Neuroanatomy: Block 3, # 33 - Hippocampus And Amygdala

Front 1

what's papez's limbic circuit, starting at the hipocampus?

Back 1

hipicampus to fornix to mamillary bodies through mamilothalamic tract to the anterior nucleus of the thalamus to the cingulate gyrus to the parahipocampal gyrus to the hipocampus.

Front 2

what are the basic agreed upon functions of the limbic system?

Back 2

drive, arousal, emotional regulation, and encoding memories based on those emotions.

Front 3

where's the amygdla? how is it divided up and what do the parts do?

Back 3

in the temporal pole. note that its mass in the temporal lobe is pretty large and gives rise to the uncus bump.


divided into the corticomedian (olfaction), the central (autonomics), and the basloateral (emotioal attachments and memory formation).

Front 4

what about the cingulate gyrus? what does it connect to in the front and back and how is it divided?

Back 4

in the front, it blends into the subcalossal gyrus.

in the back, it blends into the parahipocampal gyrus.

Front 5

how is the hipocampus divdied?

Back 5

SD: the subiculum and the dentate gyri, and the hipocampus proper.

Front 6

how is the hipocampus proper divided?

Back 6

CA1 through CA4.

Front 7

how does information enter the hipocampus? how about get out?

Back 7

through the parahipocampal gyrus, at the back side and below the cingulate gyrus.

information synapses in the parahipocampal gyrus and then goes to the hipocampus.

main output is the fornix. but there are direct cortical connections. fibers in hipocampus synapse on parahipocampal formation, then project back to the cortex.

Front 8

functionally, talk more about what the amygdla does:

also, the septal nuclei:

Back 8

it attaches emotional value to stimuli, so we know how to respond. note that lesions to this area blunt that.

septal nuclei: stimulation feels great, not too well know what's up. lesions in humans have been shown to cause 'social stickiness' - inappropriate attachments.

note that cocaine also works here.

think of deviated septum from doing too much coke, and coked up people being too friendly.

Front 9

what is the cingulate all about functionally? what diseases are linked to it?

what about the hipocampus generally?

Back 9

connecting cognition and behavior.

linked to depression, tourett's. lesion = abulia (lack of drive).

hipocampus is important for memory - especially the emotional imprinting of memory

Front 10

what's kluver-busey syndrome?

Back 10

lesions of the amygdla. pick's disease is like this.

see decrease in aggression, less fear (to the point of danger), hyper sexuality, increased oral fixation.

Front 11

what happens if you lesion up the hipocampus?

Back 11

amnestic disorders! specificially, anterograde amnesia. can't learn new things.

keep old skills, remote memory preserved. don't necessarily remember learning these things.

Front 12

what's another disease associated with anterograde amnesia?

Back 12

korsakoff's syndrome - found in alcoholics and resultan thiamine deficiency. see leesions in the thalamus and the mamillary bodies. not sure exactly how this works.

Front 13

lesions of the anterior cingulum is associated with what?

Back 13

OCD, tourett's, depression. abulia (lack of drive)

Front 14

what's the cingulum pathway?

Back 14

white matter tract within the cingulate gyrus.

connects the front of the gyrus (subcalossal) with the posterior regions (parahipocampal and hipocampal). also connects up with the rest of the cortex.

Front 15

what all does the fornix interconnect?

Back 15

hipocampus with the mamillary bodies.

also, the basal forebrain, spetal areas, and thalamus.

Front 16

what about the lateral olfactory stria?

Back 16

olfactory bulb to the corticomedial side of the amygdla.

Front 17

how can drives be separated?

Back 17

primary or secondary, or...inaint or acquired.

primary/inaint = food, sex.

acquired/secondary = money and BMW's.

Front 18

what does the amygdla do?

Back 18

has 3 regions. the corticomedial is connected up with the olfactory bulb via the olfactory stria pathway.

the basolateral group has dense connections to the hipocampus and cortex. ATTACHES EMOTION TO MEMORIES/OBJECTS/LEARNING.

Front 19

what does cingulate gyrus do?

Back 19

link cognition to affect and behavior.

Front 20

what's going on in korsakoff's syndrome?

Back 20

EtOH often, lots of times it's thiamine deficiency. B1.

Lesion is probably midbrain - loose the thalamus, specifically the DM, mamillary bodies, periventricular gray.

clasically have anterograde amnesia, and some degree of retrograde amnesia too.