Week 5 Flashcards
(46 cards)
1
Q
What is the overall goal of mating?
A
- The passage of genetic material done via the generation of offspring
- If you are not successful sexually you are not successful evolutionarily
2
Q
What are the benefits of having 2 different sexes?
A
- The recombination of genetic material
- Sexual populations can evolve faster than asexual ones
- Also means faster adaptation to a changing environment
3
Q
What are the costs of having 2 different sexes?
A
- Breaking up successful genotypes
- Requires time and energy
- Attention from mate is a mixed blessing
- Attracts predators and parasites
4
Q
What’s parthenogenesis?
A
- Asexual reproduction, growth, and development of embryos in the absence of fertilization
5
Q
What’s hermaphrodism?
A
- Reproductive organs associated with both sexes present in one organism (self-fertilization; can occur in scenarios where the individual cannot find a mate)
6
Q
Protandrous vs. Protogynous?
A
- Both types of sequential hermaphrodites
- Protandrous - The organism is initially male, can turn female
- Protogynous - The organism is initially female, can turn male
- A select group may transition to the opposite sex depending on the demands of the group
7
Q
What’s simultaneous hermaphrodism?
A
- Commonly found in invertebrates (some fish)
- Simultaneous production of sperm and eggs
- Can fertilize and get fertilized at the same time
8
Q
What’s special about leopard slugs?
A
- Hermaphrodites
- They can fertilize their own eggs
- Will partner with other slugs
- Uses gravity to push their fluid into their massive penises, which come out of the sides of their heads
9
Q
Why are females choos when picking a mate?
A
- Must perform a cost/benefit analysis
- Investment vs. genetics
10
Q
What methods can a female use to assess the genetic fitness of potential male suitors?
A
- Intersexual competitions - Preferentially picking one mate over another
- Courtship rituals - A chance to assess the fitness of a potential mate
11
Q
What are the three major stages that occur when mating from the female perspective?
A
- Attractivity = Females visual, auditory, and/or chemical cues that provoke approach behaviour in males (i.e., ear wiggling in female rats)
- Proceptivity - Females approach behaviour in response to contact with a male
- Receptivity - Females capacity to engage in copulation
*There can be variability in these steps
12
Q
What’s an important component to remember about mating from the female perspective?
A
- Females are NOT passive participants in mating, they have an active role
- Females are also much more complicated
13
Q
What are the general differences in sexual behaviour between rats and humans?
A
- Rats: Attractivity and proceptivity lead to receptivity
- Humans: Sexual desire leads to sexual arousal
14
Q
What’s unique about the ovarian cycle in rats?
A
- 4-5 days long, one of the fastest ovarian cycles among mammals
- Estrus - period of sexual receptivity
- Sexual receptivity lasts around 12-20 hours
15
Q
What hormones are involved in sexual receptivity in female rats?
A
- Estrogen promotes initial proceptive behaviour while progesterone enhances it
- They both work to set up engagement in sexual behaviour
16
Q
What are the copulatory interactions that occur between rats?
A
1) Mounting
2) Intromission
3) Ejaculation
17
Q
Why is it important that females control the pace of copulations?
A
- Ensures the neuroendocrine reflex occurs properly
- Also maintains the corpus luteum (i.e., the temporary structure that produces hormones and supports pregnancy)
- This has been tested in the paced mating chamber
18
Q
How has it been tested that females are not passive participants in rat copulation?
A
- Female rats have an odour preference for sexually active males
- Conditioned place preference (light vs. dark)
- Operant conditioning tasks (will bar press for access to a male); will corss an electric grid
19
Q
What female rat behaviours indicate that they are attracted to a male?
A
- Presentation
- Hopping
- Darting
- Ear wiggling
- Vocalizations
20
Q
What are male rat appetitive behaviours?
A
- Behavioural patterns that orient a male toward a female
- Grooming, active investigation
21
Q
What are male rat pre-copulatory behaviours?
A
- Behaviours that reflect motivation toward a specific sexual target, influenced by concurrent sexual arousal (i.e., signalling from the female)
22
Q
What are male rat consummatory behaviours?
A
- Mounting, intromissions (penile-vaginal insertions), and ejaculation
23
Q
Which main brain region is involved in mating for female rats?
A
- The ventromedial hypothalamus
- High density of estrogen and progesterone receptors
23
Q
T/F: Human males follow the same sexual trajectory as male rats
A
- TRUE
- Males just concerned with passing on genetic material
24
What's lordosis?
- A reflexive posture produced when a sexually receptive female is mounted
- A highly conserved behaviour in multiple species
25
What is the resulting behaviour when there is a lesion to the ventromedial hypothalamus? When the ovaries are removed?
- Lesion to VMH = NO LORDOSIS
- OVX = NO LORDOSIS. This is because the VMH requires hormones
- Injection of estrogen to VMH (if ovaries are removed) would restore this behaviour)
25
What's the impact of estrogen in the VMH in female rats?
- Increase the number of dendrites
- Increase progesterone receptors
- VMH monitors levels of estrogen and "gates" lordosis behaviour
26
What's the general diagram of how neural networks mediate mating behaviours in female rats?
VMH > Periaqueductal grey > Medial reticular formation > Spinal cord (spinal cord integrates signals from MRF and male stimulation)
27
What are the main brain regions involved in mating behaviours in male rats?
- Medial preoptic area
- Nucleus accumbens
28
What would happen if the medial Preoptic area (mPOA) was lesioned in a male rat?
- There is a high density of steroid receptors in the mPOA
- Lesion = NO SEXUAL BEHAVIOUR
- Castration = NO SEXUAL BEHAVIOUR
- Injection of androgens to mPOA restores behaviour
29
Integration of what types of information are required for male rats to properly perform sexual behaviour?
- Integration of steroid and sensory info to regulate behaviour
- Allows for better coordination of motor patterns for copulation
30
What's the general diagram of the neural mediation of sexual behaviour in male rats?
- mPOA > Ventral midbrain > Basal ganglia and spinal circuits (receiving stimuli)
- This circuit is clinically important!
31
What's the significance of the basal ganglia in assisting with sexual behaviour in male rats?
- Coordinates motor behaviours and receive info from the cerebellum and substantia nigra
32
Where are the circuits located responsible for mediating ejaculation in rats?
- Spinal circuits
33
What did the double dissociation procedure in lesioning the mPOA and amygdala in male rats when attempting to copulate?
- Lesion to mPOA = Failure to copulate
- Lesion to amygdala = Reduction in motivated behaviour but still able to have sex (just can't be bothered)
34
What's oxytocin?
- "The love hormone"
- Contributes to bonding behaviour in humans
- Especially present in social affiliation, facilitation of approach behaviour (makes mates more attractive), and smooths the way for sexual contact
35
What's significant about the Prairies Voles lifetime monogomy when also looking at their neurophysiology?
- They have very high density of oxytocin receptors in their brains
36
What's the significance of early life experiences?
- They program the individual, altering behaviours later in life
37
What's the adaptive significance of early life experiences in mediating future behaviours?
- Stress immunization - Brief handling of a pup daily in the first week of life leads to smaller stress response later in life
- Adaptive value - Most animals live in the same environment as where they were born
- Developmental programming - Prepares them for this environment (i.e., how mom interacts with you will set you up for success)
38
What's an example of the importance of early life experiences in Bogota, Columbia?
- There was a 70% mortality rate in preterm infants, a shortage of caregivers and a lack of resources
- Solution: People came and cuddled babies
- Immediate outcomes: Increased weight gain, reduced mortality, reduced morbidity
39
What are the benefits of kangaroo care to a newborn baby?
- Thermoregulation
- Stabilizes heart rate, respiration, and oxygenation
- Regulates blood pressure
- Enhances breastfeeding
- Stress reduction
- Promotes quiet, alert state
40
What are the benefits of kangaroo care to the mother?
- Enhances bonding behaviours
- Reduction in post-partum depression
- More likely to breastfeed
- More touching, holding, positive speaking behaviours one year later
- Spike in oxytocin
41
What's another long-term benefit of kangaroo care for newborns?
- Activation of the amygdala via the orbitofrontal pathway
- This can enhance emotional learning, memory modulation, and activation of the sympathetic nervous system
42
What are the benefits of kangaroo care across the first ten years of life?
- Attenuated stress response
- Better sleep
- Better parasympathetic nervous system activity
- Better cognitive control
- Enhanced cognitive development and executive function
43
What are the benefits of kangaroo care on paternal influences?
- Temperature modulation
- Pain sensitivity
- Behavioural responses
- Paternal stress, anxiety
- Bonding behaviours
44
What main functions is the orbitofrontal cortex responsible for?
- Sensory integration
- Decision making
