Lecture 5 Flashcards
What are the three male sexual behaviors
Mounting
Intromission
Ejaculation
What is a sex drive
A motivational force that drives individuals to seek sexual Union
What is the appetitive phase of a sex drive
Courtship (includes functions that can comminicate about readiness to mate, genetic endowments, resources, etc.
It can also include search, intrasex and Intersexual competition. Followed by consummatory phase
Describe how male sexual behavior is measured
The intermount interval is the average time between successive mounts
The inter Intromission interval is the average time between successive intermissions
The post ejaculatory interval is the time between ejaculation and the onset of the next copulatory series.
How does castration eliminate or reduce male sexual behavior
- there is mount & Intromission latency
- fewer Intromission
- loss of ejaculation
- decreased number of mounts/ intro missions
Difference between restoration and maintenance
After castration The immediate replacement of testosterone is maintenance and the delayed replacement is restoration.
What maintains mating behavior in castrated males
Testosterone and androstenedione
How does estrogens show a role in male rodent sexual behavior
Estrogens maintains mating behavior in castrated male rodents when male sexual behavior and hormones are blocked.
What is required to maintain normal mating behavior?
Both estrogenic effects and androgenic effects
What is required to maintain normal mating behavior?
Both estrogenic effects and androgenic effects.
Projections from the POA to dopaminergic neurons are necessary for normal male copulatory behavior, explain why
Drugs that increase dopamine levels and doping receptor agonists increase behavior among intact males and drugs that suppress dopamine reduces it.
What kind of organ is vomeronasal organ believed to be.
It’s believed to be a pheromone organ.
What is the flehman response
A response to chemosensory stimuli obtained during anogenital investigation and forced olfactory cues into vomeronasal organ
what is a pheromone?
a chemical produce by an animal and serves as a stimulus to other animals of same species for one or more behavioral responses
Dopamine Pathways - Tuberoinfular pathway
Transmit DA from arcuate nucleus to the Hypothalamus and to the pituitary gland. DA regulates secretion of PRL (prolactin).
DA Pathways - Nigrostriatal Pathway
transmist DA from SN (substantia nigra) to Neostratium. involved in movement and Parkinson’s
DA pathways - Mescorticolimbic pathway
1) Transmits DA from VTA (ventral tegmental area) to frontal lobe of pre-frontal cortex. involved in learning decision making.
2) DA from VTA to NA (nucleus accumbens) involved in motivation, emotion and reward.
3) DA from VTA to Amygdala, NBST, MPOA and Hippocampus. involved in copulatory behavior, social interaction
POA and sexual behavior
Lesion of POA disrupts copulatory behavior
Electrical stimulation of POA accelerates ejaculation
Olfactory stimulus activates the mPOA, increases GnRH resulting in elevated testosterone levels
Modulation of the MPOA
MPOA requieres estrogen for sexual behavior. Castration reduces the production of aromatase in the MPOA which decreases sexual behavior. Testosterone stimulates aromatase and production of estrogen
what are the phases of human sex behavior?
Human sexual behavior can be divided into appetitive (sex drive, libido, motivation) and consummatory (performance, potency) phases.
How do levels of hormones affect male sexual behavior?
In general human male sexual activity parallels circulating levels of androgens. Peak during 20’s and Declines with age. AKA Andropause
What is the role of DHT (Dihydrotestosterone)?
DHT alone does not restore or maintain mating behavior in castrated males but it is required for penile sensitivity in non castrated males.
5 sexual behaviors in which DA is involved?
1) Motivated behaviors 2) Learning
3) Sexual behavior without hormone prime
4) Sexual behavior for non-procreation
5) Sexually naive vs experienced
What primate brain mechanisms are involved?
The steroid receptor distribution is highly conserved in:
-Amygdala -Hippocampus - Hypothalamus
-Forebrain limbic structures
The enzyme distribution differs
Motivation of sexual behavior
It is determined by how much work an individual is willing to do or by how much pain or other unpleasantries an individual can endure to obtain access to a female
