Physiological Basis of Behavior Flashcards
(24 cards)
what is the environmental stimuli hypothesis for daily rhythm?
animals rely on feedback information from the environment
what is the endogenous clock hypothesis for daily rhythm?
endogenous (internal: within the brain) timing mechanism that directs behavior
free running cycle
the circadian rhythm the body follows when external factors are absent
retina
detect visuals
what happens when the connection of retina and optic lobes are cut?
very similar to the crickets in 24hrs daylight, free running cycle
what happens when the connection of optic lobes and rest of the brain is cut?
still calls but no circadian rhythm
when connection of optic loves and the rest of the brain is cut, crickets have no circadian rhythm. what does this mean?
internal clock is likely located in the optic lobe (pacemaker)
hypothalamus
regulate behavior including circadian rhythm
what is the brain region that regulates the internal clock?
suprachiasmatic nucleus - SCN
what happens when there lesions on SCN of adult hamster?
eliminate circadian rhythm, disorganized activity
what would be a control for brain lesions?
researchers should perform surgeries on all the objects but some with lesion and some without
eclosion assay
when insects come out of an egg
do Drosphila hatch at specific times and why?
since they have a short lifespan, they hatch at a specific time to prevent wasting time at a less beneficial time
EMS mutagenesis
EMS causes random mutation and hope to mutate the gene of interest (circadian rhythm)
where is the per protein?
photoreceptors in the eyes and some cells in the optic lobes
what gene is for the internal clock?
peroid gene
how does per gene function?
per gene expressed -> transcribed -> cytoplasm -> translated -> bind to TIM -> nucleus -> regulate + inhibit period gene -> no per gene present -> cycle repeats
what happens to the protein that are no longer produced?
they are degraded
how does male stonechats regulate reproduction cycle?
their testis shrink during non-mating seasons
long photoperiods
stimulate reproductive development in captive non-breeding birds
what happens to the gonadal response when stonechats wear black contact lenses?
do not block gonadal response to long photoperiods
what happens to the gonadal response when injecting black ink under the scalp?
blockage in gonadal response to long photoperiods
what does the results show when stonechats wear black contacts and inject black ink under the scalp?
light is important but not acting on the eyes, but the reproductive development is directly affecting by the brain
GnRH (gonadotrophin hormone relasing hormone)
release sex hormones
