(17) Limbic System

Question 1

(Limbic System)

(Historical)

1. Limbic refers to the fact that the cortical structures which compirse the system form a what?
2. these structures are involved in what?
3. these structures along with what were collectively called the limbic system?

Answer 1

1. border around the brainstem
2. emotion
3. components of the hypthalamus, thalamus, and epithalamus

Question 2

(Functions)

1-2. In domestic animals the limbic system is concerned with what two things?

(emotions of importance to survival)

3. escape, defense, and feeding are examples of what?
4. territorial defense, courtship, mating, etc examples of what?

Answer 2

1. emotions of importance to survival
2. processes involved in learning and memory
3. emotions associated with self-preservation
4. emotions associated with species-preservation

Question 3

1-3. What are the three criteria for being included in the limbic system?

Answer 3

1. rich innervation by axons containing indoleamine (i.e. serotonin) and/or catecholamine (i.e. dopamine or epinephrine) NT
2. low threshold for seizure activity
3. direct or indirect connections to the hypothalamus

Question 4

1-7. What are the seven components of the Limbic System?

Answer 4

1. hippocampus
2. cingulate gyrus
3. amygdala
4. septal area
5. portions of the thalamus
6. piriform lobe
7. mamillary bodies of the hypothalamus

Question 5

(Individual Limbic Structures and Possible Functions)

(Part I)

1. Some areas of the brain are neither purely sensory nor purely motor but instead are what?
2. Do the limbic system components represent one of these modulatory systems?
3. but the limbic system components are nevertheless what?
4. Complex behaviors are often directed toward filling a primary need such as what three things?
5. Are different types of emotions and emotional responses withing the limbic realm?

Read the rest of the first paragraph!!!

Answer 5

1. modulatory
2. yes
3. essential components of the neural circuitry underlying complex behaviors
4. hunger, thirst, or sleep
5. yes

Question 6

(Individual Limbic Structures and Possible Functions)

(Part II)

1. In general the neocortex has what kind of effect on emotional behavior?
2. This is illustrated by a type of rage reaction that occurs following the removeal of the cerebral cortex from a cat or a dog?
3. It is characterized by what?
4. Why is it called sham rage rather than genuine rage?

Answer 6

1. dampening effect
2. sham rage
   * 3.* lashing of tail, arching of back, clawing and attempts to bite, autonomic responses
3. anger occurs spontaneously or can be triggered by mild tacticle or non-noxious stimuli

Question 7

(Individual Limbic Structures and Possible Functions)

(Hippocampus)

1. structure?
2. long been thought to be an important cortical region for what? particularly what?
3. Both amnesia patients and animals with hippocampal damage exhibit what behavioral tasks? generally described as what in nature?
4. Does this area of brain have low or high seizure threshold?

Answer 7

1. simple, three layered cortical structure (archicortex)
2. associative learning and memory; particularly memory acquisition or short term memory
3. time-dependent impairments; associative or retinal in nature
4. low

Question 8

(Individual Limbic Structures and Possible Functions)

(Septum)

1-4. a small but conspicuous cortical area that is involved in a variety of physiological and behavioral processes inculding what four things?

5. stimulation induces what type of behavior and can suppress what responses?
6. Lesions result in what? can trigger what?

Answer 8

1. emotions
2. relief of fear
3. docile behavior and stress
4. autonomic regulation (water/food intake, hibernation, etc)
5. induce docile behavior and suppress many autonomic responses
6. rage and aggressive behavior; many autonomic responses

Question 9

(Individual Limbic Structures and Possible Functions)

(Amygdala)

1. a highly differentiated region near what pole of the mammalian cerebral hemisphere?
2. It is a basal nucleus that is implicated in what functions?
3. include what?
4. Many amygdala effects appear same or opposite to those of the septum?
5. lesions result in what? stimulation produces what?

Answer 9

1. temporal pole
2. a bewildering variety of behavioral and regulatory functions
3. emotion, memory, social behaviors like reproduction, fear and agression, and modulation of the autonomic and neuroendocrine systems
4. opposite
5. docile behavior; rage and aggressive behavior

Question 10

(Individual Limbic Structures and Possible Functions)

(Hypothalamus)

1. the functions of this have been noted previously
2. Because of its interconnections with other limbic structures - stimulation of the hypothalamus produces what?
3. stimulation reveals what sites as well as sites that produce what kinds of behavior?
4. pigs exposed to acute immobilzation stress show dramiatic increase in what in the hypothalamus?

Answer 10

1. -
2. many of the behaviors seen with stimulation of other limbic sites
3. stimulation reveals rage and aggression sites as well as sites that produce cowering or docile behavior
4. noradrenaline and adrenaline

Question 11

(Individual Limbic Structures and Possible Functions)

(Thalamus)

1. links the what to the what?
2. provides a means by which sensory information can do what>?

Answer 11

1. limbic system to the neocortex
2. gain access to the limbic system

Question 12

(key concept)

1. each of the above limbic structures has been assigned certain functions, however it is important to appreciate what?

Answer 12

1. that these strucutres work together to ultimately give rise to behavior that the animal exhibits

Question 13

Clinical Signs Associated with Damage to Limbic Strucutres

10 of them

DIP SID LSD F

Answer 13

1. dullness
2. irrability or aggressiveness
3. propulsive pacing or circling
4. sleepiness
5. inability to learn
6. destructive behavior
7. lethargy
8. stupor or semicoma
9. dementia
10. failure to recognize owners or familiar environment