4: normal aging 3 Flashcards
if LTP is a neural analogue of learning/memory then: learning should elicit? artificial LTP should?
learning should elicit an LTP-like change in the brain. artificial LTP should interfere with normal learning/induce false memories.
if LTP is a neural analogue of learning/memory then: saturation of LTP should? blockade of LTP should? reversal of LTP should?
saturation: prevent learning, interfere with previous memories. blockade: prevent learning, won’t interfere with previous memories. reversal: erase previous memories
if LTP is a neural analogue of learning/memory then: aging effects on LTP?
should parallel aging effects on hippocampal dependent, spatial, learning and memory tasks
place cells
cells which show increased firing rates when animal is in a specific location
place fields: formation? stabilitiy? depends on? aged rats?
formation is rapid, requires experience to become stable. NMDA-R dependent (LTP like process maybe). Aged rats have unstable place fields
place fields are locked to?
geographical features. ex: rotate cylinder with spatial cues, the place cell firing rotates too
place cells are specific?
context/environment specific. ex: circular vs. triangular environments
place fields and stability?
place fields exhibit stability in the same environments. ex: recording over days/weeks, the existing place field is stable
elderly rats and place field experiment
unstable place fields in elderly rats across (but not within) sessions in given environment
place fields and goals?
4 arm radial maze: place field activity corresponds to rat’s selected goal arm
when rats travel repeatedly on given path, what happens to place fields? reflects?
place fields expand: could reflect an LTP-like association between sequentially activated place cells, might be a network mechanism for stable place field formation
place field expansion: what direction? depends on? older rats?
always in the direction opposite to travel (aka backwards). NMDA-R dependent. older rats show less place field expansion
summary: main changes in physiology (2) and plasticity (2) with aging
decreased synaptic response, calcium dysregulation which lead to impaired LTP and enhanced LTD
summary: main changes in network dynamics and aging (2)
no place field expansion (so less spatial info, impaired sequence encoding). poor binding of cues to hippocampal map (incorrect retrieval, delayed realignment to visual cues, impaired context encoding)
