pt6 Hormonal Basis of Behavior

endocrine glands

responsible for the secretion of hormones

“ductless glands

Amine Hormones

made up of amino acids.

two subgroups: monoamine hormones and peptide hormoes

monoamine hormones

derived from single amino acid such as tyrosine, phenylalanine, & tryptophan

peptide hormones

consist of chains of amino acids.

long chains = protein hormones

long chains + carbohydrates = glycoprotein hormones

Steroid Hormones

derived from cholesterol

Organizational Effects

effects of steroid hormones that occur early in life and are permanent.

involve structural changes

Activational Effects

effects of steroid hormones that occur in adult life and are temporary.

stimulate mating behavior

Case Study: Precopulatory Behavior in Female Rats

Female rats showing males that they are sexually receptive

Key terms: Estrogen, Progesterone

Estrogen

1) increases willingness to approach male

2) enhance attractivity of female

3) primes for progesterone

Progesterone

1) stimulates sexual receptivity in female

2) prolonged secretion inhibits sexual receptivity

Interventional Studies

studies where the researcher manipulates the hormones of an animal and observes the behavioral changes which may result

• most common technique is to remove endocrine organ

ex - Anole lizards sexual display

Antihormones

chemicals that can temporarily turn off actions of specific hormones

Correlational Studies

determine whether or not two variables are correlated. This means to study whether an increase or decrease in one variable corresponds to an increase or decrease in the other variable.

ex: red deer

• increased test = decreased immune system

Relative Plasticity Hypothesis

developed by Michael Moore

states that alternate phenotypes that are developmentally fixed are due to organizational effects while those alternate phenotypes that are developmentally plastic are due to activational effects.

Associated Reproductive Pattern

animals show a close temporal relationship between gonadal activity and mating.

Dissociated Reproductive Pattern

mating behavior does not correspond with an increase in gonadal activity.

ex - red sided snakes

Constant Reproductive Patterns

species maintain a fairly constant state of gonadal activity.

These animals live in environments are harsh for most of the year. Suitable breeding conditions are unpredictable and occur suddenly

Scent Marking

strategic act using secretions for conspecific communication.

a] These scents can come from specialized scent glands, urine, or feces.

b] used to convey info such as age, fitness, reproductive state, and mark territory

Migration

long-distance movement usually on seasonal basis. migration sometimes is for mating season

ex - Atlantic salmon

Parr Stage

5cm in size. Positive rheotaxis = oriented upstream

Smoltification

physiological and hormonal changes that prep salmon for ocean

• osmoregulation

• coloration changes

• changes in rheotaxis

Smolt

15cm in size. Negative rheotaxis = facing downstream towards ocean

Growth hormone

works to cause tolaerance for sea water

prolactin

Promotes osmoregulation in freshwater for fish. it is inhibited during Smoltification.

controls parental behaviors in birds

cortisol

help with acclimatization

thyroid hormone

responsible for color changes