Pharmacological Modulation of Memory Flashcards
What is memory?
the term given tot he process and structures involved in storage and subsequent retrieval of information
3 stages of memory
- Encoding: - sensory input is relayed into the brain (thalamus - processing centre) and is subsequently relayed into e.g., occipital lobe towards the visual cortex or amygdala for fear responses → determine how we will interpret that experience (i.e., if that information is attended to or not) SUBJECTIVE
- Storage: - associated with neural networks, in short term can be quite plastic → through rehearsal these memories are maintained - consolidates memory, which can lead to long term encoding which can be easily retrieved
- Retrieval
Explicit (Declarative) Memory
Facts, Events, People, Places and object
→ mainly mediated in the hippocampus
→ conscious attention is necessary for recall
Implicit (Procedural) Memory:
Unconsciously recalled
→ Skill & Habits: Striatum, affected in PD - affecting motor functions
→ Associative learning: Amygdala (Emotional response) & Cerebellum (Movement skills)
→ Non-associative learning: Habituation and sensitisation - reflex pathways which we can’t consciously control but can affect attention
What is meant by “Semantics”?
to make meaning of something - is it a good or bad memory - i.e., is it a good or bad experience, depending on the impact it made determines whether or not it gets processed into a longer term memory
Factors which can affect memory in a negative way
- Old age
- Stress
- ADHD
- Schizophrenia (Negative Symptoms)
- Anxiety/Depression
- Sleep Deprivation
How does electroshock therapy affect memory?
Has a serious negative impact on retrograde memory
ADHD is believed to be due to…
a lack of connection between neurons in the prefrontal cortex
Relay centre for memory storage
Hippocampus
How was learning and memory linked to the hippocampus?
Patient H.M.
→ intractable temporal lobe epilepsy. Bilateral removal of H.M.’s temporal lobe & hippocampus cured his epileptic seizures. Declarative memory was impaired. Procedural memory was intact.
Age-associated hippocampal atrophy corresponds to..
cognitive decline
Hebb’s Rule
Cells that fire together wire together (synaptic efficacy arises from presynaptic cell repeatedly stimulating postsynaptic cell)
A key aspect of memory depends on
Glutamate
NMDA glutamate receptor
-heteromeric ion channel
- 4 subunits (2x NR1, 2x NR2)
- glutmate binds NR2
- glycine (co-agonist) binds NR1
NMDA receptor antagonists
Memantine, Amantadine, Ketamine, PCP (angel dust)
Overactivation of glutamate receptors can induce
Excitotoxicity
