synthesized proteins exclusively targeted to those synapses that receive serotonin ? Newly synthesized proteins present in all synapses but only used productively at those synapses that have been activated by serotonin Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC 27  2024-10-23 Is Facilitation Synapse-Specific? How are specific synapses targeted by these nuclear products??? Newly synthesized gene products are delivered to all the synapses of a neuron, but are only functionally incorporated at synapses that have been tagged/marked by previous synaptic activity Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC Is Facilitation Synapse-Specific? “Although one pulse of serotonin at a synapse is insufficient to turn on new gene expression in the cell body, it is sufficient to allow that synapse to make productive use of new proteins generated in the soma in response to the five pulses of serotonin at another synapse” Long-term, the function of a synapse is determined by (1) the history of usage of that synapse, and (2) by the state of the transcriptional machinery in the nucleus Once prolonged activity triggers the cascade of events we just discussed, only synapses tagged by activity (neurotransmitter pulse) will undergo facilitation synaptic capture or synaptic tagging What is the tag? © Arruda Carvalho UTSC 28  2024-10-23 Playing Tag Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC Lecture Outline Implicit vs Explicit Memory Implicit Memory in Aplysia Habituation Sensitization Classical Conditioning Long-Term Facilitation PKA and CREB Synapse Specificity Dendritic Protein Synthesis CPEB Olfactory Conditioning in Drosophila Fear Conditioning in Mice © Arruda Carvalho © 2018 Arruda Carvalho UTSC winterUTSC term 29  2024-10-23 Ribosomes are Present at the Synapse Steward and Levy, J Neurosci, 1982 The majority of the polyribosomes in dendrites are selectively positioned beneath postsynaptic sites © Arruda Carvalho UTSC Protein Synthesis in Mechanically Isolated Dendrites Protein synthesis reporter in which the coding sequence of green fluorescent protein is flanked by the 5' and 3' untranslated regions from CAMKII-alpha BDNF treatment in transected neuron Translation leads to GFP expression Aakalu et al., Neuron 2001 © Arruda Carvalho UTSC 30  2024-10-23 Is Dendritic Protein Synthesis Important for Long-term Facilitation? Maintenance of learning-induced synaptic growth requires new local protein synthesis at the synapse How is this regulated? Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC Lecture Outline Implicit vs Explicit Memory Implicit Memory in Aplysia Habituation Sensitization Classical Conditioning Long-Term Facilitation PKA and CREB Synapse Specificity Dendritic Protein Synthesis CPEB Olfactory Conditioning in Drosophila Fear Conditioning in Mice © Arruda Carvalho © 2018 Arruda Carvalho UTSC winterUTSC term 31  2024-10-23 Dendritic Protein Synthesis and Long-term Facilitation In Xenopus oocytes, the maternal mRNAs have a short poly(A) tail which renders them translationally dormant Synaptic stimulation induces phosphorylation of cytoplasmic polyadenylation element binding protein (CPEB), leading to recruitment of Poly(A) polymerase (PAP) which elongates the 3’ poly(A) tail, enabling dendritic translation of these mRNAs Mendez and Richter, Nat Rev Mol Biol, 2001 © Arruda Carvalho UTSC Dendritic Protein Synthesis and Long-term Facilitation In Xenopus oocytes, the maternal mRNAs have a short poly(A) tail which renders them translationally dormant Synaptic stimulation induces phosphorylation of cytoplasmic polyadenylation element binding protein (CPEB), leading to recruitment of Poly(A) polymerase (PAP) which elongates the 3’ poly(A) tail, enabling dendritic translation of these mRNAs Which mRNAs? Udagawa et al., Mol Cell 2012 © Arruda Carvalho UTSC 32  2024-10-23 Dendritic Protein Synthesis via CPEB Synaptic stimulation Phosphorylation of CPEB 3’ poly(a) tail elongation Dendritic translation of mRNAs Udagawa et al., Mol Cell 2012 © Arruda Carvalho UTSC Dendritic Protein Synthesis via CPEB Synaptic stimulation Phosphorylation of CPEB 3’ poly(a) tail elongation Dendritic translation of mRNAs Udagawa et al., Mol Cell 2012 © Arruda Carvalho UTSC 33  2024-10-23 Dendritic Protein Synthesis via CPEB Synaptic stimulation Phosphorylation of CPEB 3’ poly(a) tail elongation Dendritic translation of mRNAs Udagawa et al., Mol Cell 2012 © Arruda Carvalho UTSC 5-HT induces Dendritic CPEB Expression in Aplysia Sensory Neurons Si et al., Cell 2003 © Arruda Carvalho UTSC 34  2024-10-23 5-HT induction of Dendritic CPEB Expression in Aplysia Sensory Neurons Depends on PI3 Kinase A B C Aplysia pleural ganglia was treated for 30 min with PKA inhibitor KT5720 (A), PKC inhibitor Chelerython (B), or PI3 kinase inhibitor LY294002 (C) before stimulation with 5-HT for an hour. Si et al., Cell 2003 © Arruda Carvalho UTSC Local Inhibition of CPEB Blocks Stabilization of Long-Term Facilitation How does CPEB stabilize the long-term phase of LTF? Can it self-sustain? TAT-ApCPEB antisense oligo (TAT-AS) or TAT-scrambled oligo was perfused onto one of the branches for 30 min, and cells were stimulated by bath application of 5-HT. EPSPs were recorded in L7 motor Si et al., Cell 2003 neuron at 24 hr and 72 hr. © Arruda Carvalho UTSC 35  2024-10-23 Neuronal Isoform of Aplysia CPEB Displays Self-sustaining Properties Resembling Prion Proteins The switch between Aplysia CPEB inactive (soluble) conformational state and the active (aggregated) state depends on its N-terminal, glutamine- rich domain, similar to prion domains in other proteins. Electron micrograph of recombinant ApCPEB shows fibers similar to known amyloids. When sampled immediately after removal of the denaturant (0 hr) there is almost no fiber, but after 1 hr the fibers are clearly visible. Scale bar, 200 nm. Si et al., Cell 2010 © Arruda Carvalho UTSC 5-HT increases CPEB Expression Past Aggregation Threshold Schematic of the experimental design. Sensory neurons in the sensory-motor neuron coculture were injected with the indicated DNA and incubated for 2 days for expression to reach a steady-state level. Expressing cells were stimulated with 5 pulses of 5-HT, a protocol known to produce long- term facilitation of the sensory-motor neuron synapse and imaged at the indicated times. Aggregated, active state of CPEB activates the translation of dormant mRNAs Once the active state is established, it becomes self-perpetuating by recruiting soluble CPEB to aggregate Si et al., Cell 2010 © Arruda Carvalho UTSC 36  2024-10-23 CPEB: A Self-perpetuating, Self-sustaining, Synapse-specific Long-term Molecular Mechanism for Persistence of Memory Storage? Aplysia long term facilitation: 1. PKA, necessary for the immediate synaptic growth 2. PI3 kinase initiates the local translation of mRNAs required to maintain synaptic growth and long- term facilitation past 24 hours (e.g. CPEB) 3. Aggregated CPEB leads to local protein synthesis (e.g. N-actin and tubulin, which stabilize newly grown synaptic structures) Principles of Neural Science ©McGraw Hill © Arruda Carvalho UTSC Are these Mechanisms also Present in Other Species? Follow the Molecule… © Arruda Carvalho UTSC 37  2024-10-23 Lecture Outline Implicit vs Explicit Memory Implicit Memory in Aplysia Habituation Sensitization Classical Conditioning Long-Term Facilitation PKA and CREB Synapse Specificity Dendritic Protein Synthesis CPEB Olfactory Conditioning in Drosophila Fear Conditioning in Mice © Arruda Carvalho © 2018 Arruda Carvalho UTSC winterUTSC term Are these Mechanisms also Present in Other Species? Drosophila Melanogaster https://www.yourgenome.org/stories/fruit-flies-in-the-laboratory © Arruda Carvalho UTSC 38  2024-10-23 https://www.ua-magazine.com/wp-content/uploads/2015/02/procedure.jpg © Arruda Carvalho UTSC Many Learning Impaired Mutants Display Defects in the cAMP Cascade Davis, Annu Rev Neurosci 2005 © Arruda Carvalho UTSC 39  2024-10-23 PKA, CREB and Short and Long-term Memory “The activation of PKA leads to either the phosphorylation of a variety of substrates for the establishment of short- term memory or the phosphorylation of CREB for the establishment of long-term memory.” Davis, Annu Rev Neurosci 2005 © Arruda Carvalho UTSC CREB and Short and Long-term Memory (control) (CREB repressor) induction of CREB repressor gene disrupts long-term olfactory conditioning memory without affecting short-term memory Mod from Yin et al., Cell 1994 © Arruda Carvalho UTSC 40  2024-10-23 Lecture Outline Implicit vs Explicit Memory Implicit Memory in Aplysia Habituation Sensitization Classical Conditioning Long-Term Facilitation PKA and CREB Synapse Specificity Dendritic Protein Synthesis CPEB Olfactory Conditioning in Drosophila Fear Conditioning in Mice © Arruda Carvalho © 2018 Arruda Carvalho UTSC winterUTSC term Mice with Reduction in PKA Activity are Impaired in Fear Conditioning R(AB) = a mutant form of the regulatory subunit of PKA that inhibits its enzyme activity Kandel, Science 2001 © Arruda Carvalho UTSC 41  2024-10-23 Mice with Disrupted CREB Activity are Impaired in Long but not Short-term Fear Conditioning 30min 24h Mutants = Targeted disruption of two CREB isoforms Bourtchuladze et al., Cell 1994 © Arruda Carvalho UTSC Lecture Outline Implicit vs Explicit Memory Implicit Memory in Aplysia Habituation Sensitization Classical Conditioning Long-Term Facilitation PKA and CREB Synapse Specificity Dendritic Protein Synthesis CPEB Olfactory Conditioning in Drosophila Fear Conditioning in Mice © Arruda Carvalho © 2018 Arruda Carvalho UTSC winterUTSC term 42