lecture 4 - hormones and neurobiology Flashcards
(41 cards)
when do proximate factors operate
within an animal lifetime
what type of questions are proximate factors
how
what do proximate factors relate to
causation and development
what do ultimate factors relate to
function and evolution
what type of questions are ultimate factors
why question
how do ultimate and proximate perspectives relate
knowing information about one another can help us design our questions about the other
they can provide focus on where to approach the opposite type of analysis
how can proximate analysis help understand natural selection
helps us understand the raw material that natural selection may operate on in the future
what does proximate analysis shed light on
neurobiology, endocrinology, molecular genetics and developmental factors
what are four components of proximate causation
- hormonal
- neurobiological
- molecular genetic
- developmental
what is the endocrine system
a communication network that influences many aspects of AB
what is the endocrine system composed of
ductless glands that secrete hormones into blood stream (for vertebrates) or surrounding tissue (for invertebrates)
what do endocrine cells do within glands
synthesize and secrete hormones (trigger by internal or external stimuli) that work as chemical messengers to directly or indirectly affect AB
what are the type of hormones and explain them
- protein hormones: soluble in blood
- steroid hormones: non-soluble so require carrier through blood stream.
give example of protein hormone
prolactin
give example of steroid hormone
testosterone
which type of hormone has longer lag time between stimulus and affect on behavior
steroid hormones
explain how the changing of seasoning affects birds endocrine system
as the number of light hours (photoperiod) increases, it triggers an increase in gonadotropin which increases sperm production and testosterone. this increased testosterone increases male aggression and other mating activities (like nest building, mate guarding). the testosterone will bind to receptor cells in the brain to to evoke mating and paternal care.
what can hormones affect
- input systems (sensory systems)
- central nervous system functioning
- output systems (effectors like muscles controlling movement)
how can hormones affect behavior
can modify ongoing behavior (changes to frequency and duration), trigger onset or end of behavior
what is a positive feedback loop
a typical behavior with hormones where an increase in the hormone will cause an increase in something else which in turn will increase hormone production
what type of relationship does testosterone and winning a fight have
positive feedback loop. higher testosterone = increased probability of winning fight
what is the effect of human disturbance on penguins/many animals
when animals are stressed they have high plasma corticosterone and stress hormones levels to trigger anti-predator responses. when super stressed the stress hormones have negative effect (poorer memory and navigation abilities)
for young penguins, even just being exposed to humans through ecotourism groups causes these increases, which causes detrimental effects when they mature
what does vasopressin do
play central role in parental care
what is the difference between male prairie and meadow voles? how does this affect their brains?
prairie voles display parental care while meadow do not
prairie voles have more vasopressin receptors in their ventral pallidum. when these receptors are experimentally increased in meadow voles they display more parental care
