Section A06 - Week 3 Filled

Section A06 - Week 3 Filled - Article Fatal Attraction in...

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Article: Fatal Attraction in Rats Lecture 5: Behavioral Endocrinology I. Hormones – Chemical messages from neurons or glands that influence target organs A) Rhodnius Prolixis – Kissing bug 1) Corpus Allatum: produces juvenile hormone 2) Implanting gland from younger individual results in arrested development; a giant juvenile. 3) Known for spreading the disease Chagas in Panama B) Ecdysone – molting hormone in Gypsy Moths 1) Caterpillar pupates between days 7 – 15 2) Head matures but tail doesn’t when body is severed after day 7 3) Body severed at day 10 , both sides mature 4) Two conclusions: a) Hormone is secreted in the head b) Chemical message sent between day 7 – 10 II. Reproductive Feedback Loops: Ex) Ring Neck Dove Cycle A) Gonadotropins – Produced by the anterior pituitary to act upon gonads to release steroid hormones (male = testosterone / female = progesterone ) 1) Phase 1: Courtship and copulation Photoperiod of Spring plus nest material increases steroid hormone levels (estradiol and testosterone) to influence copulation 2) Phase 2: Nest Building Act of nest building releases progesterone in the female inducing laying of eggs. 3) Phase 3: Egg Laying Prolactin develops during incubation of the egg which develops crop milk while gonadotropins decrease 4) Phase 4: Feeding/Incubation Hatching of the chicks causes prolactin to decrease while gonadotropins rise again to prepare for another cycle B) Subsequent Stimuli are necessary for the cycle to continue from one phase to the next. 1) Introduction of a fake nest stops cycle at phase 1 2) Removal of steroid hormones in females doesn’t allow egg laying 3) Visual stimulation of female egg laying induces prolactin development in males. III. Social stimulation of reproductive biology Ethogram – A record of behavioral activities A) Anole headbob displays: testosterone influenced 1) All female population: 80 % produce vitellogenins 2) All female with 1 male: 100 % v. production 3) Female with multiple male: 30 % v. production 4)Female with castrated male + testosterone: 80 % B) Male plainfin midshipman fish 1) Type 1 Males a) Nest building and egg guarding behavior, large vocal and body structure, neurons larger and fire faster b) Produce 11-ketotestosterone 2) Type 2 Males a) Smaller vocal and body size, no rearing behavior, only produces testosterone b) Overcrowding and environmental stress induce larvae to develop into type 2. IV. Spiny Lizards - eliminating hormones doesn’t always deplete sexual behaviors Casterated males still attempt to occupy territories V. Red-sided Garter Snake A) Disassociated reproductive pattern – Peak gonad activity peaks at a different time of mating B) Male gonad activity, measured by gonad size, peaks in the summer after breeding and is stored until Spring .
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Lecture 6: Behavioral Genetics I. Learned vs. Innate: A continuum of behavioral programs A) Closed program: developmentally fixed and hardwired Example: Lovebirds a) Fisher’s - carry nesting materials in beak
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This note was uploaded on 11/10/2010 for the course BIPN BIPN 102 taught by Professor Fortes during the Spring '09 term at UCSD.

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Section A06 - Week 3 Filled - Article Fatal Attraction in...

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