Lecture 19

Question 1

the extrapyramidal system pathway

Answer 1

basal ganglia gets information from cortex (except primary sensory) project to thalamus and back to cortex.

Question 2

what is the extrapyramidal system modulated by

Answer 2

substantia nigra

Question 3

the extrapyramidal system is used for

Answer 3

initiation, amplitude, and direction of learned movement

Question 4

Cerebellum: input, output, and functions

Answer 4

input: sensory system
output: motor inhibition (perkinje cells)
makes programs for rapid skilled movements, including learning the precise timing

Question 5

muscular distrophy

Answer 5

direct muscle impairment

Question 6

myastheniagravis

Answer 6

auto immune attack on Ach-R

Question 7

parkinson’s

Answer 7

loss of DA neurons in the substantia nigra, affecting DA used at excitatory synapses in basal ganglia

Question 8

amyotrophic lateral sclerosis

Answer 8

motor neurons start dying, leading to muscle atrophy

Question 9

Huntington’s disease

Answer 9

loss of normal inhibition in basal ganglia- extreme uncontrolled movements

Question 10

damage to spinocerebellum

Answer 10

ataxia- degenerative disease of nervous system (coordination based on perception)

Question 11

damage to cerebrocerebellum

Answer 11

decomposition of movement, impaired precision in motor learning

Question 12

damage to vestibulocerebellum

Answer 12

affects posture, coordination of gaze with movement, and balance

Question 13

motor skill learning in rats: reach training

Answer 13

in order to reach through window need to use non dominant hand. learn to do this. wrist and digit areas on non preferred hand expand and new synapses are formed

Question 14

causes of stroke

Answer 14

either a break in the capillaries in the brain or a blood clot that clogs the capillaries. Both cases leads to a patch of brain that doesn’t have the nutrients it needs

Question 15

hermaphrodite

Answer 15

male and female sex organs for both animals

Question 16

appetitive behavior

Answer 16

interested in going further

Question 17

copulation

Answer 17

each participating

Question 18

steroid review

Answer 18

steroid hormones are small, lipophyllic molecules synthesized from cholesterol. easily move between cells and tissues. cannot be stored, released as soon as made, can easily pass from the circulation and into blood brain barrier.

Question 19

testosterone can easily be changed into

Answer 19

DHT (androgen) or E2 (estrogen)

Question 20

organizational effects of hormones

Answer 20

permanent or long lasting effects on behavior, have a critical period early in development, and establish substrate for future behavior

Question 21

activation effects of hormone

Answer 21

temporary and diminish as hormone is metabolized, occur in adulthood, act on established substrate of receptors in tissues and brain

Question 22

What is the development for male sex

Answer 22

Male mammals- male has a Y chromosome, SRV gene is on Y and becomes activated, early differentiation of testes from gonad, production of testosterone, masculinization of brain and body

Question 23

what is the development for female sex

Answer 23

Females- lack of early testosterone leads to development of female gonads, genitalia, and brain circuits.

Question 24

aromatization hypothesis

Answer 24

testicular androgens enter the brain and are converted there into estrogens to masculinize the developing nervous system, separate from effects on body

Question 25

if there is a low amount of s a reductase

Answer 25

may cause baby born without penis

Question 26

development of the body, brain, and behavior in absence of androgens

Answer 26

female (default) regression of wolffian ducts and growth of mullerian into fallopian tubes and uterus

Question 27

development of the body, brain, and behavior in prescence of androgens

Answer 27

male, regression of mullerian ducts and growth of tubes for carrying sperm

Question 28

during fetal development, how does a particular immune cell play a key role in determining male or female characteristics of the brain

Answer 28

fetal males have more mast cells in PoA than females. they release histamine, which induces local microglial to release prostaglandin molecules that in turn stimulate synapse development

Question 29

androgen insensitivity syndrome

Answer 29

(not responsive to androgens) gene for androgen receptor is on the X chromosome. Act and appear female but have testes

Question 30

congenital adrenal hypertrophy (CAH)

Answer 30

adrenal cortex too active, XX plus androgens, act and appear male, but have ovaries

Question 31

XX and exposure to environmental androgens

Answer 31

appear male but also develop ovaries and uterus inside

Question 32

guevedoces

Answer 32

5 alpha reductase deficiency, can't convert testosterone intermediate, raised as girl then shifts in adolescence to male like

Question 33

what hormones are linked to social attachment

Answer 33

oxytocin and vasopressin have been implicated in several forms of affiliative behavior including parental care, grooming, sexual behavior, and pair bonding

Question 34

How are male rats responsive to pheromones/sexual stimulation?

Answer 34

Pheromones from receptive females are detected by the vomeronasal organ. Higher brain center axons converge on mPOH (medial preoptic area in males). Circulating testosterone is converted to estrogens and acts on these 2 sites (mPOA, and medial amygdala). Androgens act on spinal neurons to augment reflexes. Ventral midbrain neurons connect to those associated with ejaculation so those neurons become more likely to be active. From ventral midbrain to brainstem to spinal cord associated with posture of male (mounting)

Question 35

How are female rats responsive to pheromones/ sexual stimulation?

Answer 35

Estrogens induce production of progesterone receptors to respond to that hormone. Estrogen affects neurons at these 2 sites (ventromedial hypothalamus, periaqueductal grey). Periaqueductal grey turns off sensations of pain and turns up sensations of pleasure. Communicates to medullary reticular formation, then goes to the spinal cord involved in lordosis- when the female arches her back to make herself more accessible to the male. Higher brain centers feed into the 2 sites as well and the male stimuli of touching her also stimulates lordosis

Question 36

what structure is critical for female sexual behavior

Answer 36

the ventromedial hypothalamus (VMH)

Question 37

what structure is critical for male sexual behavior

Answer 37

the medial preoptic area (mPOA)

Question 38

phasic hormone shifts in females

Answer 38

causes times that pregnancy is possible and times that pregnancy is not. Can follow an endogenous rhythm like in humans and rats or an external one like day length in deer

Question 39

female reciprocity to copulation may be linked to

Answer 39

tightly to hormone pattern in dogs and horses or loosely linked in great apes

Question 40

what can help explain why autistic kids have difficulty forming a close relationship with someone else

Answer 40

their different oxytocin patterns

Question 41

Difference between human sexual response cycles (orgasms) for males and females?

Answer 41

Males have sexual excitement, hit a minor plateau, then have an orgasm and then a refractory period before they can then be stimulated again for another orgasm. Women can be sexually excited for a long period of time and never reach orgasm, they can be excited fast and reach orgasm fast, or it could be at a medium pace. They don’t have a refractory period before they can be stimulated again

Question 42

what zone differs in between males who are straight and gay

Answer 42

INAH in anterior hippocampus is the same size in homosexual men as in women, but is smaller than straight males

Question 43

Mr. Odonell

Answer 43

behavioral, hormonal, and molecular causes | drinking problem, neurons die in hippocampus, korsakoffs syndrome

Question 44

Henry mokison (HM)

Answer 44

epilepsy, surgery removing front 2 inches of temporal lobe, severe anterograde amnesia for episodic material. Information not retained about where or what, but how could be learned

Question 45

aplysia habituation (what happens, NT, short term v long term)

Answer 45

on being touched the gill and the siphon are withdrawn for some period of time, after repeated stimulation, the withdrawal reflex becomes much smaller. In habituation the axons don't release as much neurotransmitters (glutamate) as a result of altered mobilization of NT vesicles. This is short term habituation that can last several minutes but after repeated habituation the sensory neuron retracts many of the collateral axon branches (can last up to 3 weeks)

Question 46

aplysia sensitization

Answer 46

after shocking the tail, later touches to the siphon produce increased motor response.