physiological basis of behavior Flashcards
endogenous clock hypothesis
internal timing mechanism
- not affected by surrounding envt
- built-in schedule that times animals’ behavior
environmental stimulus hypothesis
feedback from surrounding envt changes animal’s priority for certain behavioural patterns overtime
in an environmentally sustained temperature and 24h light cycle, crickets’ clock seems to delay the start of calling by ____ each day. This is the ____ effect. This means that crickets have an internal clock of ____ hours.
When put back into regular light, the calling will soon resume at _____ in a few days, about __ hours before dark.
1-2h; lag; 25-26
dusk; 2
what is free running cycle?
cycle of activity that is not matched to envt cues
when do crickets call via the free running cycle? in an environmentally sustained envt or in the wild?
**free running cycle - cycle of activity that is not matched to envt cues
environmentally sustained envt
true or false. hormones does not play a role in circadian rhythms.
false. hormones can play an activational role in circadian rhythms
sand crickets have polyphenism in circadian rhythm. what are they?
- long-winged, flies during night, and right before that, exhibits JH in late afternoon
- short-winged - flightless, forage on ground during day
what is the difference in effects of ability of circadian rhythm between severing cricket’s eye from optic lobe and optic lobe from brain?
eye from optic lobe - cricket enters free runnning cycle, cannot entrain
optic lobe from brain - circadian rhythm breaks down completely
the timed pacemaker is aka what and resides in the cricket’s where?
master clock
optic lobe
what is the pathway for circadian rhythm?
envt cues –> sensory receptors –> pacemaker (master clock) –> behaviours (observed rhythms)
circadian rhythms are controlled by __________ in ___________ of mammals
SCN (superchiasmatic nucleus); hypothalamus
mutations of which 2 genes affect circadian rhythms?
tau and per
in mice, ___ gene mutation shorten the wildtype 24h circadian rhythm to:
1) heterozygous mutants have _____ h cycle
2) homozygous mutants have ___ h cycle
tau
22
20
does mutation in per gene affects mice or fruit flies’ circadian rhythms?
fruit flies
what animal in the sldies dont have circadian rhythms? how is their activity like then?
naked mole rats (heterocephalus glaber)
irregularly timed, short periods of activity among long periods of rest
does per gene varies between castes in bees?
yes.
those inside the hive and dont usually go outside (queen, nurses) have lower per gene expression compared to those actively outside (foragers) which have more due to their need for active circadian rhythms.
circadian is for every day. what about every year?
circannual
what creature has very strong circannual rhythm?
squirrels
banner tailed kangaroo rats changes their nightly foraging patterns based on which 2 factors?
lunar cycle; predation threat
peak photosensitivity to lght is hours _____ to ____ after dawn.
16-20
what is reproductive readiness hypothesis
animals maintain reproductive readiness for most of the year so that if they encounter favorable conditions for reproduction they can respond by triggering gonad development
outside of breeding season, seasonal finches have regressed ________ and less ____ hormone.
gonads; luteinising (LH)
in non-seasonal finches, males have intermediate testis and LH during the year and females have small ovarian follicles but stable levels of LH. both males and females LH levels were higher than seasonal finches’. what does this mean?
non-seasonal finches are more ready for reproduction compared to seasonal finches, supporting the reproductive readiness hypothesis.
what is the main hormone activating infanticide behavior?
progesterone
female mice that have had past experience with subordinate male mice do/do not have preference for mates. those that have past experience with dominant males have/do not have preference for the same.
do not have
have
progesterone levels in mice decreases/increases from inexperienced male to mated without pups to father?
decreases
what is the main sensation that cause female mice to prefer dominant mice if they have past experience with dominant ones before?
smell
pheromones and odors of dominant males
which stage of the mouse has highest level of testosterone? which has the lowest?
mated without pups - highest
father - lowest
fruit flies become unreceptive after mating, a change triggered by ____.
sex peptide (SP)
associative vs dissociative reproductive pattern
associative - peak sex hormone levels correlated in time with mating activity
dissociative - peak sex hormone levels not are correlated in time with mating activity
do british red deer and green anoles have associative or dissociative reproductive patterns?
associative
what is the challenge hypothesis?
T promotes aggression when it should be for reproduction, eg. mate guarding, repelling rivals
testosterone is a trade off between reproductive readiness and survival. state 2 costs of testosterone.
- reduces immune function
- in vertebrates, males more likely to be harboring infections of bacteria, viruses and parasites
- chimpanzee males with highter T have greater diversity of worms
- dark-eyed junco males with higher T exhibit less paternal care to their young
which throat color of the common side blotched lizard is less likely to survive the mating season? most likely to survive?
least likely to survive - orange
most likely to survive - yellow
does the red-sided garter snake have associative or dissociative reproductive pattern?
dissociative - T does not affect mating/aggression
mating in red-sided garter snake has a dissociative reproductive pattern which means T does not affect mating/aggression. mating in this case is activated by what?
prolonged period of low temp dormancy, followed by warm temp
how do T levels affect mating in red-sided garter snake in the long term?
castrated males with no T levels cease mating after a few years
in red-sided garter snake, what enzyme is present in high levels in the brain during spring emergence?
in which part of the brain is this enzyme present?
what does it trigger?
aromatase
olfactory
male attraction to female pheromone
_________ are referred to as stress hormones in animals. they play an activating role through the ______.
glucocorticoids (GC)
hypothalamic-pituitary-adrenal axis (HPA)
what is the HPA?
hypothalamic-pituitary-adrenal axis
in hierarchical societies, dominants show ___ GC while those who must continually fight for power and survival show ____ GC.
low; high
social support reduce/increase HPA activity.
reduces
