Lecture 22- Autonomic nervous system IV

Question 1

What are emotions?

Answer 1

• Arnold and Glasson, 1954. An emotion or an affect can be considered as the felt tendency towards an object judged suitable, or away from an object judged unsuitable, reinforced by specific bodily changes.
• Barrett and Campos, 1987. We conceive of emotions as bidirectional processes of establishing, maintaining and/or disrupting significant relationships between an organism and the (external or internal) environment.
• Frijda and Mesquita, 1994. Emotions… are first and foremost, modes of relating to the environment: states of readiness for engaging, or not engaging, in interaction with the environment.

Question 2

What are some examples of emotions?

Answer 2

-these emotions have bodily efefcts via the autonomic nervous system

• Pleasure • Elation • Euphoria • Ecstasy • Sadness • Depression • Fear • Anger • Joy • Love • Disgust

Question 3

What is the Kluver-Bucy syndrome?

Answer 3

• bilateral lesion of the amygdala, they don’t know that they should not approach someone, cannot interpret negative faces etc.
• must be bilateral damage otherwise not like this -don’t have a problem with positive faces
• can understand that someone is being negative if described to them -they don’t look at eyes and mouth as much
• the control put much emphasis at the eyes, the disease one doesn’t
• tracking experiment:
• almost avoid eyes
• via the amigdala get bodily response

Question 4

What are the physiological responses to emotional stimuli?

Answer 4

• Psychological stress – Conditioned or Unconditioned
• Produces altered physiological states,e.g.fear – Feeling, Heart pounding, Increased Respiration, Dry mouth, Tense muscles, Sweaty palms, Pupil dilation

Question 5

What happens in the body due to mental stress? (physiologically)

Answer 5

• blood flow to the mesenteric artery changes due to vasoconstriction in the gut
• more blood to the brain
• mental stress leads to increase in heart rate, pressure, and leg sympathetic activity

Question 6

What happens when you activate the dorsomedial hypothalamus?

Answer 6

• due to mental stress!
• activation of the dorsomedial nucleus of the hypothalamus= removing the inhibitory input activation, arterial oressure goes uo, heart rate goes up, renal activity goes up phrenic nerve (breathing) size doesn’t change, so not deeper but breathing faster!
• if have different input will have different activation in the body

Question 7

How was it proven that this stress response is due to the DMH?

Answer 7

• heart rate, when musciline= super GABA, inhibits the neurons in the region
• what do the neurons doing in response to mental stress= heart rate and blood pressure response is not there if the DMH taken out
• specific to DMH, if take out PVN no change

Question 8

Describe the diagram of what happens in the body due to mental stress?

Answer 8

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Question 9

What is this showing?

Answer 9

-DMH is at the crossroads at the middle of many inputs, so all these regulate its activity

Question 10

What happens when you take the amygdala out of the picture?

Answer 10

• response in stress produces higher blood pressure and heart rate
• canuretic acid= blcoker of Glutamate receptor so that stops the amygdala activation, and then the blood pressure and heart rate go back to normal
• stressor (involving cortex) to a,mygdala to DMH

Question 11

What is the amygdala’s role (in terms of the experiment concerning moving muscles through thinking)?

Answer 11

• the experiment where pralysed person activate autonomic system via thinking of moving muscle= the high command, via the amygdala probably
• peripheral afferent coming back through the spinal cord through spinal loop and send info back to the higher centre, this affects the RVLM (critical for driving the outpt of teh autonomic pathways, involving the medulla)
• also the baroreceptor reflex via NTS to CVLM
• from hypothalamic areas get outputs that lead to patterns of changes
• the lines of communication start within the RVLM, private lines coming to beds, then picked off via the inputs of the hypothalamus, PVN and DMH depending on what is needed
• then cortex and amygdala feeding into the hypothalamus to drive changes as needed

Question 12

What are the learning objective? (I)

Answer 12

• The autonomic nervous system, comprising the sympathetic and parasympathetic (and enteric) divisions regulate the activity of the viscera. They have distinct anatomical and neurochemical characteristics.
• The sympathetic division innervates most of the vasculature to maintain and regulate vascular tone.
• The sympathetic and parasympathetic divisions innervate the heart to provide exquisite control of cardiac function.
• The central neural regulation of sympathetic activity is hierarchically organized.
• At the simplest level spinal reflexes regulate SNA – exercise pressor reflex.

Question 13

What are the learning objective? (II)

Answer 13

• Ongoing sympathetic vasomotor activity requires descending excitatory drive – the major source appears to be the RVLM.
• Medullary reflexes enable regulation of cardiovascular function in response to behavioural alterations – e.g. the baroreceptor reflex. Within the medulla circuitry enables reciprocal modulation of sympathetic and parasympathetic activity in the baroreceptor reflex.
• Two groups of RVLM neurons with different neurochemical signatures exist and are involved in different functions.
• RVLM neurons appear to show a viscero‐topic organization enabling independent activation of sympathetic activity to different tissues and vascular beds.

Question 14

What are the learning objective? (III)

Answer 14

• Higher level regulation of sympathetic activity by the hypothalamus enables different patterns to be produced according to need.
• Emotional stimuli induce alterations in sympathetic activity.
• Fear induces a characteristic pattern of autonomic changes that seems to be orchestrated by the dorsal‐medial hypothalamus.
• Whilst not fully elucidated, inputs to the dorsal‐medial hypothalamus from the amygdala are important for producing the autonomic response to fear.