Usu Neuro: 7 Olfactory And Limbic Systems

Front 1

Olfactory nerves are the axons of ________ neurons.

Back 1

Olfactory nerves are the axons of BIPOLAR neurons.

Front 2

Where are the cell bodies of olfactory nerves found?

Back 2

The cell bodies are found in the OLFACTORY MUCOSA.

Front 3

How many olfactory receptor types are found in each bipolar neuron?

Back 3

Each bipolar neuron has only one type of olfactory receptor.

Each receptor can respond to a range of molecules.

Front 4

Axons of the Olfactory Nerve (CN 1) terminate in the:

Back 4

Olfactory Bulb

Axons of the olfactory nerve located in the nasal septum course through the cribiform plate to terminate on mitral cells in the OLFACTORY BULB

Front 5

What type of cells carry olfactory information from the olfctory bulb to the brain?

Back 5

MITRAL CELLS

Axons of the olfactory nerve located in the nasal septum course through the cribiform plate to terminate on MITRAL CELLS in the Olfactory bulb.

Front 6

Where do collaterals of mitral cell axons synpase?

Back 6

Anterior Olfactory Nucleus (AON)

Front 7

Anterior Olfactory Nucleus (AON) Neuronsexit the olfactory tract via the:

Back 7

Medial Olfactory Stria

The axons then course through the Anterior White Commisure to end in the A.O.N. of the contralateral olfactory bulb.

Front 8

How do Mitral cells innervate structures in the CNS?

Back 8

Mitral cells send axons in the olfactory tract, through the lateral olfactory stria.

Front 9

What two CNS structures do mitral cells project to?

Back 9

1. Olfactory cortex
2. Amygdala

Front 10

The olfactory cortex is composed of two structures:

Back 10

Olfcatory Cortex:

1. Pyriform Lobe
2. Entorhinal cortex

NOTE: olfactory info projects to the cortex without synapsing in the thalamus.

Front 11

Primary olfactory cortex and the amygdala project olfactory information to the ____.

Back 11

Primary olfactory cortex and the amygdala project olfactory information to the DORSOMEDIAL THALAMIC Nucleus (DM)

(!! Mears initials!)

Front 12

Loss of olfactory function is an early sign of:

Back 12

Neuropathological diseases (Parkinson’s, Alzheimer’s)

Front 13

The complex genetic disorder causing a lack of a sense of smell is known as:

Back 13

Kallmann Syndrome

Front 14

There is a clinical association between Kallman syndrome and:

Back 14

Reproductive Function
- Low levels of reproductive hormones

Front 15

Lesions to what organ can cause male rats to lose interest in mating (most likely because they can’t detect pheromones)?

Back 15

Vomeronasal Organ
(aka Jacobsen's Organ)

Front 16

The limbic system is involved with what human functions:

Back 16

1. Homeostasis
2. Olfaction
3. Memory
4. Emotions

HOME !!

Front 17

Specifically, what does the limbic system do?

Back 17

The limbic system integrates information about the environment with the autonomic nervous system

Front 18

The structures that make up the limbic system are:

Back 18

1. Limbic lobe:
-Cingulate Gyrus
-Subcallosal Gyrus
-Parahippocampal Gyrus

2.Subcortical Centers
-Amygdala
-Septal Nuclei
-Basal Forebrain

3. Diencephalic Nuclei
-Anterior Thalamus
-Mammaillary Bodies

Front 19

What type of information does the Hippocampus receive?

Back 19

The Dentate Gyrus is the major INPUT zone for the Hippocampus

Front 20

What are the three layers of the Entorhinal cortex

Back 20

1. Outer Molecular Layer
2. Intermediate cell layer
3. Inner polymorphic layer

Front 21

What does the Intermediate layer of the Entorhinal cortex contain?

Back 21

Small Granule Cells

Front 22

Describe the projects of the small Ganule cells in the intermidiate layer of the Entorhinal cortex.

Back 22

Small Granule cells dendrites:
Radiate into the molecular layer

Small Granule cell axons:
Travel through the polymorphic layer to synapse on neurons in Hippocampus proper.

Front 23

Neurons in the Hippocampus proper receive inout from three sources. They are:

Back 23

1. Dentate Gyrus
2. Entorphinal cortex
3. Septum

Front 24

The three layers of the Hippocampus proper are:

Back 24

1. Outer Molecular layer
2. Intermediate cell layer
3. Inner Polymorphic cell layer

Front 25

The Intermediate layer of the Hippocampus contains Pyramidal cells who receive input from their dendrites in the molecular layer. Where do their axons go?

Back 25

Pyramidal cell axons synapse in the nearby Subiculum or enter the Fornix and terminate in the Septum

Front 26

What is the function of the Subiculum?

Back 26

The Subiculum is the MAJOR OUTPUT zone of the hippocampus

Front 27

Where do the axons of Pyramid cells in the subiculum go?

Back 27

Subiculum --> Alveus --> Fimbria --> Fornix

Most Pyramidal axons in the Subiculum form a sheet of axons called the ALVEUS that accumulated to form the FIMBRIA which forms the FORNIX.

Front 28

Where does the Fornix get its fibers from?

Back 28

The Hippocampus AND the subiculum

(Mostly from the SUBICULUM)

Front 29

What does the Hippocampus do with the highly processed info it receives from the association cortex via the entorhinal cortex?

Back 29

The Hippocampus converts short-term memory into long-term memory

Front 30

What is the ability of Hippocampal calls to remember called?

Back 30

LTP: Long-term potentiation

Front 31

Lesions to the Hippocampus result in a disorder called:

Back 31

Anterograde Amnesia

Front 32

What brain region is gorssly atrophied in patients with Alzheimer's disease?

Back 32

Entorhinal cortex

Front 33

What are the three structures that makes up the limbic lobe?

Back 33

1. Cingulate
2. Subcortical Centers
3. Dienchephalic Nuclei

Front 34

The dentate gyrus receives most of its information from the:

Back 34

The dentate gyrus receives most of its information from the ENTORHINAL CORTEX.

Front 35

The Hippocampus formation is made up of three regions:

Back 35

The Hippocampus formation is made up of three regions:

1. Dentate Gyrus
2. Hippocampus Proper
3. Subiculum

Front 36

Axons of the FORNIX course:

Precommissural Fornix:

Postcommissural Fornix

Back 36

Axons of the Fornx course:

1. Rostral to the Ant. Commissure (precommissural) ending in the SEPTUM

2. Caudal to the Ant.Commissure to the MAMMILLARY bodies and ANTERIOR Nucleus of the THALAMUS

Front 37

Where do precommissural fibers from the fornix course?

Back 37

Precommissural fibers of the fornix course:

Rostral to the Ant.Commissure ending in the septum

Front 38

Where do postcommissural fibers from the fornix course?

Back 38

Where do postcommissural fibers from the fornix course:

Caudal to the Ant.Commissure to the mammillary bodies and anterior nucleus of the thalamus.

Front 39

Emotional expression has been linked to a circut:

Back 39

The PAPEZ CIRCUT!

Cingulate Cortex --> Hippocampus --> Mammillary Bodies --> Anterior Thalamus --> Cingulate Cortex.... (REPEAT)

Front 40

Insults to the Papex Circut are suspect in which disease?

Back 40

Korsakoff Synrome

-Characterized by memory deficits, confabulation and confusion

Front 41

Define: Korsakoff Syndrome

Causes?

Back 41

Korsakoff Syndrome: insults to the Papez Circut; particularly the Mammillary Bodies, Anterior/DM Thalamus Nuclei

Charterized by memory deficits, confabulation, and confusion

Caused by Thiamine deficiency in alcoholism.

Front 42

What is the function of the SEPTUM?

Back 42

Septal activity labels sensory stimuli as PLEASURABLE or POSITIVE

Front 43

What are the inputs to the Septal Nuclei?

Back 43

1. Hippocampus
- Via the fornix

2. Hypothalamus and Midbrain
-via the medial forebrain bundle

3. Amygdala
-via the amydalofugal pathway and stria terminalis

Front 44

What are the efferent tracts of the Septal nuclei?

Back 44

1. Hippocampus
-via the fornix

2. Hypothalamus and midbrain
-via the medial forebrain bundle (MFB)

3. Habenua
-via the stria medullaris thalami

Front 45

Lesions to the Septal Nuclei produce what effects?

Back 45

1. Hyperemotional States

2. Impaired learning

Front 46

What structure is thought to mediate pleasure, especially with addictive drugs?

Back 46

Nucleus Accumbens Septi

Location: Ventral striatum, at a junction of head of caudate and the putamen.

Front 47

Two main functions of the Amygdala include:

Back 47

1. Focusing Attention

2. Labeling stimuli as NEGATIVE or HARMFUL

Front 48

Stimulation of the Amygdala produces:

Back 48

Initial stimulation: Arrest reactions (stops what it is doing, scans environment)

Continued stimulation: Fight or Fligth

Front 49

What structures input into the Amygdala:

Back 49

1. Temporal Lobe
2. DIRECT OLFACTORY (!) information
3. Limbic and autonomic structures

Hearing, Smell, Emotion!!

Front 50

What are the output tracts of the Amygdala?

Back 50

1. STRIA TERMINALIS: Septal region and hypothalamus

2. Ventral AMYGDALOFUGAL tract to:
PAG, Autonomic centers, Reticular Formation, Paraventricular nucleus, DM Thalamus

Front 51

What effects Amygdala efferents have on the body?

Back 51

1. Pain suppression
2. Tachycardia, increased blood pressure, respiration
3. Increased vigilance
4. Releases the stress hormone, Corticotrophin-releasing hormone (CRF)
5. Emotion and Fear

Front 52

What is the function of the Amygdala on the PAG?

Back 52

Pain Suppression

Front 53

What is the effect of the Amygdala on the Autonomic Centers of hypothalamus and brainstem?

Back 53

Tachycardia
Increased Blood Pressure
Increased Respiration

Front 54

What is the effect of the Amygdala on the Reticular Formation?

Back 54

Increased vigilance
Startle Reflex

Front 55

What is the effect of the Amygdala on the Paraventricular nucleus of the Hypothalamus?

Back 55

Releases the stress hormone, corticotropin-releasing factor (CRF)

Front 56

What is the effect of the Amygdala on the DM Nucelus of the Thalamus?

Back 56

Emotion and Fear Responses

Front 57

Lesions to the Amygdala produce what syndrome?

Back 57

Kluver-Bucy Syndrome

Characterized by: Tameness, hyperoral, hypersexual, psychic blindness

Front 58

What are the frou characteristics of Kluver-Bucy syndrome?

Back 58

Characterized by:
Tameness,
hyperoral,
hypersexual,
psychic blindness

Front 59

Humans with bilateral lesions of the Amygdala have what syndrome?

Back 59

Urbach-Wiethe syndrome
-may exhibit no fear
- have great difficulty reading the emotions of others
(Think of that eye test in class)

Front 60

The substantia innominata is a major component of what structure?

Back 60

Basal Forebrain

Front 61

The loss of neurons of the NUCLEUS BASALIS of MEYNERT found in the Substantia Innominata are associated with what disease?

Back 61

Alzheimer's