Psyc 2012 1st Edition Lecture 11 Outline of Last Lecture I. Learning, Memory, and Synaptic Plasticity IA. Today’s lecture goalII. Learning and MemoryA. LearningB. MemoryC. Stages of memoryi. Encodingii. Consolidationiii. Storageiv. Recall/retrievalD. Types of memoryi. Very short term ii. Short term (STM)iii. Long term (LTM)iv. Explicit/declarativev. Implicit/proceduralIII. Neuroanatomy and MemoryA. Key pointB. Brain regions involved in explicit memoryi. Basal forebrainii. Prefrontal cortexiii. Medial temporal cortexiv. Hippocampusv. Rest of cortexC. Brain regions involved in implicit memoryi. Premotor cortexii. Motor cortexiii. Basal ganglia and cerebellumIV. Learning, synaptic transmission and synaptic plasticityA. Synaptic transmissionB. Synaptic plasticityC. Key pointD. Mechanisms of synaptic plasticityi. Changes in the strength of synaptic transmission at existing synapsesii. Changes in the number of synaptic connections between neuronsThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.iii. Changes in the number of neurons and therefore synaptic connections between neuronsE. Synaptic plasticity and memoryi. Very STM and STMii. LTMV. HabituationA. Studying habituation- Aplysia CalifornicaB. How does habituation happen on the neuron level?i. Normal synaptic transmissionii. Habituated synaptic transmissionVI.Outline of Current Lecture II. Learning and Longer-Term Synaptic PlasticityA. Today’s lecture goalIII. Ways Our Brains ChangeA. HabituationB. In LTM we see…IV. STMV. Long Term Potentiation (LTP)A. Key pointB. Late LTPC. LTP & Long-term memoryD. LTPi. Long term depression1. Early depressionVI. LTM- new synapse formation and neurogenesisA. Key pointB. 2 main ways to increase synaptic number in long-term memoryi. Synaptogenesisii. Neurogenesis1. Synaptogenesis requires extensive gene expressionC. Adult neurogenesisVII. Defects in memoryA. Amnesiai. Types of amnesia1. Retrograde amnesia2. Anterograde amnesiaii. Some causes of explicit memory amnesiaiii. Some causes of implicit memory amnesiaCurrent LectureWeek 6- Lecture 11- 2/19Learning and Longer-Term Synaptic PlasticityGoal: to learn how changes in synaptic transmission and synapse number contribute to consolidation and storage of memory.Ways Our Brains change- all of which can be increases or decreasesHabituation: temporary changes in the strength of synaptic transmission that don’t require new gene expression. In LTM we see…Longer-term change sin the strength of synaptic transmission that do require gene expressionChanges in the number of synaptic connections between neurons which requires new gene expressionFor the midterm, know which of these processes requires gene expression. (Habituation= no gene expression, LTM= requires gene expression)STMLasts minutes, to hours, to daysRepetition seems to increase the strength of duration of shot-term memory; the more you’re exposed to something, the more likely it will transfer into longer-term memory. Ex- studying for a biopsych examLong Term Potentiation (LTP): a longer lasting increase in the strength of the synaptic connection and the size of the post-synaptic potential, requiring new gene expression, in response to repeated activation of a synapse. This is associated with STMKey point- repeated synaptic transmission tends to increase the stability of the memory;this is a major part of LTP. Late LTP: the natural extension of early LTP; repeated activation causes protein synthesis, which leads to further expansion of the neuron and a stronger connection. This means longer-term memory and long-increases (or decreases) in synaptic transmission. Early LTP is the persistent activation of neurons, where changes occur more quickly but don’t last as long. LTP & Long-Term MemoryIn response to repeated activation, elevated Ca2+ levels activate a parade of signals in the post-synaptic neuron. This involves changes to existing synapses, rather than crating new ones. These signals ultimately turn on genes in the nucleus and produce new NT receptors, which are added to the dendrites on the post-synaptic neuron. More receptors means more NT binding, more ion channel opening, and a greater PSP size. PSP = post-synaptic potential (neurons communicating with each other). As you repeatedly stimulate the synapse, the connection gradually gets stronger. Calcium is higher outside the cell, so it wants to flood in. The opposite can happen too; we lose NT receptors if we don’t strengthen these synaptic connections, which basically means losing memory. Ex- Repeatedly seeing one number reinforces amount that the brain sends that # to the memory, which strengthens connections btwn synapses. This is a slow process due to Calcium build, but it also takes a while to break down. LTPLate LTP lasts longer than habituation or early LTP; usually hours, days or even months.We change the behavior of neurons by increasing the responsiveness of the post-synaptic cell, which is done by changing the strength of synaptic transmission. The learning here involves the increased likelihood of firing of neurons in the prefrontal and medial temporal cortex associated with the knowledge we are trying to learn, and the memory of this is “stored” in the greater number of NT receptors and greater responsiveness of the post-synaptic neurons. Basically, the prefrontal and medial temporal cortexes are where learning happens in this caseWe retain this learning in the changes to NT and responsiveness of neurons. The more often we activate these neurons, the more we maintain this increased synaptic transmission and the more likely we’ll be able to remember the info for longerIf we stop activating these neurons, over time the number of receptors may decrease and the post-synaptic neuron will respond normally to a new stimulus and we’ll “forget” particular thingsLong term depression- the suppression of neuronal activation and gene expression, which causes a smaller than normal response to the same stimulus; the opposite of LTP Early depression- the suppression of neuronal acitvationLTM- new synapse formation and neurogenesisOnce we strengthen a synapse to it’s fullest extent, it’s forced to branch out and create anew connection. This is when LTM happens instead of LTP. Can last days, months, years, or decadesEx- personal memories, facts learned in school , how to ride a bike, how to type,