Learning and Memory Class Exam 3 Materials Learning and Memory Learning and Memory Topics Memory organization Types of learning memory Basal ganglia and S R habit learning Brain reinforcement circuits Hippocampus and Relational learning Human amnesia Synaptic plasticity long term potentiation LTP Learning Memory relatively permanent changes in behavior produced by experience Learning involves changes in the nervous system synaptic plasticity Forms of Learning Stimulus Response learning making a response when a particular stimulus is present S R habits Classical conditioning Pavlov Classical Conditioning Fear and Amygdala Classical Conditioning Eye blink Learning and Memory1 Forms of Learning Stimulus Response learning Operant conditioning Operant Conditioning Memory Organization Memory is organized in multiple brain systems The systems differ in terms of the type of memory they are involved in S R habit memory vs cognitive relational memory Basal Ganglia and S R Habits BG are Subcortical structures Learning and Memory2 S R habit learning involves the basal ganglia Examples Rats S R visual discrimination in radial maze Visible platform water maze task Response learning in plus maze Humans weather prediction task S R Radial Maze Task Illuminated maze arms contain food reward Lesions of basal ganglia impair learning S R Habit Water Maze Task Visible platform task Rats learn to swim to a visible escape platform Lesions of basal ganglia impair learning Response Learning in Plus Maze Rats are trained in plus maze to always make same body turn left Lesions of basal ganglia impair acquisition Learning and Memory3 S R Habit Weather Prediction Task Subject shown from 1 4 cards on screen Asked to predict rain or shine Subject told correct or incorrect on each trial Each cue is probabilistically associated with rain or shine S R Habit Weather Prediction Task Patients with basal ganglia damage Parkinson s disease are impaired in learning Basal Ganglia and Habit Learning Are these really learning and memory deficits Are these deficits selective to habit learning Use dissociation methodology Cognitive Radial Maze Task Single dissociation lesion of brain structure X impairs learning in task A but not task B Learning and Memory4 Each maze arm is baited once Rat learns to visit each arm only once to obtain food Lesions of basal ganglia DO NOT impair learning Cognitive Water Maze Task Hidden platform task Rats learn to swim to a hidden escape platform Platform is always in same spatial location Lesions of basal ganglia DO NOT impair learning Cognitive Place Learning in Plus Maze Rats are trained in plus maze to always approach the same spatial location Lesions of basal ganglia DO NOT impair acquisition Reinforcement Circuits Electrical stimulation of rat brain induces reward Olds study Responses that produce brain stimulation are repeated e g bar press alley running Dopamine plays a critical role in reinforcement Learning and Memory5 Mesolimbic dopamine system Nucleus Accumbens and Reinforcement Mesolimbic DA pathway Ventral tegmental area nucleus accumbens Rats self inject dopamine agonists into the nucleus accumbens Dopamine receptor antagonists interfere with reinforcement Microdialysis increased dopamine in nucleus accumbens produced by Drugs of abuse Natural reinforcers food sex Brain stimulation Learning and Memory6The Ventral Tegmental Area and the Nucleus Accumbens Diagrams of sections through a rat brain show the location of these regions Dopamine and Reinforcement Release of dopamine in the nucleus accumbens measured by microdialysis is produced Memory organization Memory is organized in multiple brain systems The systems differ in terms of the type of memory they are involved in Forms of Learning Cognitive Relational learning Spatial learning and navigation Hippocampus Relational Learning Relational cognitive learning involves the hippocampus Examples Rats win shift radial maze task Hidden platform water maze task Place learning in plus maze Cognitive Radial Maze Task Each maze arm is baited once Lesions of hippocampus impair learning Cognitive water maze task Learning and Memory7when a rat pressed a lever that delivered electrical stimulation to the ventral tegmental area Morris water maze rats must find hidden platform Hippocampal lesions impair learning Cognitive Place Learning in Plus Maze Rats are trained in plus maze to always approach the same spatial location Lesions of hippocampus impair learning Hippocampus and Cognitive Learning Are these deficits selective to cognitive learning Use dissociation methodology S R Radial Maze Task Illuminated maze arms contain food reward Lesions of hippocampus DO NOT impair learning S R Habit Water Maze Task Visible platform task Lesions of hippocampus DO NOT impair learning Response Learning in Plus Maze Rats are trained in plus maze to always make same body turn left Lesions of hippocampus DO NOT impair acquisition Learning and Memory8 Multiple Memory Systems Hippocampus and Basal Ganglia Double dissociation between memory function of hippocampus and basal ganglia Lesion of brain structure X impairs learning in task A but not task B Lesion of brain structure Y impairs learning in task B but not task A Hippocampal Place Cells Place cells Neurons in the hippocampus sensitive to the spatial location of a rat Firing rate of place cells varies with spatial location spatial receptive field Hippocampus Spatial Memory Human hippocampus is activated during tasks that require spatial navigation Dual Solution Plus Maze 1 Train rats Learning and Memory9Activity of a Hippocampal Place Cell The gray lines show the path a rat took exploring a square enclosure Red dots indicate the firing of a particular cell in the hippocampal formation As you can see this cell favored a particular location Activity of a Hippocampal Border Cell The firing rate of this cell is indicated by color hottest colors represent the highest rate of firing As you can see the cell fired preferentially when the animal was located along right border of the rectangular enclosure regardless of the dimensions of the enclosure 2 Inject with lidocaine or saline before probe trial in hippocampus or basal ganglia Lidocaine blocks sodium channels lesion 3 Assess use of place and response learning Dual solution plus maze task Probe trial Saline rats place learners Lidocaine basal ganglia place learners Lidocaine hippocampus Blocks place learning Second Probe trial Saline rats response learners