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Explore how animals organize their priorities and adapt to changing environments through the regulation of behavioral schedules and the role of hormones. Learn about neural command centers, circadian rhythms, and the effects of hormones on behavior.
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5/21/08: Organization of Behavior Lecture objectives: • Develop a proximate understanding for why animals don’t exhibit several behaviors simultaneously • Understand how behavioral schedules are regulated and how they allow animals to meet the demands of a changing environment • Recognize the role that hormones play in eliciting behavioral change
Short-term scale: Neural command centers are responsible for activating a particular response • Center is activated through animal’s - Inhibition: active center can suppress or inhibit other centers- These inhibitory relationships may change b, a, c, d a, c, d, b a b c d
Example: praying mantis nervous system Sex is a “no-brainer” for a male praying mantis
Animals need to modulate behavior to meet the demands of environmental cycles Daily light/dark cycle Lunar cycle Annual cycles: temperature/food supply active/asleep forage/don’t forage Migration, breeding, hibernation How do animals do this?
Do animals track their environment or have an internal clock?
Circadian rhythms likely serve an adaptive function Environment-independent component: Environment-dependent component:
Proximate basis of circadian clock Location: Rhythmic changes in gene activity:
Other behavioral schedules Circannual Lunar, and food-dependent
Hormones play an important role in the organization of behavior Changes in environment Detection by neural centers Translated into hormones Physiological and behavioral changes;i.e. control of reproductive behavior
Hormones and how they work Hormone:
Effects of hormones can be organizational or activational Organizational Hormone action during early development Effects are often Activational Hormone action on tissues Effects are often Female egg Concentration of JH Light feeding Heavy feeding + royal jelly nurse forager
Example: Hormones mediate the effects of mating on the behavioral priorities in male Japanese quail Organizational or activational? Time at window Before mating After mating + T + T + A.I.
Example: Photoperiod alters effects of estrogen (via T)on male beach mouse aggressiveness