W1: Neural & Hormonal Control of Behavior

Question 1

How do animals evaluate potential information?

Answer 1

They extract information from the environment through stimulus filtering which reduces the plethora of stimuli to a biologically-relevant suset.
i.e.
electromagnetic, infrared, UV, infrasound, detectable, US

Question 2

What structures make up nervous system that detects sensory input?

Answer 2

• Neurons: make binary decisions
• Axons:transmit action potential to next cell
• Sensory receptors: convert extermal stimuli into electrical impulses (aka sensory transduction)
• interneurons
• motor neruons

Question 3

Explain the bat vs. noctuid moth relationship

Answer 3

• moths must forage and evade predation by bats
• bats eat moths
• co-evolutionary arms race

Question 4

Bat sensory system

Answer 4

2 ultra sonic cries:

• slow = food location and orientation
• fast = attacking moth

2 sensory receptors:

• A1: moderate US
• A2: high intensity US

Question 5

How do moth’s locate bats?

Answer 5

A1 cells fire at moderate intensity permitting detection at 30 meters.
Firing rate related to loudness related to distance.

• Left/right location determined by differential firing rate on different sides of the moth’s body.
• Above/below location determined by steadiness of sound.

Question 6

How does a moth evade an attack?

Answer 6

Avoidance: mother should move around until they hear a constant sound that gets softer.

• A2 receptors fire what attack is imminent
• A2 firing is connected to wings and leads to a wing flip followed by a dive
• if moth survives, it orients and uses A1 to avoid the bat

Question 7

What is the biologically-meaningful stimuli that crickets use to fight rivals, mate, avoid predation?

Answer 7

low frequency sound

Question 8

How do scientists study the evolution of brain function?

Answer 8

Look at hippocampus and spatial memory (i.e. food storing)

-dissect, stain, measure volume of nuclei and entire parts of he brain and compare among species and experience level.

Question 9

What biological structure increases as a function of food storing experience?

Answer 9

Hippocampus

Question 10

Methods for studying specialization of brain function:

Answer 10

• single unit recording
• neurosurgery
• brain damage studies
• MRI

Question 11

Coritcal Magnification

Answer 11

Similar to humunculus.

Describes how many neurons in an area of the visual cortex are ‘responsible’ for processing a stimulus of a given size.

Question 12

Hormones

Answer 12

internal secretions which occur in small quantities in the blood and act as chemical messengers. They typically exart their influence at some distance from the source and because they are blood born, they can have diverse effects.

Question 13

Organizational effects of hormones

Answer 13

act during development to prepare for later use

Question 14

Activational effects of hormones

Answer 14

act to stimulate or modulate behavior in the here and now.

Question 15

What are 3 ways scientists can demonstrate hormone function?

Answer 15

1) show correlations between hormonal levels and size of glands or behavior
2) Remove the hormone and eliminate behavior/trait
3) Re-instate the hormone and restore behavior/trait

Question 16

Activational effects of hormones

Diagram

Answer 16

Physical + Social Environment
              >
Hormonal Changes
              >
Behavioral Changes

Question 17

Prostaglandin

Answer 17

released after genital stimulation. Has a rapid effect of reducing interest in copulation.