8.12. Integration of autonomic responses. Regulation of behavioral mechanisms. Motivation. Emotion.

Question 1

I. Autonomic NS integration
1. Explain The autonomic responses

Answer 1

The autonomic responses of the PARA and SYM nervous systems are closely integrated with both somatomotor and endocrine responses

Question 2

I. Autonomic NS integration
2A. Where are autonomic nuclei located? Where does these autonomic nuclei lead to?

Answer 2

Located in the intermediolateral (IML) region of the spinal cord grey matter OR in brainstem nuclei (brainstem nuclei are only for PARA).
-> These autonomic nuclei lead to the preganglionic neuron axon fibers that normally synapse in a ganglion, then give postsynaptic fibers to a target cell

Question 3

I. Autonomic NS integration
2B. How are autonomic nuclei controlled?

Answer 3

Primarily controlled by the hypothalamus, however, they may also be stimulated by pain receptors, thermoreceptors and visceroreceptors

Question 4

I. Autonomic NS integration
2C. What do autonomic nuclei target?

Answer 4

They target the somatomotor system and endocrine glands and are responsible for some unconscious reflexes

Question 5

I. Autonomic NS integration
2D. What is the role of pain receptors? (autonomic nuclei)

Answer 5

Pain receptors can activate a defensive reflex that includes both SYM response AND skeletal muscle activity

Question 6

II. Cardiovascular reflex
2. What is the role of pressor center?

Answer 6

Pressor center: targets SYM neuron pathways targeting the heart, vessels, adrenal gland

Question 7

II. Cardiovascular reflex
3. What is the role of DEpressor center?

Answer 7

Depressor center: inhibits the pressor center itself, inhibits the synapses between the pressor center and SYM nuclei, and also PARA innervation of the heart

Question 8

III. Pupil reflex
1. Describe pupil reflex

Answer 8

• Basal activity is mostly sympathetic, meaning the pupils are dilated via information from the first 1st thoracic segment
• PARA response comes from light stimulation on the retina, which leads to pupillary constriction

Question 9

III. Pupil reflex
2. Describe regulation of water uptake (hypothalamus?

Answer 9

• Hypothalamus is able to sense the need for water via circumventricular organ connections, where the BBB is incomplete
• These receptors are activated by high osmolarity, ANGII or peripheral receptor activation (low-pressure baroreceptors)
• Hypothalamus reacts by producing ADH as well as stimulating somatomotor activity that drives the animal to seek out water to drink

Question 10

III. Pupil reflex
3. Describe Fight-or-flight reflex (hypothalamus)?

Answer 10

• Hypothalamus induce SYM activation + somatomotor responses and activation of the endocrine system (ACTH/glucocorticoid production)
• What is perceived as dangerous is involved in memory of your experiences, therefore, the hypothalamus works together with the limbic system and amygdala

Question 11

IV. Non-cognitive behavior control
1. Which parts of the brain that are responsible for Non-cognitive behavior control?

Answer 11

• Paleocortex, diencephalon and brainstem are responsible for the non-cognitive behavior and emotion.
• It is a relatively ancient system and consists of hypothalamus, reticular formation, monoaminergic system and the limbic system

Question 12

IV. Non-cognitive behavior control
2. Give some examples of non-cognitive behavior control

Answer 12

Examples of non-cognitive behavior control: include a wide array of mechanisms that are common in animals and/or humans:
- Control of alertness
- Mood
- Hunger, thirst
- Fear, rage, aggression
- Fight or flight
- Sexuality
- Self-defense and altruism
- Migration

Question 13

IV. Non-cognitive behavior control
3A. What is the role of neural centers?

Answer 13

Neural centers: the brain controls these unconscious behaviors through a variety of neural centers and their neurotransmitter

Question 14

IV. Non-cognitive behavior control
3B. What are the 4 important neural centers?

Answer 14

1. Reticular formation
2. Locus ceruleus
3. Substantia nigra
4. Raphe nuclei

Question 15

IV. Non-cognitive behavior control
3C. What is the role of reticular formation?

Answer 15

Reticular formation: acts as filter for the sensory system and modulates sensory pain signals, sometimes to increase/decrease their sensation. It also creates excitatory signals up to the cortex to affect motor action, and inhibitory signals that can induce sleep

Question 16

IV. Non-cognitive behavior control
3D. What is the role of Locus ceruleus?

Answer 16

• It is located in pons and produces NE.
• This center aids in alertness and excitatory control.
• Locus ceruleus is responsible for REM sleep and target of many drugs such as cocaine + amphetamine

Question 17

IV. Non-cognitive behavior control
3E. What is the role of Substantia nigra?

Answer 17

Substantia nigra: located in mesencephalon and produces dopamine. Dopamine can be both inhibitory (D2 – G1) and excitatory (D1 -G2)

Question 18

IV. Non-cognitive behavior control
3F. What is the role of Raphe nuclei?

Answer 18

• Raphe nuclei: located in pons + medulla.
• Nuclei produce serotonin and send efferentations to diencephalon, cortex and spinal cord.
• The nuclei is used to modulate pain sensation and is generally inhibitory

Question 19

V. Limbic system
1. What is another name of lambic system?

Answer 19

paleocortex – ancient part of brain

Question 20

V. Limbic system
2. What are the features of limbic system?

Answer 20

• Responsible for feeling of rage, fear, panic, vigilance, feelings of being lost/lonely,
  sexuality, reward, punishment, regret and care
• It is the emotional brain and consists of many parts that make up a ring structure
  bordering the cortex

Question 21

V. Limbic system
3A. What is the role of hypothalamus in limbic system?

Answer 21

The hypothalamus is involved in the limbic system, as well as the control center of all vegetative functions that accompany affection
- Lateral hypothalamus: increased activity, rage and fighting feelings
- Ventromedial: tranquility, safety
- Anterior: sexuality
- Paraventricular: oxytocin production, erections

Question 22

V. Limbic system - Hypothalamus
3B. What is the role of lateral hypothalamus?

Answer 22

increased activity, rage and fighting feelings

Question 23

V. Limbic system - Hypothalamus
3C. What is the role of Ventromedial hypothalamus?

Answer 23

tranquility, safety

Question 24

V. Limbic system - Hypothalamus
3D. What is the role of Anterior hypothalamus?

Answer 24

sexuality

Question 25

V. Limbic system - Hypothalamus
3D. What is the role of Paraventricular hypothalamus?

Answer 25

oxytocin production, erections

Question 26

V. Limbic system
4. What is the role of Hippocampus, dentate gyrus?

Answer 26

responsible for long-term memory and affections

Question 27

V. Limbic system
5. What is the role of Amygdala?

Answer 27

• Motor control of rage, reward, escape, pleasure + involuntary actions such as licking, chewing, eating etc.
• There is some SYM and PARA reactions including BP, HR, GI-motility, secretion, defecation, pupillary reactions, erection control => basically everything affects everything

Question 28

VI. Limbic circuits
1. How are Limbic circuits activated?

Answer 28

Activated by sensory input or smell (among many things), and this activates the thalamus or amygdala to begin the circuit that transcends to the prefrontal cortex or cingulate gyrus

Question 29

VI. Limbic circuits
2. Describe Papez’ circuit

Answer 29

• Activated from the cingulate gyrus
  -> parahippocampla gyrus
  -> entorhinal cortex
  -> subiculum
  -> fornix
  -> mamillary bodies
  -> thalamus
  -> back to cingulate gyrus
• The output of the limbic circuits includes hormonal release and motor responses, whether they are conscious or unconscious

Question 30

VI. Limbic circuits
3. Make a schematic diagram of Papez’ circuit

Answer 30