Lecture 1- Introduction

Question 1

What hormone is produced by the testes and adrenal glands and is linked to aggression?

Answer 1

Testosterone

Testosterone influences the amygdala and prefrontal cortex, leading to increased aggression and risk-taking behaviors.

Question 2

How does increased testosterone affect behavior?

Answer 2

Heightened aggression, risk-taking, and competitive behaviors

This effect is especially pronounced when serotonin levels are low.

Question 3

What sensory system involvement is heightened by testosterone?

Answer 3

Sensory sensitivity (e.g., visual or auditory processing of competitive cues)

This prepares individuals for social dominance interactions.

Question 4

What is the mechanism of oxytocin?

Answer 4

Released by the posterior pituitary gland into the bloodstream

Oxytocin acts on the limbic system, particularly the amygdala and hypothalamus.

Question 5

What behavioral outcomes are associated with oxytocin?

Answer 5

Promotion of trust, empathy, and bonding

This is especially significant during childbirth, breastfeeding, and social interactions.

Question 6

How does tactile stimulation during breastfeeding relate to oxytocin?

Answer 6

It signals the release of oxytocin, strengthening mother-infant bonding

This enhances caregiving behaviors.

Question 7

What is the mechanism by which exercise affects endorphins?

Answer 7

Stimulates the hypothalamus to release endorphins and signals the adrenal glands to release cortisol and adrenaline

This response promotes a feeling of well-being.

Question 8

What is the behavioral outcome of endorphin release during exercise?

Answer 8

Reduction of stress and promotion of a feeling of well-being

Proprioceptive input from muscle movements informs the brain of physical exertion.

Question 9

What activates cortisol release in response to social stress?

Answer 9

Social rejection or competition activating the hypothalamus

This leads to the secretion of corticotropin-releasing hormones (CRH).

Question 10

What are the effects of high cortisol levels?

Answer 10

Increased alertness and preparation to cope with stress

Sensory cues can amplify stress responses and cortisol release.

Question 11

What are endocrine-disruptive chemicals (EDCs)?

Answer 11

Chemicals that mimic hormones and interfere with hormonal signaling

Examples include Bisphenol A (BPA) and Polychlorinated Biphenyls (PCBs).

Question 12

How does Bisphenol A (BPA) affect behavior?

Answer 12

Mimics estrogen and binds to estrogen receptors

Linked to altered reproductive behaviors, such as impaired mating preferences.

Question 13

What was observed in the zebra fish study regarding BPA?

Answer 13

Increased aggression towards other males and altered attraction dynamics

Males become less attracted to females exposed to BPA.

Question 14

What is the mechanism of Polychlorinated Biphenyls (PCBs)?

Answer 14

Mimic thyroid hormones and interfere with their signaling pathways

This can lead to cognitive impairments and delayed sensory-motor integration in children.

Question 15

What sensory system involvement is affected by thyroid hormone disruptions?

Answer 15

Impairment of the maturation of sensory systems like vision and hearing

This affects behavior and cognitive development.

Question 16

True or False: Hormones can cause residual arousal that affects perceptions.

Answer 16

True

For example, the bridge-crossing study showed that crossing a bridge influenced attraction ratings.

Question 17

Fill in the blank: The hormone released during physical touch that promotes bonding is _______.

Answer 17

Oxytocin

Physical touch can stimulate oxytocin release, enhancing social connections.

Question 18

What are hormones

Answer 18

chemical messengers affecting sensory systems, neural integration and behavioral outputs

Question 19

What different sciences is behavioral endocrinology a blend of?

Answer 19

psychology, endocrinology, neuroscience, zoology, genetics, etc

Question 20

What is considered the official launch of behavioral endocrinology (and year)?

Answer 20

1967: Launch of the journal “Hormones and behavior”

1996: Creation of the Society for Behavioral Neuroendocrinology

Question 21

What did Aristotle’s descriptions of castration effects contribute to?

Answer 21

Early understandings of the relationship between biological structures, hormones, and behavior

Question 22

[Aristotle] What physical traits did castrated roosters (capons) fail to develop?

Answer 22

Typical traits such as combs, wattles, or spurs
Lacked the vibrant plumage and size associated with intact male roosters

Question 23

[Aristotle] What behavioral changes were observed in castrated roosters?

Answer 23

Less aggressive, did not engage in territorial fights or crowing

Question 24

[Aristotle] What sexual behavior changes were noted in castrated roosters?

Answer 24

Reduced or no sexual behavior toward hens

Question 25

[Aristotle] What physical changes did Aristotle note in castrated men (eunuchs)?

Answer 25

Lack of facial hair and a higher-pitched voice

Question 26

[Aristotle] What behavioral tendencies did castrated men exhibit compared to non-castrated men?

Answer 26

Decrease in aggressive tendencies and sexual behavior

Question 27

What conclusion did Aristotle reach regarding the role of testes?

Answer 27

Testes played a significant role in influencing physical traits and behaviors associated with masculinity

Question 28

Who conducted the first formal study of endocrinology?

Answer 28

Arnold Adolph Berthold ## Footnote The study was conducted in 1849, and was initially overlooked (no sct attention for 60y)

Question 29

What was the main finding of Berthold’s experiment?

Answer 29

Substances produced by the testes travel through the bloodstream to influence behavior. ## Footnote The SUBSTANCE matters

Question 30

What significant fields did Berthold’s experiment mark the beginning of?

Answer 30

Endocrinology and behavioral endocrinology.

Question 31

Describe the 3 groups used in Berthold's experiment and decribe what happened to each.

Answer 31

**Group 1: Both testes removed (castration)** * Result: Birds developed as capons with no crowing, mating, or aggression. * Physical changes: Small bodies, pale and underdeveloped combs and wattles **Group 2: One testis reimplanted into the bird's abdominal cavity** * Result: Normal male development and behaviors (crowing, fighting, mating). * Testis developed vascular connections and functioned normally. **Group 3: Testis transplanted between two birds**. * Result: Both birds developed normal male behaviors and physical traits.

Question 32

What study showed that behavior could be influenced by *internal* biological processes?

Answer 32

Berthold's experiment ## Footnote Highlights the role of hormones in regulating mating, aggression and physical development

Question 33

Who discovered the chemical messenger later called secretin?

Answer 33

William Bayliss and Ernest Starling ## Footnote This discovery was made in 1902 in the duodenum.

Question 34

What significant shift did the discovery of hormones represent in understanding regulation?

Answer 34

nervous system --> chemical signaling ## Footnote This marked the beginning of the field of endocrinology.

Question 35

What was the hypothesis tested by Bayliss and Starling in their experiment?

Answer 35

The digestive tract operates independently of signals from the brain

Question 36

What procedure did Bayliss and Starling use in Experiment 1? What were the results?

Answer 36

**procedure** * Dog anesthetized, small intestine exposed. * Nerves to the intestine severed. * Hydrochloric acid injected into intestine. * Pancreatic secretions collected. **results** * Pancreas released enzymes despite lack of brain or nerve input. * Suggested involvement of a hormone in regulating pancreatic function. ("secretory product") ## Footnote This was done to prevent any signals from the brain and spinal cord.

Question 37

What substance was injected into the exposed section of the small intestine during their experiment?

Answer 37

Hydrochloric acid (HCl)

Question 38

What was the main finding from Experiment 1 regarding pancreatic secretions?

Answer 38

The pancreas released enzymes regardless of brain or nerve input ## Footnote This indicated that something in the intestine triggered the pancreatic response.

Question 39

What term was later used to describe the 'secretory product' involved in regulating pancreatic function?

Answer 39

Hormone

Question 40

True or False: The secretion of digestive enzymes was found to be triggered solely by a direct neural signal.

Answer 40

False

Question 41

What is Bayliss and Starling's main finding

Answer 41

The secretion of digestive enzymes was triggered by a chemical signal from the intestine, rather than a direct neural signal.

Question 42

What procedure did Bayliss and Starling use in Experiment 2? What were the results?

Answer 42

* Bayliss and Starling exposed another dog’s intestine to HCl. * They filtered a substance from the intestine's tissue fluids. * The filtrate also stimulated the pancreas to secrete enzymes. * This confirmed that the signal for digestion originated from the intestines, not the brain

Question 43

How do hormones function?

Answer 43

They travel through the bloodstream to target organs or tissues

Question 44

What roles do hormones play in physiology and behavior?

Answer 44

* Regulate bodily funcitions (ex: metabolism, reproduction) * Coordinate physiological changes with behaviors like mating/activity * Ensures physiology and behavior are synchronized with environmental demands (ex: metabolic hormones increase blood glucose before waking)

Question 45

What is the difference between a hormone and a neurotransmitter?

Answer 45

* Hormones act over longer distances and timeframes * NT work rapidly and locally

Question 46

How are called cells with the specific receptor for a hormone?

Answer 46

Target cells ## Footnote interaction between a hormone and its receptor initiate a series of cellular events

Question 47

Name and describe the three components of animal behavior.

Answer 47

* Input Systems: Sensory systems that detect environmental stimuli * Integrators: The central nervous system (CNS) processes and integrates sensory input. * Output Systems: Effectors (e.g., muscles) that produce behavioral responses

Question 48

What is the hormones' role in animal behavior?

Answer 48

* Hormones do not directly cause behavioral changes * Influence the likelihood of specific behaviors being elicited * Hormones modify the probability that a behavior will occur in response to appropriate stimuli * The influence of hormones is not about causing behavior but making it more likely in the correct situation ## Footnote MODULATION: makes the behavior aligned with environmental demands

Question 49

What happens to singing behavior when the testes are removed in male zebra finches?

Answer 49

Singing behavior is reduced

Question 50

What can restore singing behavior in male zebra finches after testes removal?

Answer 50

Reimplanting testes or providing testosterone or estrogen (estradiol)

Question 51

When are estrogen levels highest in relation to singing behavior in zebra finches?

Answer 51

When singing behavior is most frequent

Question 52

How might estrogens affect sensory capabilities in zebra finches?

Answer 52

Estrogens might enhance the bird's ability to detect relevant environmental stimuli

Question 53

What effect do estrogens have on the central nervous system (CNS) of zebra finches?

Answer 53

Estrogens may affect the neural architecture, improving the processing of sensory inputs Changes in motivation, attention, and perception

Question 54

How might estrogens influence effector organs in Zebra Finch?

Answer 54

Estrogens could influence the muscles controlling vocalization (e.g., syrinx)

Question 55

How might elevated testosterone levels influence an individual's sensitivity to perceived threats or challenges in their environment?

Answer 55

Elevated testosterone levels can increase a person's sensitivity to certain stimuli, making them more likely to interpret neutral or ambiguous situations as threats or challenges. This heightened sensitivity can trigger a quicker, more aggressive response.

Question 56

In what ways can testosterone affect brain areas?

Answer 56

* Testosterone can impact brain areas associated with aggression, such as the amygdala, influencing emotional responses and decision-making * It may also enhance the motivation to assert dominance or compete, increasing the likelihood of aggressive behavior

Question 57

How might testosterone alter a person's effector organs?

Answer 57

Testosterone may affect muscle tone or increase physical readiness for aggressive action (e.g., posture, facial expressions, vocalizations).