46 - NA Limbic

Question 1

Limbic System

Answer 1

Limbic Association Cortex
Hippocampal Formation
Amygdala
Septal Nuclei & Basal Forebrain
Mesolimbic Dopaminergic System

Question 2

Mesolimbic Dopaminergic System

Answer 2

PAG, Midbrain Raphe, VTA - Pathology of this system may be linked with schizophrenia

Question 3

Limbic Association Cortex

Answer 3

Cingulate Gyrus
Parahippocampal Gyrus (especially Entorhinal Cortex)
Medial-Orbitofrontal Cortex
Temporal Pole (Anxiety)

Question 4

Hippocampal Formation

Answer 4

Hippocampus Proper
Dentate Gyrus
Subiculum
(And Entorhinal Cortex)

Question 5

Amygdala

Answer 5

Emotions, behaviors, mostly fear

Basolateral (Emotion)
Corticomedial (Neuroendocrine/Olfaction)
Central (Autonomic/Neuroendocrine)

Question 6

Somatic motor expression of emotions

Answer 6

Hypothalamus
Central or Corticomedial
OR
Ventral Striatum

Question 7

Papez Circuit

Answer 7

Cingulate Gyrus
Parahippocampal Gyrus
Hippocampus
Fornix
Mammilary bodies
Mammilothalamic Tract
Anterior Nucleus
Cingulate Gyrus

Question 8

HM

Answer 8

Hippocampal formation converts short term memories into long term memories. If it is excised, bitch can’t remember

Question 9

Septal Nuclei

Answer 9

Medial & Lateral
Lateral to Septum pellucidum
Magnocellular cholinergic cells
Project via ascending fornix to hippocampus & Medial Limbic Cortex

Question 10

Basal Forebrain

Answer 10

Ventral to Anterior Commissure
Rostral to Diencephalon
Cholinergic neurons project to lateral neocortex
Alzheimer Disease - Degeneration in basal forebrain region and reduction of ACH Transferase in cortical areas

Question 11

Amygdala

Answer 11

Corticomedial Nucleus
Processes olfactory inputs and emotion from basolateral nuclear group
Projects to hypothalamus, neuroendocrine
Basolateral and Central - processing and responding to fearful stimuli
Convergence of fearful stimuli in basolateral projects to central via medial forebrain bundle for appropriate behavior
Central nucleus to dorsal motor nucleus of X affecting visceral responses

Question 12

Outputs from the Amygdala

Answer 12

Stria Terminalis

Ventral Amygdofugal Pathway

Question 13

Stria Terminalis

Answer 13

Corticomedial Nucleus
C-Shaped
Exits from caudal end of amygdala
Terminates in hypothalamus

Bed nucleus receives input from all nuclei of amygdala, projects widespread to rest of limbic system

Question 14

Ventral Amygdalofugal Pathway

Answer 14

Basolateral N & Central N medially from amygdala to basal forebrain (nucleus basalis), medial dorsal nucleus (MD) of thalamus and through MFB to brainstem targets (dorsal motor nucleus of X)

Question 15

Fornix

Answer 15

C-Shaped Structure
Major efferent pathway of hippocampal formation.
Axons from cells in the subiculum and hippocampus
Alveus - Axons running on floor or lateral ventricle
Fimbria - beginning of fornix
Crus - Arch
Body - Ventral to corpus callosum
Column - Descends toward anterior commissure

Question 16

Postcommissural fornix

Answer 16

From subiculum

To Medial Nucleus of ipsilateral Mammillary body

Question 17

Precommissural fornix

Answer 17

From hippocampus proper

To septal area

Question 18

Lesion of the Mammillary Body

Answer 18

No endocrine or visceral deficits. ONLY MEMORY

Question 19

Entorhinal Parahippocampal Gyrus - HOW MANY LAYERS?!?!?!!?!?

Answer 19

6

Question 20

Hippocampus Proper & Dentate Gyrus - HOW MANY LAYERS?!?!?!?!?!!?!?!?

Answer 20

3

Question 21

Hippocampus - Input

Answer 21

Entorhinal Cortex
Amygdala
Septal Nuclei
Basal Forebrain

Question 22

Hippocampus - Output

Answer 22

Reciprocal to areas projecting to it

Plus Mammillary Bodies

Question 23

Perforant Pathway

Answer 23

Major input from entorhinal cortex
Activate granule cells in dentate gyrus.
Mossy fibers from dentate gyrus synapse on pyramidal cells in CA3 region.
CA3 Pyramidal cells synapse on CA1 Pyramidal cells, projecting to subiculum or fornix.
Pyramidal neurons in the subiculum project back to entorhinal cortex or fornix.
Disruption of synaptic functions in this pathway disrupts certain forms of long term memory.