Unit 4, hippocampus and na, floh Flashcards
what is the major cell type in the dentate gyrus?
granule cells
cells in the inner 1/3 of the DG are innervated by the this type of fiber
mossy cells
mossy fibers in the Dg connect where?
to pyramidal cells in CA3
what is special about the mossy fiber/CA3 connection?
sparse, but potent; 1:14
what connections come into the DG outer 1/3?
connections from the entorhinal cortex, perforant path
is the dG “in the slice?”
yes! spread is less than 400 um
what kind of cell is in the hillus and what nt?
glutamatergic mossy cells
where are mc of the hillus connecting?
to granule cells of the DG
are hillus cells in the slice?
no, project contra too, via associational commisural fibers
what fourthings innervate ca3 cells?
dg, recurrent collaterals in ca3, peprofrant path and interneurons
what is the connections of ca3 with ca1 called?
projection via chaffer collaerals
what is unique about CA3 septo-temporal spread?
very large! talks to everybody; 7mm!!
CA1 has compact information, simlar to area
DG
where do the pyramidal cells in ca1 go?
project to subicular cells
what is the major projection of the subiculum?
out of the hipp, to the cortex, + interneurons
what is the role of interneurons in the hippocampus (DG)?
layer, input specific, GABA, few, but can shunt Glut
what are three subcortical inputs to the hippocapus?
amygdala, septum, thalamus
what are efferents of the subiculum?
thalamus, amygdala, hypothalams, nA
what is the role of the hippocampus:
declarative memory. HM, profound anterograde amnesia, probs in declarative mem. consolidation and temporary storage of
two tests that would help determine cognative memory in tact in an amnesiac
stem completion and percepual id
two non-declaritive tasks that hm is good at:
drawing looking at a mirror, and weather prediction
hm cannot do these declaritive tasks
paired assc, draw from memory, story recall.
one problem with the slice prep
most intrhippoampal projections cover a substantial spread
what is the main function of mossy cells:
mediate communication between dg cells along the axis
do CA1 cells talk to each other?
no!
what are the major input stations to the hipp
ca1 and the dg
what is the main function of interneurons
synchronized, rhythmic activity
what is the major subcortical input and output region
septum
what is the main nueron type in the NA/
MSN, gabageric ach or gaba inter
in a sentence, what is the function of the na?
sensory motor integration
why is the core “more motor?”
because it recieves input form substantia nigra
why is shell more limbic?
recieves VTA
evidence that na are involved in motivation
cells that change their firing rate when presented with an appetitive or aversive stimuli
what is a typical “core’ coding of rewared?
cue, lots of firing, until reward is presented, fire again.
how is drug addiction coded in na?
increased da, more firing
