Week8 Flashcards
memory
process(learning , imprinting)
store
retrieve information
Hebb (1949):
Short-term memory
Long-term memory
Baddeley & Hitch
working memory
Refers to the way we store information while
working on it
Korsakoff’s syndrome
thiamine deficiency (vitamin B1)
Alcoholics/anorexia
Confabulation
Alzheimer’s disease (AD)
Gradual increase in memory loss, confusion,
depression, restlessness, insomnia, and reduced
appetite
Patients with Down syndrome often develop AD by
middle age
Reduced
alertness
Causes of Alzheimer’s disease (AD)
Accumulation of amyloid-β in early onset AD.
o Damages axons and dendrites
o Reduces synaptic input
o Reduces plasticity
Neuronal degeneration
Damaged dendrites and axons cluster together in plaques
Cascade hypothesis
Large amounts of amyloid-β cause changes
in tau proteins, which then cannot bind to usual targets,
ultimately leading to tau buildup and tangles
Case H.M.
Underwent bilateral medial
temporal lobe resections
Hippocampus
- Delayed matching-to-sample task
- Delayed nonmatching-to-sample tasks
Hippocampal functions
+Recent memories with a lot of contextual detail
+Navigation and spatial orientation
-Older memories with less contextual details are more
dependent on the cerebral
cortex
Spatial memory
Hippocampus
* Place cells: That respond to a certain location
or when a route is planned
* Time cells: Coding for orientation in time
Entorhinal cortex
* Grid cells: Coding for a location in a hexagonal
grid
Weather prediction task depends on ?
This type of gradual, probabilistic learning depends
on the basal ganglia ( even if you do not remember the stragedy you get better.)
Hebbian synapse
increases in effectiveness because of
simultaneous activity in the presynaptic and postsynaptic neurons
* Such synapses may be critical for many kinds of associative learning
Long-term potentiation
occurs when one or more axons
bombard a dendrite with stimulation, and leaves the synapse
“potentiated” for a period of time making the neuron more
responsive
Long-term potentiation (LTP) types
o Specificity: only synapses onto a cell that have been highly active become strengthened
o **Cooperativity: **simultaneous stimulation via two or more axons produces LTP much more strongly than does repeated stimulation by a single axon
o Associativity: pairing a weak input with a strong input
enhances later responses to a weak input
Long-term depression (LTD)
A prolonged reduction in responsivity at a synapse,
that occurs when certain axons have ben less active
than others
* Compensatory process: as one synapse strengthens,
another weakens
* Else we would keep on using more energy for every
new thing that we learn!
IQ mainly correlates with?
grey matter surface
Lateralization
o The corpus callosum
o The anterior commissure
o The hippocampal commissure
o A few other small commissures
Treating epilepsy
Resection of regions with epileptic activity
cutting the corpus callosum
Split-brain patients
Maintain normal intellect and motivation
* Still able to walk and talk
* Have a new acquired ability to use the hands independently
in a way others find difficult
William’s syndrome
intellectual disability, but a skillful use of language
Deletion of several genes from chromosome 7
* Leads to decreased gray matter, especially in visual
processing areas
Inattentional blindness
hizli degisen resimlerdeki farki anlayamama
Spatial neglect
Tendency to ignore the left side of the body and
its surroundings or the left side of objects
* Often associated with damage to the right
hemisphere of the brain
* Effects are most pronounced after a stroke
Problems of neglect are associated with attention
and not sensation(goruyorlar ama cizemiyorlar)
LTP in hippocampal neurons occurs as follows
- Repeated glutamate excitation of AMPA receptors depolarizes the
membrane. - The depolarization removes magnesium ions that were blocking NMDA receptors.
- Glutamate can then excite the NMDA receptors, opening a channel for
calcium ions to enter the neuron.
How do AMPA and NMDA synapses differ
They respond differently to certain drugs.
