Hormones and Behaviour Flashcards
What are hormones?
produced and secreted by endocrine glands and travel through the bloodstream to bind on receptors on cells in the body
Called endocrine signaling
What are neurotransmitters?
Released at a synapse and bind to receptors only nanometers away from the synaptic cleft
• Called synaptic signaling
What were the differences that Berthold noticed in roosters that were castrated and not?
- Change in colour
- Change in mating behaviour
- Change in aggressivity levels
Bayliss and Starling injected HCL in dogs intestines, what were their findings?
It produced secretions from the pancreas, which they called “secretin” and later “hormones”
Name the 5 types of hormones and their functioning
- Intracrine hormone: mediates effects within the cell that synthesized it
- Autocrine hormone: after its release from a cell, binds to receptors on the same cell that released it and regulates its function
- Paracrine hormone: affects cells in the immediate surrounding of the cell that released it
- Ectocrine hormone: released into and organism’s external environment (ex: pheromones)
- Endocrine hormone: released into the bloodstream and affecting surrounding cells
What are the main hormones secretedy by the posterior pituitary?
Oxytocin and ADH(vasopressin)
What are the 2 categories of hormones secreted by the hypothalamus in the anterior pituitary?
Hypothalamic releasing hormones and Hypothalamic inhibiting hormones
Name the 3 Hypothalamic inhibiting hormones
○ Growth hormone-inhibiting hormone (GHIH, AKA somatostatin)
○ Gonadotropin-inhibiting hormone (GnIH)
○ Dopamine (Prolactin-inhibiting hormone PIH)
Name the 5 Hypothalamic releasing hormones
○ Thyrotropin-releasing hormone (TRH)
○ Growth hormone-releasing hormone (GHRH, AKA somatocrinin)
○ Gonadotropin-releasing hormone (GnRH)
○ Corticotropin-releasing hormone (CRH)
○ Prolactin releasing hormone (PRH)
Where are hypothalamic releasing and inhibiting hormones secreted to?
the hypophyseal portal system (connects hypothalamus to anterior pituitary)
hypothalamic releasing and inhibiting hormones in the anterior pituitary result in the secretion or release of which hormones?
□ Thyroid-stimulating hormone (TSH) □ Adrenocorticotropic hormone (ACTH) □ Prolactin (PRL) □ Growth hormone (GH) □ Gonadotropic hormone
How are also called steroid and non-steroid hormones?
peptide hormones or protein-like hormones
Steroid hormones are synthesized from?
Cholesterol
Steroid hormones are produced in (2)?
Adrenal glands and ovaries/testes
Name 2 types of steroid hormones?
- Progesterone
* Testosterone
Name the process by which steroid hormones trigger the synthesis of new proteins by DNA? (3 steps)
- Diffusing through cell membranes
- Binding to receptors within cells
- Entering cell nucleus and binding to DNA
Name 4 nonsteorid hormones?
Norepinephrine
Insulin
Leptin
Ghrelin
Do nonsteroid hormones enter the cell?
No they bind to receptors on the membrane and activate messengers inside the cell
What are anabolic androgenic steroids?
Drugs designed to mimic the muscle building (anabolic) and masculinizing effects (androgenic) of male steroids
What are the side effects of anabolic androgenic steroids?
- Associated with bad side effects (cardiac dysfunction and multiorgan failure)
- Also psychological side effects (depression, mania, mood swings, illicit drug use)
What is roid rage?
increased aggression (loss of impulse control and overreaction to stimuli) happening when taking steroids
WHat are the actions of ADH (vasopressin)?
- Prevents the loss of water (anti-diuretic) when salt is too concentrated in blood plasma (hypertonic plasma)
- Also increases blood pressure by constricting blood vessels
What are the actions of oxytocin?
- Involved in reproductive functions
- Causes contraction of uterus during labor
- Causes milk “letdown” in mothers when nipple is stimulated
What are the actions of thyroid-stimulating hormone (TSH)?
- Induces thyroid gland to release thyroxine
* Maintains body metabolism
* Muscle control
* Brain development
What is hypothyroidism?
not enough thyroxine (brain deficiency and depression)
What is hyperthyroidism?
too much thyroxine (Increase in metabolic system)
What are the actions of adrenocorticotropic hormone (ACTH)?
- Produced in response to corticotropin-releasing hormone (CRH) from hypothalamus
- At the center of the stress response
- Activates HPA axis
- Makes adrenal glands release cortisol - trigger fight/flight
What are the actions of prolactin?
Stimulates milk production
What is adult growth hormone deficiency?
Lack of growth hormone (promoting tissue growth)
can be treated w GH supplement (GH therapy)
What are the 2 types of gonadotropic hormones?
- Lutenizing hormone (LH): stimulates production of estradiol (estrogen)
* Follicle-stimulating hormone (FSH): stimulated growth of ovarian follicles (production of testosterone in men)
WHat is social behaviour, what hormones mediate it?
interspecies mingling that are beneficial to one or + individuals of the species.
• Mediated by oxytocin and vasopressin
What is the social behaviour neural network? ( no need to know all the structures involved)
includes the amygdala, the preoptic area, the anterior hypothalamus, the ventromedial hypothalamus, the periaqueductal gray matter, and the lateral septum
• Thought to underlie the neurobiological basis of social behaviour
What is social recognition? What is it mediated by?
ability to recognize individuals to determine how to act with them (behavioural interactions).
• Mediated by oxytocin and vasopressin receptors in the hippocampus
What were the results of the study comparing soical recognition in mice?
normal mice spend more time with the novel mice than the familiar mice (meaning that it is able to recognize the mice that is familiar)
What is pair bonding?
monogamous relationship between individuals of the same species that leads to reproduction and a lifelong bond.
• Mediated by mainly oxytocin and vasopressin
• Only about 3%-5% of mammals (including humans) are monogamous in nature
What were the results of the experiment injecting oxytocin centrally in paririe voles?
Facilitated a partner preference in female prairie voles
peripheral injections had no effect
What are the roles of vasopressin in social behaviours?
- Opposite of oxytocin
* Nest/territory defending against intruders
What are the differences in the brains of monogamous vs nonmonogamous animals?
- Monogamous = oxytocin receptors concentrated in reward areas (making bonding a favorable thing)
- Nonmonogamous = oxytocin and vasopressin receptors placed differently in their brains
What is parenting?
process that promotes/supports the development of offspring through caregiving
• May include physical, emotional, behavioural, intellectual and social development
When does parenting behaviours start?
- Starts with changes in hormonal levels at pregnancy
* Progesterone and estrogen high during pregnancy
* After/during birth, rise in oxytocin and prolactin
What is the network of parental care in rodents? How does it work?
MPOA + amygdala + dopamine reward pathway
Median preoptic area (MPOA) (hypothalamus)
• MPOA neurons secreting galactine interpret external cues from environment or pups to generate the parental behaviours necessary (grooming, nesting, etc) and suppresses behaviours competing with parenting
What is the difference in parenting behaviour of humans compared to rodents?
- Patterns are similar, BUT humans can regulate their behaviour to adjust to their child, learn to read non-verbal cues from their child, etc
- In short, humans is not only driven by stimuli eliciting reflexes, it is also driven by conscious thinking and emotion regulating
What is reproductive behaviour?
any behavioural pattern that results in sperm and egg being brought together to produce offspring
What is sexual behaviour?
a component of reproductive behaviour that includes responses directly associated with genital stimulation and copulation
What are the 4 stages of female reproductive behaviour in rodents?
- vaginal estrus
- diestrus I
- diestrus II
- vaginal proestrus
What is behavioural estrus?
corresponds to vaginal proestrus, when an egg is released (period when females can mate)
What is receptivity?
actions performed by a female that are necessary for copulation
When can males reproduce? What is the main eliciting stimulus?
At any time; they are aroused by the pheromones released by females in estrus
What is the menstrual cycle?
Change in ovaries
What is the uterine cycle?
Changes in endometrium
Driven by steroid hormones produced in ovarian cycle
What pathway will the pheromones of women elicit in males?
- Activate vomeronasal pathway (part of the olfactory system)
- Info from olfactory system and somatosensory stimulation of genitals is processed in amygdala and sent to the MPOA, where dopamine will be released and create motivation to engage in reproductive behaviour
- Testosterone: facilitates dopamine release in MPOA
WHat are the 2 phases of the ovarian cycle?
- Follicular phase (release of FSH (follicle-stimulating hormone) and LH (lutenizing hormone) from anterior pituitary)
- FSH L triggers release of estrogen from follicles
- LH: releases androgens and are converted to estrogens
- Peak in estrogen triggers the hypothalamus to stop releasing GnRH (pituitary stops)
- Copus luteum develops in the ovary and releases progesterone to support pregnancy if it occurs
- Lutear phase after ovulation
What is attractivity?
a female’s stimulus value in evoking a sexual response in a male (highest during ovulation)
