Transcript Paměť - Univerzita Karlova v Praze

Memory
ability
to accept information
to store
to recall, to retrieve information
from NS
•Memory vs learning
Engram
•Memory is not homogeneous
•Duration, persistence
•Brain structures
•Molecular mechanisms
Molecular mechanisms
• Posttetanic potentiation (short term
potentiation)
Long term potentiation LTP
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
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
Posttetanic potentiation
Large Ca2+ influx. Saturation
of the various Ca2+ buffering
systems (ER, mitochondia)
Temporary excess of Ca2+ is
called residual Ca2+.
Concentration of free Ca2+
affects the amount of
transmitter released
Long term potentiation LTP
NMDA – glutamate
receptor
Long term potentiation LTP
Glutamate synapse
Long term potentiation LTP
Increase in the
sensitivity and number
of postsynaptic AMPA
receptors
retrograde messenger
(NO)
Long term potentiation LTP
Presynaptic part
retrograde messenger
(nitric oxide)
Postsynaptic part
NO initiate an enhancement of transmitter release
that contributes to LTP
Long term potentiation LTP
Increase in the
sensitivity and number
of postsynaptic AMPA
receptors
retrograde messenger
(NO)
New synapses
Temporal phases of memory
(based on different biological mechanisms)
Iconic (visual) echoic (auditory) – reflect the activity of
sensory buffers, continuation of sensory neural activity
Short-term memories – last for seconds up to a minutes
Intermediate-term memory – for hours or days
Long-term memory – weeks, months, years, for the rest of the
life of an organism (permanent memory)
Working memory (short-term or intermediate-term) – is limited
by the use of information
Retrograde amnesia
A person who has been knocked unconscious selectively
loses memory for events that occured before the blow
This supports a model of
Memory storage in stages
A scheme of memory processes that includes
encoding, consolidation and retrieval
Long term memory
Pacient H.M.
H.M. was taught to trace between two outlines of a star
while viewing his hand in a mirror
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
Explicit memory is stored in association cortex
Explicit knowledge 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
Long term memory classification
Declarative
Explicit
Episodic
Store events
autobiograph
ical
Semantic
Nondeclarative
Implicit
Non
associative
Associative
learning
Epizodic-like memory test
Long term memory classification
Declarative
Explicit
Epizodic
Store events
autobiografic
Semantic
Store facts
Nondeclarative
Implicit
Non
associative
Associative
learning
Morris water maze
Blue velvet arena
Epizodic-like memory test
Long term memory classification
Declarative
Explicit
Epizodic
Store events
autobiografic
Semantic
Store facts
Habituation
Sensitization
Imprinting
Nondeclarative
Implicit
Nonassociative
No relation
between two or
more stimuli,
behavior and
its consequence
are not related
to.
Associative
learning
Long term memory
nondeclarative
nonassociateve
Habituation
Long term memory
nondeclarative
nonassociateve
Sensitization
Imprinting
Declarative
Explicit
Nondeclarative
Implicit
Long term memory
Epizodic
Store events
autobiografic
Semantic
Store facts
associative
learning –
neasociativní
relation between
stimulus-response
two or more
stimuli, events,
behavior – its
consequence
classical conditioning
instrumental, operant conditioning
(standard or motor learning)
conditioned taste aversion
priming
Classical conditioning
Ivan Petrovič Pavlov
Classical conditioning
Sir Charles Scott Sherrington
Standard operant conditioning
Standard operant conditioning
Priming
Priming
ABSENT
INCOME
FILLY
DISCUSS
CHEESE
ELEMENT
Priming
Priming (ovlivnění odhadu)
ABS
INC
FIL
DIS
CHE
ELE