• Disorders of memory

• Quiz 4, review Exam 3 next Tuesday
• Exam 4, Thursday, December 17, 6:50 PM - 8:40 PM

• Learning and memory involve changes in neural firing, circuitry
• Hebbian learning a type of associative learning
• NMDA receptor as coincidence detector
  • Molecular basis of one form of long-term potentiation (LTP)
• Different types of information stored in different brain systems

• Intractable/untreatable epilepsy
• Bilateral resection of medial temporal lobe (1953)
• Epilepsy now treatable
• But, memory impaired
• Lived until 2008

• Acquired loss of memory
• ≠ normal forgetting
• Note: computers don’t forget

• Retrograde amnesia
  • Can’t remember 10 yrs before operation
  • Distant past better than more recent
• Severe, global anterograde amnesia
  • Impaired learning of new facts, events, people
• But, skills (mirror learning) intact

• Retrograde (‘backwards’ in time)
  • Damage to information acquired pre-injury
  • Temporally graded
• Anterograde (‘forward’ in time)
  • Damage to information acquired/experienced post-injury

Every day is alone in itself, whatever enjoyment I’ve had, and whatever sorrow I’ve had…Right now, I’m wondering, have I done or said anything amiss? You see at this moment, everything looks clear to me, but what happened just before? That’s what worries me. It’s like waking from a dream. I just don’t remember.

• Disease
  • Alzheimer’s, herpes virus
• Korsakoff’s syndrome
  • Result of severe alcoholism
  • Impairs medial thalamus & mammillary bodies

• Fencing accident
• Damage to medial thalamus
• Anterograde + graded retrograde amnesia
• Are thalamus & medial temporal region connected?

• Skill-learning
• Mirror-reading, writing
• Short-term memory
• “Cognitive” skills
• Priming

• Long-term memory for facts, events, people
• ≠ Short-term memory
• ≠ Long-term memory for “skills”
• Separate memory systems in the brain?

• Chronic, neurodegenerative disease affecting ~5 M Americans
• Cognitive dysfunction (memory loss, language difficulties, planning, coordination)
• Psychiatric symptoms and behavioral disturbances
• Difficulties with daily living
• (Burns & Iliffe, 2009)

• Post-mortem exams show \(\beta\) amyloid plaques and neurofibrillary tangles in hippocampus + other brain areas

• Acetylcholinesterase (AChE) inhbitors (e.g. Aricept)
• NMDA-R partial antagonists (e.g., Memantine)
• Drugs that address amyloid \(\beta\) don’t work especially well
• AD the result of disordered immune response?

• Dense in NMDA receptors
• Formation, storage, consolidation of long-term episodic or declarative memories
• Stores info for later transfer to cortex
  • “Engrams” form in hipp & PFC simultaneously, fade in PFC over time

• Place cells
• Grid cells
• Head-direction cells