Question | Answer |
When you lesion the limbic system do you still have short term memory? | yes |
What are the structures of the limbic system concerned with? | cognitive and visceral responses to emotion, processes involved with memory |
What are the structures belonging to the limbic system? | cingulate gyrus, hippocampus, amygdale, hypothalamus, mammillary bodies, anterior and medial thalamic nuclei |
Where is hippocampus? | temporal lobe deep to parahippocampal gyrus |
Where is the amygdala? | temporal lobe, deep to the uncus, anterior to hippocampus |
What is the purpose of Papez circuit? | permits a cognitive and visceral response to emotion, aids in putting info into long term memory |
State the Papez circuit: | info from neocortex or thalamus>cingulated gyrus>hippocampus and amygdale> project through fornix>mammilary bodies>medial and anterior thalamic nuclei>back to neocortex |
What is Korsakoff’s syndrome? | brain disorder caused by the lack of thiamine (vitamin B1) in the brain, can be caused by chronic alcoholism because alcohol messes with thiamine |
What are the 3 layers of the hippocampus? | striatum oriens = proximal axons, striatum pyramidal = somata, striatum radiatum = dendrites |
How are pyramidal cells in hippocampus arranged and how do they travel? | poly-synaptic loop ; axonal projections from entorhinal cortex to the dentate gyrus |
State the hippocampal circuitry: | entorhinal cortex>dentate gyrus>CA3(can go to fornix and to mammillary bodies)>CA1>subiculum>back to entorhinal cortex>associational neocortical areas |
In what layers of the hippocampus are GABAergic cells found? | in all layers |
Where the synaptic connections between are pyramidal cells most numerous? | hippocampus |
What is the function of hippocampus? | necessary for processing and storing explicit memory for long term storage |
What are the two classifications of memory? | explicit and implicit |
Does the hippocampus deal with implicit memory? | no |
What is implicit memory? | motor function, perceptual skills |
What is explicit memory? | factual knowledge like people places and things |
What is consolidation? | process done by the hippocampus necessary for converting short term to long term memory |
Is memory stored in the hippocampus? | no |
Where is memory stored? | cerebral cortex |
What is the result of damage to hippocampus or output circuits? | inability to form new longterm explicit memory but short term memory stays intact |
What happens when you get a hippocampus lesion on both sides? | loose ability to have space memories |
What happens when you get a hippocampus lesion on one side? | nothing |
What are space memories and where are space memories stored? | memories of where things are; hippocampus |
What are the two types of glutamate receptors and where are they found? | AMPA and NMDA receptors; post synaptic membrane of excitatory synapses |
What opens the AMPA receptors? | glutamate binding |
What opens NMDA receptors? | glutamate binding but only after signal from AMPA receptors |
Which is the small depolarization AMPA or NMDA? | AMPA |
What is the result of adding or removing AMPA receptors? | adding = learning, removing= unlearning |
When a synapse is made more functional what has it undergone? | LTP longterm potentiation |
When a synapse is made less functional what has it undergone? | LTD longterm depression |
How do you enhance synapses? | add AMPA receptors |
When does LTP occur? | after a burst of high frequency action potentials in the pre-synaptic neuron |
How do you reduce synapses efficiency? | remove AMPA receptors |
When does LTD occur? | after low frequency action potentials in pre-synaptic neuron |
Generation of new dendritic spines is an additional mechanism underlying what? | learning |
Why do axon spines protrude out and why do they occur? | to increase synaptic efficiency; LTP |
Where is the Amygdala located? | temporal lobe, deep to the uncus, anterior to hippocampus |
How is the Amygdala shaped? | like an almond |
What is the uncus? | a protrusion on the ventral surface of the brain caused by the Amygdala |
What does the Amygdala consist of? | a collection of neuronal nuclei |
What is the stria terminalis? | a pathway from the amygdala to the hypothalamus |
What do the efferents from the amygdala go to? | hypothalamus and cortical areas (particularly cingulated gyrus) |
What is the link between sensory stimuli and emotion? | Amygdala |
What mediates inborn and acquired emotional responses such as fear, anxiety, and sexuality? | Amygdala |
What is the result of stimulating the Amygdala? | anxiety and fear reactions along with physical responses (increase HR, increased respiration, papillary dilation |
How are autonomic responses mediated? | connectinos of Amygdala with hypothalamus |
How are conscious feelings mediated? | connections with cingulated gyrus and prefrontal cortex |
What is the result of bilateral lesions of the Amygdala? | placidity, flat affect; do not respond to threatening situations |
What is Hyperorality? | examine things with mouth |
What is Hypermetamorphosis? | compulsion to intensively explore immediate environment |
What is Kluver-bucy syndrome the result of? | bilateral damage to the Amygdala |
What are the symptoms of Kluver- Bucy syndrome? | hyperorality, hypermetamorphosis, placidity and fearlessness, hyperphagia, hypersexuality |
What is hyperphagia? | excessive eating, even when not hungry, may eat inappropriate objects |