Geneer Dysphoria, Sexual Dysfunctioning, & Paraphilias

Question 1

Contrast sex and gender

Answer 1

Sex
• Defined by characteristics encoded in DNA
• Two kinds: male or female

Gender
• Social, cultural, and psychological traits linked to human males and females through social context

Question 2

What are the sources of sex differences?

Answer 2

Genetic: Every neuron, glia, or other cell type carries either the complement of male chromosomes (XY) or female chromosomes (XX), but not both

• Hormonal: Differential effects of ovarian and testicular hormones

Question 3

What are the classifications of sex differences?

Answer 3

• Sexual Dimorphism: Endpoint consists of 2 forms (one form in males, another in females)
– copulatory behavior, bird song

• Sex Differences: Endpoint exists on a continuum and average is different between males and females
– pain thresholds, fear, anxiety, learning, memory

• Sex Convergence: Endpoint is the same but neural underpinnings are different
– parental behavior, problem-solving strategies

Question 4

What are the male based sex conditions of CNS disorders?

Answer 4

Male-biased conditions
• ADHD 10:1
• Autism Spectrum Disorder 4:1
• Dyslexia 3.5:1
• Tourette Syndrome 3:1

• Higher frequency of developmental onset disorders in males and adult-onset disorders in females

Question 5

What are the female biased conditions of CNS?

Answer 5

Female-biased conditions
• Anorexia 13:1
• Autoimmune Disorders 3:1
• Depression 2:1
• Anxiety Disorder 2:1

Question 6

What are the frequencies of diseases of the Nervous System in Males and Females?

Answer 6

Quite a number of disease processes of the nervous system are not distributed equally between the sexes. Some of the disease processes are more likely to affect males, others females.

For example: the majority of all patients (75%) suffering from Sydenham’s chorea (a neurological movement disorder characterized by irregular, abrupt, relatively rapid involuntary movements [chorea] of muscles of the face, neck, trunk, and arms and legs) is female.

On the other hand, only 1 out of 10 patients (10%) suffering from Tourette’s syndrome (a neurobehavioral disorder characterized by sudden, involuntary, repetitive muscle movements [motor tics] and vocalizations [vocal tics]) is female, whereas the majority of patients suffering from this disease is male (90%).

These sex differences in the frequencies of disease processes of the nervous system strongly indicate different levels of vulnerability for different types of disorders. They further suggest the presence of differences in structural and functional characteristics of the nervous system between males and females

Question 7

The hormonal environment of adult females is cyclic, the one of adult mal3s is acyclic…

Answer 7

• Another example of sexual dimorphisms in the human brain is the hormonal environment. The hormonal environment is controlled largely by the hypothalamus.

The hypothalamus controls the secretion of gonadotrophins (luteinizing hormone, LH, and follicle-stimulating hormone, FSH) from the endocrine cells of the anterior pituitary, which in turn influence the endocrine activity of the gonads. In females, cyclic variations in LH and FSH levels are responsible for the periodic changes during the menstrual cycle.

• In the male endocrine and neuroendocrine system, the variations in hormonal concentrations are very limited. Apart from dramatic changes of hormone concentrations during certain stages of development, such as puberty, the hormonal environment of males is much more constant, and hence described as acyclic.

Question 8

How are replicable are sex differences in cognitive tasks?

Answer 8

Visual rotation advantage in males

• Language, reading, verbal fluency advantage in females
• How much are these biases driven by current hormonal levels?

Question 9

Contrast the sexual dimorphism nucleus in men to women

Answer 9

Question 10

What are the sex differences between Suprachiasmatic Nuclei of the hypothalamus ?

Answer 10

Question 11

Where are the sexually dimorphism areas located?

Answer 11

Question 12

What are the sexually dimorphism areas of the hypothalamus?

Answer 12

Question 13

What is the human mosaic of sexual differentiation ?

Answer 13

Question 14

What is gender identity?

Answer 14

One’s sense of oneself as male, female, transgender, or gender non- conforming

Question 15

What is a transgender?

Answer 15

Gender identity and biological sex are not congruent

Question 16

What is sexual orientation?

Answer 16

Enduring pattern of emotional, romantic, and/or sexual attractions to men, women, or both sexes

Question 17

What’s the significance of INAH-3

Answer 17

INAH-3 is larger in males than in females

INAH-3 and sexual orientation?

• marker for sexual orientation
• smaller in homosexual than in heterosexual men - same size in women and in homosexual men

Bed Nucleus Stria Terminalis (BNST): males > females

INAH-3, BNST, and Gender Identity

• marker for gender identity?
• smaller in transgender persons (m to f) than in males
• similar size in transgender persons (m to f) as in females

Question 18

What is the role of SRY?

Answer 18

Question 19

What is the role of sex hormones in sexual hormones?

Answer 19

Question 20

Describe the molecular mechanism of testerone action

Answer 20

Question 21

What causes Androgen Insensitivity Syndrome ?

Answer 21

Androgen insensitivity syndrome (AIS) is caused by a mutation in the gene that produces androgen receptors

Question 22

Describe Androgen Insensitivity Syndrome

Answer 22

Androgen insensitivity syndrome is a genetic (X linked, recessive) disease process. In genetic males (XY), the SRY gene is normally expressed and testes develop, although they remain within the body cavity. Due to a mutated androgen receptor, testosterone produced by testicular Leydig cells has no effect on sexual differentiation. In these individuals, phenotype expression and gender identity is typically female.

Individuals with androgen insensitivity syndrome (complete androgen insensitivity syndrome is also called “testicular feminization”) have normal female external genitalia. They are typically recognized at the time of puberty, when they present with primary amenorrhea and sparse-to-absent development of pubic or axillary hair. They develop female breasts and body shape (female-specific distribution of adipose tissue).

Gender identity and sexual orientation have the characteristics of typical genetic females (XX genotype). They prefer to act and dress like women and are sexually oriented towards males

Question 23

What is the critical Period of sexual dysfunction ?

Answer 23

Similar to other developmental processes, sexual differentiation does not occur at any time of life but can happen during only a certain time window called critical period.

In the case of sexual differentiation in humans, the critical period of sexual differentiation occurs prior to birth, during 12 and 20 weeks of gestation. Sexual differentiation during this time window is the result of testosterone secretion, which has a peak in male fetuses during this time period. There is no comparable natural rise in sex hormone levels (neither testosterone, nor estradiol) in female fetuses during the same time period.

The corresponding sensitivity of the reproductive tract and the brain to the elevated levels of circulating testosterone during the critical period of sexual differentiation leads to permanent structural and functional differentiation of body and brain into male phenotypes.

Elevated testosterone levels later during development, which occur during puberty, no longer have such a dramatic potential of sexual differentiation.

They contribute only to relatively minor changes called secondary sex characteristics, which include the development of beard growth in male individuals.

Question 24

What was the effect of experimental DES exposure in rats?

Answer 24

• Normal: SDN larger in males than in females.
• Experiment: SDN larger in DES treated females than in female controls (DES also blunted luteinizing hormone secretion).
• Conclusion: DES exposure during the critical period of sexual differentiation of the brain causes masculinization of the brain.