04 The Menstrual Cycle and the Brain

Question 1

phases of the menstrual cycle

Answer 1

• follicular phase
• ovulation
• luteal phase
• bleeding

Question 2

follicular phase

Answer 2

• Multiple follicles in both ovaries
• One follicle becomes dominant follicle
• Dominant follicle produces estrogen
• Estrogen peaks before ovulation

Question 3

Ovulation

Answer 3

• divides follicular and luteal phase
• around day 14
• dominant follicle releases an egg

Question 4

luteal phase

Answer 4

• dominant follicle turns into corpus luteum
• corpus luteum produces progesterone and estrogen
• prepares body for pregnancy

Question 5

Bleeding

Answer 5

• fall in progesterone triggers shedding of the endometrial lining -> period
• premenstrual symptoms due to hormonal changes

Question 6

sex hormones in menstrual cycle

Answer 6

• FSH (Follicle Stimulating Hormone): generally low, decreases after bleeding, peaks shortly before ovulation (as LH), then decreases until 1 week before bleeding, then increase
• E2 (estrogen/estradiol): increases in follicular phase and peaks before ovulation (earlier than FSH and LH), then drop until shortly after ovulation, increase during first half, decrease during second half of luteal phase
• LH (luteinizing hormone): drastically increasing before ovulation, then slowly decreasing and remaining more or less constant
• PG (Progesterone): lowest in follicular phase, rising and peaking in luteal phase, then quick decrease again (triggers period)

Question 7

Estrogen

Answer 7

• produced in ovaries
• men have estrogen too
• main functions: regulates menstrual cycle, indirectly triggers ovulation, development of secondary sex characteristics (e.g. breasts)

Question 8

Progesterone

Answer 8

• produced in ovaries
• men have progesterone too
• main functions: regulates menstrual cycly, prepares body for pregnancy, helps triggering lactation

Question 9

Brain control of menstrual cycle

Answer 9

• Hypothalamus and pituitary gland are command center of endocrine system
• form hypothalamic pituitary ovarian (HPO) axis
• regulates menstrual cycle by secretion of hormones
• dysfunction of HPO-axis as a cause of infertility

Question 10

Emotion

Answer 10

• neurocognitive and somatic components
• dimensions: arousal (quantitative) and valence (qualitative)
• ANS pushes organism towards state of max engagement (“fight-or-flight”, sympathetic) or recreation (parasympathetic)

Question 11

Amygdala and emotions

Answer 11

• 3 main areas: medial (olfaction), basolateral (cortical input), central (hypothalamic output)
• projections to hypothalamus are paramount in linking cortical cognitive states (fear, surprise) to according somatic reactions
• perception of physical state projects back and is integrated into interpretation

Question 12

basal ganglia and emotions

Answer 12

• (esp. dopamine) code for reward intensity in light of reward expectancy and can thereby support feedback-guided learning
• drugs of abuse overwhelm reward system with neurotransmitters and make it less sensitive to naturally occuring rewards

Question 13

direct effects of steroid hormones on mood - problems

Answer 13

complicated to study because steroid hormones interact with each other and with other neurotransmitters

Question 14

estrogen and mood

Answer 14

• positive effect on mood
• peaks in late follicular phase

Question 15

progesterone and mood

Answer 15

• negative effect on mood (e.g. irritability, depression)
• peaks in mid-luteal phase
• high density in brain regions involved in emotions (e.g. amygdala)
• paradoxical effects: anxiolytic and anxiogenic

Question 16

menstrual cycle phases and emotion recognition

Answer 16

• follicular phase: accuracy increases (esp. for sad faces)
• luteal phase: accuracy decreases, but sad and angry faces elicit faster responses and are experienced subjectively as more intense
• sex differences in reaction time are greates in mid-luteal phase, but women are somewhat better at early automatic visual processing than men in general

Question 17

Emotional Memory and Menstruation

Answer 17

• involves the Hypothalamus-Pituitary-Adrenal-Axis (HPA)
• Luteal phase : increased memory & recall correlated positively with progesterone levels, increased spontaneous intrusive memories of traumatic incident (especially if it occurred in the luteal phase as well), increased cortisol reactivity
• but estrogen levels also high in luteal phase, difficult to disentangle effects
• both interact with serotonin as well

Question 18

Menstrual cycle and Emotion: Neuroimaging results

Answer 18

in luteal phase compared to early follicular phase:
- increased amygdala reactivity
- increased anterior cingulate cortex reactivity to neg. emotional stimuli
- increased hippocampus reactivity during affective processing (in late-follicular and mid-luteal phase)
- decreased middle & superior frontal gyri activity in affective processing

Question 19

premenstrual dysphoric disorder - incidence and DSM-5 symptoms, time course

Answer 19

• 2-5% of women in childbearing age, subthreshold 18% of women
• psychological: anxiety, depression, emotional lability
• vegetative: appetite, sleep changes
• physical: acne, breast pain, cramps, headaches
• onset in late luteal phase, remission within 1-2 days after menstruation onset

Question 20

premenstrual dysphoric disorder - findings

Answer 20

• symptom on- and offset closely related to progesterone levels
• lower threshold for amygdala activity in reaction to progesterone
• symptoms possibly triggered by progesterone withdrawal or estrogen?
• impaired emotion recognition and negative bias (not only in luteal phase according to some studies)

Question 21

Estrogen and progesterone receptors

Answer 21

• located in multiple organs/locations, including CNS
• known locations of membrane-associated receptors in the brain: Hippocampus, PFC, nucleus accumbens (Estrogen only)

Question 22

Function of Hippocampus

Answer 22

• paramount importance for declarative (semantic, episodic) memory and spatial orientation
• PET and fMRI activity in learning
• large hippocampi in London cab drivers
• specific activity of hippocampal neurons in declarative memory and orientation tasks (“place cells”)
• hippocampal dysfunction: primarily anterograde amnesia (no new memory formation after damage)

Question 23

Menstrual cycle and hippocampus

Answer 23

• increased gray matter volume in late follicular phase vs. early
• decreased gray matter volume in mid luteal phase vs. late follicular phase
• no differences in memory task across phases
• correlation between hormonal levels and hippocampal gray matter volume present
• estrogen -> higher gray matter volume and progesterone -> lower GM volume, gray matter volume positively correlated with working memory