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Behavioral Neuroendocrinology > final exam new material > Flashcards

final exam new material Flashcards

1
Q

what is a stressor

A

stimuli/circumstance that triggers a stress response

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2
Q

what is a stress response

A

physiological/psychological response to stress

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3
Q

what is stress

A

situation in which there is both a stressor and a stress response

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4
Q

what are the two main physiological stress response systems

A

sympathetic nervous system
hypothalamic pituitary-adrenal axis

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5
Q

who is the historical proponent of the SNS

A

walter cannon

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6
Q

who is the historical proponent of the HPA axis

A

hans selye

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7
Q

what is the function of the SNS

A

supports fight or flight response

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8
Q

what is the function of the HPA axis

A

general adaptation syndrome

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9
Q

what is the effector hormone of the SNS

A

adrenaline (epi and NE)

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10
Q

what is the effector hormone of the HPA axis

A

cortisol

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11
Q

what is the speed of onset and duration of action of the SNS

A

rapid
short lasting

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12
Q

what is the speed of onset and duration of action of the HPA axis

A

slow
long lasting

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13
Q

the speed of onset and duration of hormone effects are largely determined by

A

hormone receptor signal transduction mechanisms

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14
Q

what is the purpose of the emotional aspect of stress

A

motivates coping behavior to avoid and/or escape the stressor

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15
Q

why is the general stress response not stressor specific

A

because it is adaptive for dealing with a wide range of physical stressors

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16
Q

why are psychological stressors as effective as physical stressors at triggering a stress response

A

because psychological stressors are potentially cues associated with impending physical stress

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17
Q

what does psychological stress serve as a warning sign of

A

motivate coping behavior to avoid the physical stressor
prepare the body to combat/avoid a physical stressor

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18
Q

what are the three main conditions that are effective psychological stressors

A

lack of controllability
lack of predictability of stressor onset/offset
social relationships

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19
Q

what is the psychological stress “detector” or stress “generator”

A

the brain

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20
Q

what is the greatest ill effect of stress on our health

A

not efficiently turning off a stress response after it has been triggered

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21
Q

what is the ANS

A

autonomic nervous system
motor neural system that innervates periphery organs and is not under voluntary control

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22
Q

what are the two branches of the ANS

A

SNS- fight or flight
PSNS- return to calm state

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23
Q

where does the synapse between the preganglionic and postganglionic neurons take place

A

in ganglia

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24
Q

what is a ganglia

A

large cluster of neuronal synapses

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25
Q

where are the sympathetic chain ganglia located

A

close to the spinal cord

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26
Q

where are the cell bodies of the SNS preganglionic neurons located

A

thoracic and lumbar portion of the spinal cord

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27
Q

are the axons of SNS preganglionic neurons short or long

A

short

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28
Q

where are the axon terminals of SNS preganglionic neurons located

A

sympathetic chain ganglia

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29
Q

where are the cell bodies of the SNS postganglionic neurons located

A

sympathetic chain ganglia

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30
Q

are the axons of SNS postganglionic neurons short or long

A

long

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31
Q

where are the axon terminals of SNS postganglionic neurons located

A

target organs

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32
Q

where are the cell bodies of PSNS preganglionic neurons located

A

brain stem and sacral portion of spinal cord

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33
Q

what kind of sensory info does the vagus nerve send to the brain

A

visceral sensory info

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34
Q

what are the two main types of cholinergic receptors

A

nicotinic
muscarinic

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35
Q

are the axons of PSNS preganglionic neurons short or long

A

long

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36
Q

where is the axon terminal of a PSNS preganglionic neuron located

A

ganglion close to target organ

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37
Q

where is the cell body of a PSNS postganglionic neuron located

A

near target organ

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38
Q

is the PSNS postganglionic axon short or long

A

short

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39
Q

where is the location of the axon terminal in a PSNS postganglionic neuron

A

target organs

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40
Q

what NT is released from the SNS preganglionic neuron

A

ACh

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41
Q

what NT is released from the SNS postganglionic neuron

A

NE

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42
Q

what NT is released from the PSNS preganglionic neuron

A

ACh

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43
Q

what NT is released from the PSNS postganglionic neuron

A

ACh

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44
Q

what is the target receptor type of the SNS preganglionic neuron

A

nicotinic cholinergic receptor

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45
Q

what is the target receptor type of the SNS postganglionic neuron

A

adrenergic receptors
(alpha 1, alpha 2, beta 1, beta 2, beta 3)

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46
Q

what is the target receptor type of the PSNS preganglionic neuron

A

nicotinic cholinergic receptor

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47
Q

what is the target receptor type of the PSNS postganglionic neuron

A

muscarinic cholinergic receptor

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48
Q

where does the specificity in the response occur

A

at the receptor on the target organ

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49
Q

what is one target organ that provides the same response in both the SNS and PSNS

A

salivary (both secrete saliva)

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50
Q

what is found in the plant called belladonna

A

atropine

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51
Q

what role does PSNS activation play in male orgasm

A

erection

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52
Q

what role does SNS activation play in male orgasm

A

ejeculation

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53
Q

what kind of sexual dysfunction can stress lead to

A

too much SNS activation can inhibit erection or lead to premature ejaculation

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54
Q

what is the hormonal (endocrine structure) component of the SNS

A

adrenal medulla

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55
Q

where is the adrenal gland located

A

on top of the kidney

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56
Q

what neuron directly innervated the adrenal medulla

A

SNS preganglionic neuron

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57
Q

what kind of endocrine cells contain epi and NE

A

chromaffin cells

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58
Q

is epi and NE located in the adrenal medulla or adrenal cortex

A

adrenal medulla

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59
Q

is more epi or NE produced and released

A

3-10 times more epi

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60
Q

what controls the secretion of epi and NE

A

SNS preganglionic neurons

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61
Q

what kind of NT is epi/NE

A

monoamine

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62
Q

are monoamines stored in vesicles

A

yes

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63
Q

where are the cell bodies of the SNS neurons that innervate the adrenal medulla located

A

thoracic spinal cord

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64
Q

what kind of receptors are on the surface of chromaffin cells

A

nicotinic cholinergic receptors

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65
Q

is there a RH controlling epi/NE secretion

A

no
it is not an effector hormone of a third order neuroendocrine arrangement

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66
Q

how do epi and NE have different effects in the body

A

they interact with different combinations of adrenergic receptor subtypes

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67
Q

what receptors does NE bind to

A

alpha 1
alpha 2
beta 1

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68
Q

what receptors does epi bind to

A

alpha 1
alpha 2
beta 1
beta 2
beta 3

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69
Q

what kind of receptors are found more in the heart

A

beta 1

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70
Q

what kind of receptors are found more in the lung

A

beta 2

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71
Q

what is primatene mist

A

an effective bronchodilator (active ingredient is epi) but has a side effect of increased heart rate

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72
Q

what is the james lange theory of emotion

A

we “feel” stressed because of the physiological changes in our body

our physiological response to stress can increase our emotional stress response

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73
Q

do epi and NE cross the BBB

A

no because they are monoamines and therefore are not lipid soluble and can be in vesicles

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74
Q

what does the bottom up component of psychological stress refer to

A

we can suppress emotional stress response by suppressing the SNS response

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75
Q

what is one pharmacological way that we can suppress emotional stress response by suppressing the SNS response

A

beta adrenergic receptor blockers that will inhibit many of the actions of epi and NE on target organs

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76
Q

what is one behavioral way that we can suppress emotional stress response by suppressing the SNS response

A

relaxation techniques: designed to suppress SNS and PSNS activity

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77
Q

what is an example of a glucocorticoid

A

cortisol

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78
Q

what is the molecular structure of cortisol

A

steroid hormone
(lipid soluble, crosses BBB, no vesicles)

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79
Q

what neuroendocrine circuit is cortisol the effector hormone of

A

hypothalamic pituitary adrenal axis

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80
Q

who was kurt vonnegut

A

an author

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81
Q

what was hans selyes most famous discovery

A

HPA axis
general adaptation syndrome

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82
Q

what is the general adaptation syndrome triad of chronic stress effects

A
  1. adrenal hypertrophy
  2. involution (shrinkage) of the thymus gland
  3. ulcers
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83
Q

how does chronic stress cause adrenal hypertrophy

A

chronic activation of the HPA axis causes increased CRH > increased ACTH
ACTH is a trophic factor for the adrenal cortex so the adrenal cortex will increase in size

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84
Q

where do CRH neurons receive input from

A

the BNST, other hypothalamic subnuclei and some brainstem nuclei
do not receive direct sensory and cortical input

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85
Q

do CRH neurons receive information in order to determine if an event is “stressful” or not

A

no

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86
Q

what happens in the thymus gland

A

T lymphocytes mature

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87
Q

what are T lymphocytes involved in

A

specific immunity

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88
Q

why does cortisol cause the thymus to shrink

A

cortisol can kill T cells

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89
Q

what can T cells in the body discriminate against

A

infected cells and healthy cells

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90
Q

what kind of T cells does cortisol kill

A

the autoreactive (bad) T cells but too much cortisol can cause the good T cells to get killed off as well

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91
Q

how does chronic stress cause ulcers

A

we dont know
could be more of an effect of adrenaline than cortisol

92
Q

what is helicobacter pylori

A

the bacterium responsible for causing ulcers

93
Q

does chronic stress cause ulcers

A

not directly
stress can cause microbiome changes that can contribute to more helicobacter pylori but ulcers are not directly modulated by stress

94
Q

what are the targets for glucocorticoids

A

any cell that expresses a glucocorticoid receptor (most cells in the body)

95
Q

where in the body does not have receptors for glucocorticoids

A

suprachiasmatic nucleus (circadian rhythms)

96
Q

what are the two subtypes of receptors for cortisol

A

mineralocorticoid receptor
glucocorticoid receptor

97
Q

what is the difference between the two subtypes of cortisol receptors

A

MR: high affinity for cortisol; more sensitive to changes in cortisol
GR: lower affinity for cortisol

98
Q

is cortisol a glucocorticoid

A

yes

99
Q

what is the difference in distribution between MR and GR

A

GR is widely distributed throughout the body
MR has restricted distribution and is high in the hippocampus and the kidney

100
Q

what does survival of granule neurons in the hippocampus (memory) require

A

daily cortisol activation of MR

101
Q

what do MRs in the kidney primarily respond to

A

aldosterone

102
Q

what does aldosterone regulate

A

sodium retention

103
Q

what are some pharmacological uses of glucocorticoids

A

based on the immunosuppressive and anti-inflammatory effects

104
Q

what is dexamethasone

A

potent glucocorticoid receptor agonist
(used in covid treatment)

105
Q

what is cushings syndrome

A

excessive chronic glucocorticoid levels that is sometimes the result of an adrenal or pituitary tumor

106
Q

can glucocorticoid levels be measured in the blood and saliva

A

yes

107
Q

because cortisol is a steroid, a saliva sample will contain what

A

the CBG unbound “free” levels of cortisol

108
Q

what are two factors that regulate HPA axis activity

A

strong circadian rhythm
stress

109
Q

what is the nadir

A

trough (low-point) during behavioral inactive period
humans: night
nocturnal animals: day

110
Q

when is the peak in HPA axis activity

A

right at the time of awakening

111
Q

what are three examples of stressors that can interfere with HPA axis activity

A

physical stressors: hemorrhage, pain, fasting, etc
alcohol: increases cortisol/decreases vasopressin, stimulates HPA axis
cytokines

112
Q

what are cytokines

A

immune system derived hormone that potently activate the HPA axis

113
Q

why should the immune system activate the HPA axis

A

HPA axis may serve as a negative feedback modulator for the immune system (help keep the immune system in check)

114
Q

why is glucocorticoid negative feedback of the HPA axis important

A

too much glucocorticoid exposure produces too many of the pathological consequences of chronic stress

115
Q

how do glucocorticoids provide direct negative feedback on the HPA axis

A

cortisol acts directly on PVN neurons and/or corticotrophs

116
Q

is cortisol a glucocorticoid

A

yes

117
Q

how do glucocorticoids provide indirect negative feedback on the HPA axis

A

cortisol acts on other brain areas that indirectly inhibits PVN neurons

118
Q

what is fast feedback (in relation to glucocorticoids and the HPA axis)

A

glucocorticoids can rapidly attenuate the HPA axis response to stress (mechanism is too rapid to require gene transcription)

119
Q

what is delayed feedback (in relation to glucocorticoids and the HPA axis)

A

kicks in after stress onset (30-60 min) and only partially suppresses subsequent HPA axis activity

120
Q

what is biological psychiatry

A

study of biologic basis of psychiatric disorders to find a physiological biomarker/indicator of psychiatric disorder

121
Q

what is the difference between a trait marker and a state marker

A

trait marker: life-long symptom of someone predisposed to a particular disorder (ex. genes)
state disorder: symptom that is present only during the expression of the disorder (ex. hormones)

122
Q

what are two examples of HPA axis dysregulation in major depression

A
  1. hypercortisolemia: elevated basal cortisol especially through circadian trough
  2. impaired DST result
123
Q

what is DST

A

dexamethasone test
- a potent synthetic glucocorticoid receptor agonist

124
Q

what is the procedure for the dexamethasone supression test

A

at bedtime, subject takes 1mg DST tablet
following morning and afternoon, blood samples are obtained and cortisol levels are measured

125
Q

what is the normal response to a DST

A

suppressed basal cortisol levels because of increased negative feedback

126
Q

what is a possible implication of an abnormal DST response in depressed individuals

A

these individuals may have impaired glucocorticoid negative feedback function

127
Q

what are two other disorders that are found to be associated with hypocortisolemia

A

PTSD
chronic fatigue syndrome

128
Q

what is the relationship between depression and stress

A

stress may exacerbate and/or trigger depressive episodes but does not CAUSE depression

129
Q

what is the period

A

time duration to complete one cycle

130
Q

what is the peak/zenith

A

maximum; value of high point

131
Q

what is the trough/nadir

A

minimum; value of low point

132
Q

what is the amplitude

A

absolute value of the difference between peak or nadir and the mid-point

133
Q

what is the frequency

A

number of cycles per given amount of time (inverse of period) (ex. 1 cycle per day)

134
Q

what is the mesor

A

average value (midpoint of the waves)

135
Q

what is the phase

A

synchronization of 1 cycle with another cycle or some other temporal event

136
Q

how many degrees is 1 cycle

A

360 degrees

137
Q

what is it called when 2 cycles are 180 degrees out of phase with each other

A

antiphasic

138
Q

what is circadian

A

around the day
24 hr period

139
Q

what is the difference between diurnal, nocturnal, and crepuscular

A

diurnal: active during the day
nocturnal: active during the night
crepuscular: active at dawn and dusk

140
Q

what is circalunar

A

approx 28 day cycle
(menstrual cycle)

141
Q

what is circatidal

A

approx 12 hr cycle - tides
(fiddler crab activity)

142
Q

what is circannual

A

approx 1 yr cycle
(breeding, hibernation, body weight, fur growth, migration)

143
Q

what is the difference between ultradian and infradian

A

ultradian: period less than 24 hrs
infradian: period greater than 24 hrs

144
Q

what does “zeitgeber” mean

A

“time giver”

145
Q

what is chronobiology

A

study of the timing of biological rhythms

146
Q

in hamsters, if the time of lights off is shifted to three hrs later, will the hamster shift their wheel running time to 3 hrs later

A

yes

147
Q

if a hamster is kept in constant darkness, what will happen to its running patterns

A

they will keep a regular running schedule indefinitely

148
Q

what kind of rhythm do hamsters running on wheels have

A

endogenous circadian activity rhythm
(doesn’t need environmental cue to maintain rhythm but can be entrained by the light/dark pattern)

149
Q

what does entrainment of biological rhythms mean

A

environmental periodic cue that synchronized endogenous rhythm

150
Q

what is a free running biological rhythm

A

expression of an endogenous rhythm in the absence of entraining cues

151
Q

why is the definition of stress circular

A

we only know what the stress response is by observing the response to stressors and we only know what a stressor is by observing a stress response

152
Q

do stressors have a physical dimension of “stressfulness”

A

no

153
Q

what is a possible reason for the fact that some people are morning people and some are not

A

implies that some people may have an endogenous period greater than 24hrs

154
Q

what is the relationship between winter and seasonal affective disorder

A

in the winter the lack of morning light may lead to free running rhythms and desynchronization of rhythms that will contribute to SAD

155
Q

what part of endogenous rhythms shows inheritance patterns

A

the period of the endogenous rhythms

156
Q

what are the six biological clock characteristics

A

inheritance
temperature independence
resistance to chemical intervention
limits of entrainment
independence of behavioral feedback
ubiquity of clocks

157
Q

what are the five mammalian clock genes

A

[+] clock
[+] bmall
[-] per1, per2, per3
[-] cry1, cry2, cry3
casein kinase 1e

158
Q

what clock genes are on the positive arm

A

clock
bmall

159
Q

what clock genes are on the negative arm

A

period (per)
cryptochrome (cry)

160
Q

what is FASPS

A

familial advanced sleep-phase syndrome

161
Q

is the endogenous rhythm resistant to temperature fluctuations

A

yes

162
Q

what drugs can lengthen the endogenous circadian period

A

lithium
alcohol

163
Q

how much can a phase shift in one day

A

approx 1 hr per day

164
Q

what is the maximum length the human endogenous clock can be lengthened or shortened (period)

A

2-3 hours

165
Q

is the endogenous biological rhythm dependent on behavior

A

no, endogenous rhythm will continue regardless of behavior

166
Q

what organisms have endogenous clocks

A

all organisms including single celled

167
Q

what brain region is responsible for the endogenous clock

A

suprachiasmatic nucleus of the hypothalamus (SCN)

168
Q

where is the SCN located

A

just above the optic chiasm

169
Q

what happens when the SCN is lesioned

A

expression of endogenous biological rhythms is abolished

170
Q

what input do SCN afferents receive

A

direct input from retina

171
Q

what kind of activity do SCN neurons in a culture dish show

A

rhythmic activity pattern with a period very close to 24 hours

172
Q

what happens when SCN cells are transplanted from a fetal donor hamster to a brain of a hamster whose SCN has been lesioned

A

transplant restores biological rhythm

173
Q

when the rhythm of the lesioned hamster was restored, was the period the same as the donor cells or the pre-lesioned host

A

period was the same as the donor cells

174
Q

T or F: the SCN functions as a light entertainable master pacemaker for the body

A

true

175
Q

how does the SCN talk to the rest of the body

A

cortisol
melatonin

176
Q

when are cortisol levels high in humans and what does cortisol signal

A

levels are high in the morning and it is the wake up signal in all mammals

177
Q

when are melatonin levels high in humans and what does melatonin signal

A

levels are high at night (even in nocturnal animals) and it is the sleep signal in humans

178
Q

where is melatonin produced

A

pineal gland

179
Q

where is the pineal gland located

A

attached to dorsal surface of brainstem right above the superior colliculus

180
Q

what is the chemical structure of melatonin

A

related to serotonin (monoamine) but is lipid soluble

181
Q

what are the targets of melatonin

A

high density of MT1 and MT2 receptors in the hypothalamus

182
Q

how does melatonin secretion change over the lifetime

A

highest during childhood
declines around puberty
low in old age

183
Q

what kind of neurons innervate the pineal gland

A

special postganglionic neurons of the SNS

184
Q

SNS postganglionic neurons that innervate the pineal gland stimulate the production and release of melatonin by stimulating what receptors

A

adrenergic receptors in the pineal gland

185
Q

what stimulates serotonin conversion to melatonin in pineal cells

A

norepinephrine

186
Q

how much light is sufficient to shut down melatonin secretion in hamsters

A

single light pulse (0.1 lux)

187
Q

how much light is thought to turn off human melatonin secretion

A

exposure to bright sunlight (1500 lux)

188
Q

are clock genes only found in the SCN

A

no, whole body

189
Q

what causes retinal ganglion cells to be able to directly sense light

A

protein called melanopsin

190
Q

where do retinal ganglion cells containing melanopsin project to

A

directly to the SCN

191
Q

what kind of light are the intrinsic photosensitive retinal ganglion cells (ipRGCs) most activated by

A

short (blue) wavelength light

192
Q

what causes jet lag

A

consequences of suddenly having endogenous circadian rhythms out of phase with light/dark cycle

193
Q

what does subjective day and night refer to

A

individuals circadian night and day

194
Q

what happens during phase advance

A

subjective night and day begins earlier

195
Q

what happens during phase delay

A

subjective night and day begins later

196
Q

to produce a phase advance when would the individual need light and melatonin exposure

A

light during the second half of their subjective night

melatonin in late afternoon/early evening

197
Q

to produce a phase delay when would the individual need light and melatonin exposure

A

light during first half of subjective night

melatonin in early morning

198
Q

what are physiological changes that occur in hamsters as winter approaches

A

decrease eating
fur thickens
decreased HPG activity
hibernation

199
Q

what are physiological changes that occur in hamsters as spring approaches

A

increased HPG activity
shedding of fur
mating and child rearing

200
Q

what is the zeitgeber for hamsters switching behavior for the seasons

A

environmental cues: temp, humidity, weather patterns, amount of sunlight
photoperiod: daylight length

201
Q

what behavior is seen when hamsters are maintained on a long day photoperiod

A

hamsters behave as if its summer indefinitely

202
Q

what behavior is seen when hamsters are maintained on a short day photoperiod

A

hamsters behave as if its winter but after 20-30 weeks, summer behavior and physiology spontaneously emerges

203
Q

what is the refractory to short-day photoperiod

A

after 20-30 weeks of short-day photoperiod, hamsters no longer respond to short-day photoperiod

204
Q

is the refractory period to photoperiods permanent

A

no
if hamsters are exposed to long day photoperiod for approx. 10 weeks they will become sensitive to short day photoperiod

205
Q

what environmental cue does the secretion of melatonin depend on

A

the duration of darkness

206
Q

mammals are exposed to more melatonin each day in what season

A

winter

207
Q

during a long day (summer) photoperiod, what happens if the hamster is treated with a winter-time melatonin secretion pattern

A

hamster goes into winter mode
hamster will become refractory to the additional melatonin treatment after 20-30 weeks

208
Q

hamsters have greater HPG activity in which season

A

in the summer

209
Q

what is the relationship between photoperiod and gonadal steroid negative feedback

A

during the winter, HPG axis exhibits greater negative feedback sensitivity to gonadal steroids

210
Q

what is the relationship between melatonin and gonadal steroid negative feedback

A

melatonin increases negative feedback sensitivity of GnRH neurons to gonadal steroids

211
Q

what are some symptoms of seasonal affective disorder that are atypical for depression

A

hypersomnia
carbohydrate cravings
excessive weight gain

212
Q

when during the day will bright light most benefit those with SAD

A

in the morning

213
Q

what is the implication of bright light helping with SAD more in the morning

A

benefit is not just a general effect of bright light but depends on bright light adjusting (advancing) the circadian phase

214
Q

what is the circumstantial evidence for the role of gonadal steroids to modulate mood in women

A

women note changes in mood:
around time of menstruation
shortly after child birth
around the period of menopause
starting/ending oral contraceptive use

215
Q

when does premenstrual dysphoric disorder occur during menstrual cycle

A

symptoms occur during last week of luteal phase and remitted within a few days after onset of the follicular phase

216
Q

is PMS a result of changing activational effects of hormones

A

there are no clear differences in progesterone and estrogen profiles of women with PMDD vs women without PMDD

217
Q

where is there a high concentration of estrogen receptor alpha

A

ovary, uterus, mammary glands, hypothalamus

218
Q

where is there a high concentration of estrogen receptor beta

A

kidney, bone, heart, cerebral cortex

219
Q

what are three treatments of PMDD

A
  1. block luteal phase with a progesterone antagonist (no benefit)
  2. prevent entire cycle with GnRH agonist (was effective)
  3. progesterone and thyroid hormone treatment (was effective in many cases)
220
Q

how much input do CRH neurons in the PVN of the hypothalamus receive

A

no direct input but get indirect input from other brain structures

221
Q

what in biochemical terms oscillated in order to generate a molecular clock

A

positive arm drives expression of negative arm
negative arm inhibits expression of positive arm

222
Q

how can an SCN be transplanted from one hamster into another

A

SCN cells from fetus are injected into the 3rd ventricle, attach to wall of third ventricle and makes synaptic contact with brain

223
Q

is melatonin a neurohormone

A

no because it is not produced by a neuron

224
Q

what is a neurohormone

A

a hormone produced by a neuron

225
Q

how is melatonin secretion controlled

A

SCN (suprachiasmatic nucleus) projects to the PVN (paraventricular nucleus) which controls the HPA axis ; the PVN projects to the SCG (superior cervical ganglion) and the SCG directly innervates the pineal gland

226
Q

what is the circadian pattern of melatonin secretion in rodents and humans

A

high at night for all mammals
sleep signal in humans but not sleep signal for rodents

227
Q
A

Behavioral Neuroendocrinology (6 decks)

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