Chromosomal sex

Gonadal sex

Hormonal sex

Morphological sex

Behavioral sex

–        Organizational effects

–        Activational effects

•         Hormonal secretions from the developing gonads determine whether the individual develops in the male or female direction

•         The mammalian embryonic testes produce androgens, as well as peptide hormones, that steer the development of the body, central nervous system, and subsequent behavior in the male direction

•         The mammalian embryonic ovaries do not secrete high concentrations of hormones

•         In the presence of ovaries, morphological, neural, and subsequent behavior develops in the female direction

•         The prevailing hypothesis about the initiation of sexual differentiation indicates that the gonads are differentiated by genetic influences (sry gene), and that all other sexual differentiation reflects hormonal mediation. However, it has been suggested that some sex differences in brain and behavior might be mediated directly by genes

a.      First, describe the genetics involved (hint: there is a gene on a particular chromosome that determines whether development proceeds in the male direction)

a.      Second, the presence of this gene causes a structure to develop in the male direction. What is this structure? And what does it do? (hint: it secretes something that affects the developing nervous system and body)

a.      In the absence of the gene, the structure develops in the female direction. What is this structure and what does it do?

  Describe how the accessory sex organs develop in either the male or female direction. (hint: mention the Wolffian and Mullerian ducts, in addition to a protein hormone called MIH).

• Accessory sex organs connect the gonads to the outside environment

The müllerian duct system develops into the female accessory organs; This occurs by default. MIH prevents the Müllerian duct from developing into female internal genitalia (this occurs in males)

The Wolffian duct system develops into the male accessory sex organs; this requires testosterone (T). In the absence of T, the Wolffian duct regresses (this occurs in females)

Because these two primordial systems are present early during ontogeny, it is possible for both systems to develop in a single individual

Where is the SDN located in the brain? 

4.      How do steroid hormones affect behavior?

They do not cause behaviors to occur. Steroid hormones activate certain genes in neurons. Activation of genes can lead to: increase or decrease in the number of neurotransmitter receptors, changing the presence or amounts of enzymes that affect neurotransmitter production (these changes directly affect behavior)

Example: Estradiol facilitates male sexual behavior by promoting activity (e.g., dopamine neurotransmission) in various components of the neural circuits that regulates male sexual behavior

Sexual behavior in female rodents is highly dependent on sex hormones. In fact, sexual behavior is restricted to a particular phase of the ovarian cycle. Females that are sexually active are said to be in behavior estrous. Describe behavioral estrous.

Seek out males

Initiate/permit copulation

Remain in close proximity to male

Is the HPG axis active in males or females or both?

4.   Which hormones are released by the anterior pituitary? Posterior pituitary? 

Follicle stimulating hormone.

Oxytocin and estradial prolactin.

4.   Describe the hormonal correlates of the female cycle. (Note: describe how the brain controls the release of hormones from the ovaries; also discuss the process of negative and positive feedback)

Hypothalamus secretes pulses of releasing hormones

These hormones stimulate the release of gonadotropins from the anterior pituitary

Pulses of gonadotropins drive the release of sex steroid hormones by the gonads

As sex steroid hormone concentrations increase, secretion of gonadotropins is reduced (negative feedback), which results in decreases in gonadotropin-stimulated steroid hormone synthesis

Castration effect: removal of the ovaries (ovariectomy) results in sustained elevated gonadotropin concentrations, as well as elevated releasing hormone secretion (removal of negative feedback)

Why is this surge (GnHP) important for female reproduction?

Which area of the brain is critical for female sexual behavior?

4.      Which area of the brain is critical for female sexual behavior?

Reproductive effort can be divided into mating effort and parental effort. Describe common mammalian sex differences in reproductive effort. (hint: organisms put more effort into the type of effort that maximizes their reproductive success)

Which area of the brain is important for the expression of parental behavior?

 Estrogen facilitates maternal behavior, in part, by enhancing activity of three hormones. Name these hormones. 

1. Which brain system in the brain is involved in maternal behavior—it’s important for motivation and maternal memory?

They influence behavior.

no 

1. Feelings are associated with physiological arousal. What does this mean? (hint: think stress/emotional response)
   

1. What is the James-Lange theory? (Note: discuss how you get from a stimulus to arousal and subjective emotional experience; describe the series of events)
   
   

“I experience fear because I run away, i.e., my feelings are aroused by my actions.”

Cognitive awareness is separate

brain can categorize events as pleasant or unpleasant as quickly as 120 ms

Series of events:

Individual responds to stimulus

Perception leads to action & autonomic activation

Arousal and actions lead to feeling aspect of emotion

1. Which system in the brain is important for emotions? (hint: this system is made up of multiple subcortical structures; we’ve discussed it in class numerous times)
   

1. Is emotional information processes differently by each hemisphere?
   

1. What is the behavioral activation system? Behavioral inhibition system?
   
   

Low autonomic arousal

Stimulates approach behaviors (happiness or anger)

Behavioral Inhibition System (BIS): associated with activity of the right hemisphere (frontal & temporal regions)

Increases attention and arousal

Inhibits actions

Stimulates fear and disgust

1. Which neurotransmitter is involved in aggressive behavior? Describe its role in aggression. (Note: mention how different levels of serotonin affect aggressive behavior)
   

1. What is fear? Anxiety?
   
   

Anxiety is a general sense that something dangerous might occur

1. Which area of the brain is involved in generating a fear response?
   

1. What are the effects on behavior of amygdala damage in monkeys?
   

1. What are the effects on social judgment of amygdala damage in humans? What are some other effects of amygdala damage on processing emotional information?
   

1. What is stress according to Hans Selye?
   

1. How does the body respond to stress? What did Selye call the body’s response to stress?
   

1. Describe the three stages of this response.
   
   

Resistance stage: SNS activity decreases,; adrenal cortex secretes cortisol and other

Exhaustion stage: individual is tired, inactive, and vulnerable because the nervous system and immune systems have little energy

1. What is the HPA axis? This axis is made up of various structures; how do they communication with each other (is it paracrine or endocrine communication)? What activates this axis?
   

Hypothalamus makes CRH à Pituitary makes ACTH adrenal secretes cortisol à increase in blood sugar & metabolism

Activated w/ prolonged stressors

Beneficial in the short-term; detrimental in the long-term

Endocrine system.

1. Is activation of this axis beneficial or detrimental to our health? Which hormones are released during the stress response? Describe the effects of a prolonged activation of this axis? (Note: make sure to describe the effects of a prolonged increase in the major stress hormone)
   

Avoidance of reminders of event

Exaggerated arousal in response to noises, other stimuli

1. Which area of the brain is responsive to cortisol? In fact, high levels of cortisol can damage neurons in this structure. (hint: it is involved in memory and it is smaller in people who suffer from PTSD)
   

1.      What is learning? Memory?

Memory: storage and retrieval of information

Episodic memory:

 Procedural memory:

Implicit memory:

Priming?

Consolidation:

1.      Which area of the brain is important for working memory?

1.      Describe the role of the hippocampus in learning and memory? Where is this structure located? (Note: describe the role of the hippocampus in the different types of memory—e.g., declarative, explicit, spatial, configural, implicit, and any others mentioned in the textbook; also go over the effects of hippocampal damage on patient HM)

true for H.M.

monkeys with damage are impaired in delayed matching (or non-matching) to sample task

but performs well if task always uses same objects

rats with damage have difficulty in learning correct temporal sequence for reward

1.      What is a Hebbian synapse?

1.      Describe LTP in the hippocampus. LTP depends on changes at synapses. Describe these changes. (Note: define/describe AMPA receptors and NMDA receptors)

1.      Most of the changes associated with LTP take place in the postsynaptic neuron. Does that mean that there are no changes at the presynaptic level? (hint: what is a retrograde transmitter?)

increases presynaptic release of neurotransmitter and production of GAP-43, facilitating growth of axons

learning is decreased

learning is facilitated 

1.      What is a split-brain procedure? Describe some of the behaviors displayed by a split-brain patient shortly after the procedure.

1.      What is epilepsy? What causes epilepsy? What is a focus?

1.      Describe hemispheric specializations. What is lateralization? Which hemisphere is dominant for recognizing emotions in others? Which hemisphere is important for language?

Right hemisphere is dominant for recognizing emotions in others

1.      What is the planum temporale and where is it located?

1.      What is Broca’s Aphasia? Wernicke’s Aphasia?

1.      Kinetic energy:

Potential energy:

Ion:

Cations:

1.      What causes the massive depolarization that occurs during an action potential?

1.      During an action potential, what must occur to hyperpolarize the cell and bring it back to its resting potential?

1.      Describe the forces acting on sodium (Na+) and potassium (K+) ions.

                K+ is 20x greater inside

1. What is a synapse? What is the name of a cell that transmits a signal to another cell? What is the name of the cell that receives information?
   

1. What is bulimia nervosa?

1. How is bulimia similar to drug addiction?

1. In one experiment, rats were food deprived for 12 hours a day and then offered a solution of glucose. How did food deprivation affect feeding behavior in these rats?

1. Is dopamine involved in other behaviors?

1. What do all addictive substances have in common 

1. Olds and Milner conducted a few experiments showing that rats will press a lever for electrical stimulation of various areas of the brain. What do all of these areas have in common?
   Why would a rat press the lever as often as 2000 times per hour?

– they release dopamine in the nucleus accumbens

– to stimulate the release of dopamine in the brain, it is very rewarding

1. What is tolerance? -

1. Although many motivated behaviors that are pleasurable activate dopamine systems in the brain, other behaviors that do not provide joy also activate these same dopamine systems. What accounts for the fact that drug addicts continue to engage in drug seeking behavior even though the drug no longer provides pleasure? 

1. Can stress have an effect on a rat’s response to cocaine?

1. Corticosterone is a type of glucocorticoid (stress hormone) in rats. Humans have another type of glucocorticoid called cortisol. In one experiment, researchers treated rats with an injection of corticosterone. Describe the effects of corticosterone on self administration to cocaine in rats.