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Memory Cellular and Molecular Basis of Memory Engram Temporal Types of Memory.

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Presentation on theme: "Memory Cellular and Molecular Basis of Memory Engram Temporal Types of Memory."— Presentation transcript:

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2 Memory Cellular and Molecular Basis of Memory Engram Temporal Types of Memory

3 Memory ability to accept information (encoding) to store (storage) to retrieve (retrieval) information from NS

4 Memory involves at least four distinct processes: Encoding - incoming information must be perceived Consolidation – newly stored information is labile, to make it more stable (expression of genes, structural changes Storage- to retain over time, almost unlimited capacity Retrieval – to bring different kinds of information together, it is constructive process, subject to distortion

5 Consolidation Retrograde amnesia A person who has been knocked unconscious selectively loses memory for events that occured before the blow

6 Retrieval recall (reproduction) - serial - free recall - cued record (with help, hint) (reproduction of paired associations) Recognition (to recognize again)

7 Memory vs learning Engram (print, foot-mark) Memory is not homogeneous Duration, persistence Brain structures Molecular mechanisms

8 Donald Olding Hebb *1904 †1985 Canadian psychologist Hebbian theory: When an axon of cell A is near enough to excite cell B and repeatedly or persistently takes part in firing it, some growth process or metabolic change takes place in one or both cells such that A's efficiency, as one of the cells firing B, is increased Hebb's Law. "Neurons that fire together wire together."

9 Eric Richard Kandel 1929 Vienna 2000 Nobel Prize in Physiology or Medicine The California sea slug (Aplysia californica) is also commonly called the California sea hare, and this is because the shape of all Aplysia species is reminiscent of the shape of a rabbit or hare. Sea hares are a kind of shell-less sea snail, a marine mollusk Experimental support for Hebbian learning

10 Molecular mechanisms Posttetanic potentiation (short term potentiation) Long term potentiation LTP

11 Posttetanic potentiation

12 Large Ca 2+ influx. Saturation of the various Ca 2+ buffering systems (ER, mitochondia) Temporary excess of Ca 2+ is called residual Ca 2+. Concentration of free Ca 2+ increases the amount of transmitter released

13 Posttetanic potentiation A hight rate of stimulation of the presynaptic neuron A gradual increase in the amplitude of the postsynaptic potential Postsynaptic potential increases in size = potentiation

14 Posttetanic potentiation The enhancement in the strength of the synapse represents storage of information about previous activity It can lasts minutes but can persist for an hour. An elementary form of memory

15 Long term potentiation LTP

16 NMDA – glutamate receptor

17 Glutamate receptors

18 Long term potentiation LTP Glutamate synapse Both NMDA and AMPA receptors

19 Increase the sensitivity Increase the number of postsynaptic AMPA receptors Long term potentiation LTP retrograde messenger (NO)

20 Long term potentiation LTP retrograde messenger (nitric oxide) Postsynaptic part Presynaptic part NO initiate an enhancement of transmitter release that contributes to LTP NMDA redeptor

21 New synapses Ca 2+ + calmodulin Transcription - mRNA Translation - proteins Long term potentiation LTP

22 New synapses Long term potentiation LTP retrograde messenger NO (enhancement of transmitter release ) Increase in the sensitivity and number of postsynaptic AMPA receptors

23 Temporal phases of memory (based on different biological mechanisms)

24 Iconic (visual) – reflect the activity of sensory buffers, continuation of sensory neural activity Short-term memories – last for seconds up to a minutes Long-term memory – weeks, months, years, for the rest of the life of an organism (permanent memory) Working memory (short-term plus activated long term memory)

25 A scheme of memory processes that includes encoding, consolidation and retrieval

26 Iconic (visual) echoic (auditory) – reflects the activity of sensory buffers, continuation of sensory neural activity Iconic memory (visual persistence, example burning ring) George Sperling 1960 In Sternberg R.J.: Kognitivní psychologie, Portál, Praha 2002: s Experiment: whole-report procedure Presentation 50 ms Recall of 3-5 symbols

27 Iconic (visual) George Sperling 1960 Experiment: partial-report procedure Presentation 50 ms Cued recall – The frequency of the tone (high, medium, or low) indicated which set of characters within the display were to be reported Recall of 9 symbols Sperling's original partial report paradigm Iconic memory is described as a very brief (<1000 ms), pre-categorical, high capacity memory store

28 Short-term memories last for seconds up to a minutes capacity 7 ± 2 items

29 Verbal memory AVLT Auditory Verbal Learning Test Remember folowing words

30 Verbal memory AVLT Who recall word table light bench pillow Dick 1. table 2. cloud 3. bookcase 4. tree 5. shirt 6. cat 7. light 8. dick 9. bench 10. chalk 11. flower 12. bat 13. blanket 14. soap 15. pillow

31 Verbal memory Ebinghaus curve order in series What is first What is fresh (last word)

32 Verbal memory Better memory for What concern you personally Personally interesting Unusual Connected with emotions erotic subtext

33 Comparison of verbal and visual memory

34 Explore each picture

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36 Write down names of things

37 Envelope Music Bird Brush Palette Tin Screwdriver Telephone Fireman Stairs Dustbin Bike Money Hen Lettuce Interactive image

38 Pacient H.M. Long term memory

39 H.M. was taught to trace between two outlines of a star while viewing his hand in a mirror

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41 Regions of the human brain that have been implicated in the formulation of long-term declarative memories. A lateral view of the brain shows the levels of the transverse sections Cross sections in two levels

42 Declarative Explicit Nondeclarative Implicit Episodic Store events autobiograph ical Semantic Non associative Associative learning Long term memory classification

43 Declarative Explicit Nondeclarative Implicit Episodic Store events autobiograph ical Semantic Non associative Associative learning Long term memory classification

44 Epizodic-like memory test

45 Declarative Explicit Nondeclarative Implicit Epizodic Store events autobiografic Semantic Store facts Non associative Associative learning Long term memory classification

46 Morris water maze

47 Temporal lobe lesion

48 Blue velvet arena

49 Test: Hidden goal in Blue velvet arena Alzheimer disease Control group Vascular dementia Mild cognitive impairment

50 Epizodic-like memory test

51 Declarative Explicit Nondeclarative Implicit Epizodic Store events autobiografic Semantic Store facts Non- associative No relation between two or more stimuli, behavior and its consequence are not related to. Associative learning Long term memory classification Habituation Sensitization Imprinting

52 Long term memory nonassociateve Habituation An animal responds less and less strongly to uniform gentle taps on its surface. Decreas in response to repeated stimulus

53 Long term memory nonassociateve Sensitization By a strong stimulation. A single electrical shock to the skin. Stronger reaction to the weak tap. Increas in response to repeated stimulus

54 Long term memory nonassociateve Imprinting

55 Konrad Lorenz Greylag geese incubator-hatched geese would imprint on the first suitable moving stimulus the goslings would imprint on Lorenz himself

56 Konrad Lorenz imprinted goslings Critical period

57 Declarative Explicit Nondeclarative Implicit Epizodic Store events autobiografic Semantic Store facts Non associative associative learning – relation between stimulus-response two or more stimuli, events, behavior – its consequence Long term memory classical conditioning instrumental, operant conditioning (standard or motor learning) conditioned taste aversion priming

58 Ivan Petrovič Pavlov Classical conditioning

59 Sir Charles Scott Sherrington Classical conditioning

60 Standard operant conditioning Edward Lee Thorndike ( )

61 Standard operant conditioning Skinner`s box

62 Priming

63 ABSENT INCOME FILLY DISCUSS CHEESE ELEMENT

64 Priming

65 ABS INC FIL DIS CHE ELE

66 Summary

67 Molecular level, synapses Posttetanic potentiation Long term potentiation

68 Declarative Explicit Nondeclarative Implicit Episodic Store events autobiograph ical Semantic Non associative Associative learning Iconic memory Short term memory Long term memory classification


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