Exam 3 Brain Behavior

9-12

Circadian Rhythms

Internal cycle of activity that takes about 24 hrs

Diurnal

Awake in the day, asleep at night

Nocturnal

Awake at night, asleep during the day

Crepuscular

Active during dusk and dawn

Zeitgeber

Time keeper, info about time of day from light, temperature, or clocks

Suprachiasmatic Nucleus

biological clock, direct connection to optic nerve, activates LS

How is melatonin produced

Info from SCN says its dark, info to PG

Polysomnography

Sleep research and diagnosing sleep disorders

What do the three main measurements measure (EOG)

Electrical potential from eyes, track eye movement

What do the three main measurements measure (EMG)

electrical potential from muscle, track facial movement

What do the three main measurements measure (EEG)

neural activity of cerebral cortex, shows stages of sleep

Characteristics of sleep stages throughout the night (Awake)

Beta (dyssynchronous) alpha (relaxed)

Characteristics of sleep stages throughout the night (Asleep S1)

Theta waves- more synced, transition between wakefulness and sleep

Characteristics of sleep stages throughout the night (Asleep S2)

Sleep spindles (bursts of synced waves), memory consolidation, k-complex (triggered by noise)

Characteristics of sleep stages throughout the night (Asleep S3)

Delta activity 25 mins after falling asleep, large synced waves, little eye and muscle movement, lowest level of consciousness

Characteristics of sleep stages throughout the night (Asleep S4)

REM sleep, desynced brain, activity looks like you’re awake, muscles are paralyzed

What unique motor behavior occurs during REM sleep

Muscles are paralyzed except for eyes, which move around

Ventrolateral Preoptic Nucleus of the Hypothalamus (VLPO)

Produces GABA- inhibits wakefulness

Raphe Nuclei

Produces serotonin, communicates w/ cerebral cortex

Adenosine

engaged with high levels of metabolic activity, produced when awake, inhibits sleep

How does Adenosin accumulate?

More is produced when you are awake, making you more and more tired

How does Adenosine caffeine impact it?

Counteracts it

Activation Synthesis Hypothesis

Dreams have no deeper meaning, are a biproduct of arousal of hippocampus and cerebral cortex

Obstructive Sleep Apnea

Airway is blocked by muscles in the throat (relaxed, do not let air pass)

Central Sleep Apnea

CNS fails to tell the body to breathe

Homeostasis

Body maintaining balance

Negative Feedback Loop

Effects of regulatory system slow down or stop feedback (sweating, shivering)

Allostasis

Anticipating physiological needs rather than reacting to them (takes a physical toll on body, moves set point)

Glucose

Creates energy. Muscle tissues break down fat when there isn’t any. Body can function without it but the brain cannot.

Glycogen

glucose is converted into this because glucose cannot be stored

How are insulin and glucagon involved

Insulin converts glucose > glycogen

Glycogen > glucose using glucagon

What produces these hormones (Insulin & Glucagon)?

Pancreas

Cholecystokinin (CCK)

Feeling full as soon as we eat something with fat in it

What brain structure is most involved in various aspects of homeostasis?

Hypothalamus

Lateral Hypothalamus

Stimulated= start eating (feeding center)

Ventromedial Hypothalamus

Stimulated= stop eating

Ghrelin

thinking about when to eat, increases with fasting, decreases with eating

Leptin

Secreted by fat cells, regulates food intake, decreases with hunger

Organum Vasculosum of the Lamina Terminalis (OVLT)

detects water and salt concentration

Preoptic Area of the Hypothalamus (POA)

Maintains thermoregulation

What do endocrine glands secrete?

Hormones

Pituitary Gland

below the thalamus, anterior and posterior lobe “master gland”

Sexual Dimorphism

Sexes have different physical characteristics

Primary Sex Characteristics

Genitals

Secondary Sex Characteristics

Breasts, Adam’s apple

Brain differences (men)

10% larger, stronger front to back connections, optimized motor skills

Brain differences (women)

stronger side to side differences, optimized for intuitive thinking, more grey matter

Mullerian Systems/Ducts

Female genetics

Wolffian Systems/Ducts

Male genetics

Oxytocin

When in females- mate for life

Males- no effect

Vasopressin and Voles

When in males- want to mate for life

Females before mating- did not want to mate anymore

What causes masculinization of the brain

Androgens

Intersex

male born w/ female characteristics or vise versa

Congenital Adrenal Hyperplasia (CAH)

XX, Ambiguous sexual characteristics, earlier puberty, deeper voice, more acne, shorter, facial hair

James-Lange Theory of emotion

Emotion arises from physiological arousal (Not crying bc you’re sad, sad bc you’re crying)

Cannon-Bard theory of emotion

Physiological arousal and emotional experience happens @ same time but seperately

Schachter-Singer theory of emotion

Focused on cognition, emotions = physiological & cognitive response

Ventromedial Prefrontal Cortex (vmPFC)

Gut feeling

Role the amygdala plays in emotion

detect and process fear, collection of nuclei

Behavior associated with Periaqueductal Gray (PAG)

aggressive behavior

Distress

bad stress

Eustress

good stress

SAM System (Functional differences)

Fast stress response, like a match

HPA Axis (Functional differences)

Slower acting stress response, like a bonfire

HPA Axis (Pathway)

Hypothalamus > Pituitary > ACTH > Adrenal Cortex > Gluccocortiroid > CORTISOL

Glucocorticoids

Create cortisol

Adverse Childhood Experiences (ACEs)

Track and see impact (long term) of childhood trauma