Memory Flashcards
retrograde amnesia
can form new memories but forget old ones (can be temporally graded - only remember childhood for ex.)
anterograde amnesia
can’t form new memories but remember old ones
patient HM
went through bilateral medial temporal lobectomy to treat epilepsy. anterograde amnesia, but working memory intact.
implicit memory
unconscious thought
explicit memory
can be actively recalled
memory consolidation
subtypes of explicit memory
episodic & semantic
Episodic memory
personally experienced events
Semantic memory
facts and general knowledge
long-term potentiation
memory at a cellular level; persistent strengthening of synapses in a neuronal network (the stronger the synapse, better the memory)
patient KC
where are implicit memories processed
cerebellum and basal ganglia
where are explicit memories processed
hippocampus, frontal and temporal lobes
hippocampal indexing theory
informations get indexed together in one spot in hippocampus. later only one needs to be triggered to generate recall of others. stronger connections are made.
lesion on hippocampus
dysfunction in consolidating new long-term memories
cell changes during LTP
large influx of glutamate binds to AMPA receptors, causing depolarization and telling magnesium that blocks NMDA receptors. glutamate then binds do NMDAr. high glutamate in cell causes more AMPAr to come to surface of membrane (positive feedback cycle)
functional changes during LTP
AMPA receptors recruited to membrane to allow for more signals to occur; lasts for a couple hours.
structural changes during LTP
early onset AD
familial or genetic
defining characteristics of AD
Brain volume decreases
Neurofibrillary tangles
Amyloid plaques
Neurofibrillary tangles
Hyperphosphorylated tau aggregates and axon disintegrates. Intracellular marker
Amyloid plaques
beta-amyloid proteins don’t break properly from APP and clump together forming plaques around the neuron. Extracellular marker
time course of AD
neurodegeneration is happening before symptoms. amyloid plaques starts to form, triggering neurofibrillary tangles at one point; neuronal integrity is decreasing.
AD biomarkers
through CSF: lower beta-amyloid, higher tau levels
