Exam 3 Flashcards
Affiliative Social Behaviors
- Social behaviors that bring animals together
- Ex: Reproductive, Parental, Bonding
Aggressive Social Behaviors
- Social behaviors that keep animals apart
- Ex: threat/attack, territorial (aggression in defense of physical area)
What is Pair-bonding?
- An enduring, preferential association between two sexually mature adults
–> characterized by selective contact, affiliation, & copulation w/ the partner (vs. a conspecific)
-often involves biparental care of the young - Adaptive to help the species survive
Benefits of Pair Bonding in Humans
- Live longer (vs. unpaired counterparts)
- increased intimacy
–> inversely correlated with negative psych states (i.e. depressed mood)
–>positively correlated with immune function, cardiovascular health, and kids’ psych/physical wellbeing
Prairie Vole Model of Pair Bonding
- Socially monogamous rodents that live primarily in the US grasslands (limited food/water may have played a role in the development of their pair bonding)
- Early Field Studies: using multiple-capture traps, they noticed same pairs repeatedly captured together
- Pair remains together until one dies and the surviving partner usually does NOT pair w/ new mate
This social behavior functions to keep individuals together
Affiliative behavior
This hormone has been linked to aggressive behavior
testosterone (androgens)
Aggression and affiliation brain regions largely overlap, except for this brain region which is involved in aggression
periaqueductal gray (PAG)
Oxytocin into this brain region induces pair bonding in prairie vole
nucleus accumbens (or prefrontal cortex)
Males are more sensitive to the ability of this hormone to induce pair bonding
Arginine vasopressin (AVP)
This social behavior functions to keep individuals apart
aggressive behavior
This type of vole does not display pair bonding behavior
meadow vole
Pair bonding is induced by this behavior
mating behavior
Injecting AVP into the brain region induces pair bonding
lateral septum (LS)
This ‘idea’ suggests that testosterone and aggression are tightly linked only during certain times of the lifespan or in certain contexts
Challenge Hypothesis
This refers to the property of a system that regulates its internal environment to maintain stable conditions
homeostasis
This type or thirst is regulated by angiotensin
volemic thirst (or hypovolemia)
This is the key brain region of the feeding circuit
arcuate nucleus (ARC) of the hypothalamus
This hormone is a long-term regulator of food intake that comes from adipose tissue
leptin
These two hormones are made in the brain and have opposite effects on feeding
neuropeptide Y (NPY) and melanocycte stimulating hormone (MSH)
This type of period refers to activities that occur less than 24 hours apart
ultradian
This hormone displays a circadian rhythm that is tied to light exposure and not peak activity of animals
melatonin
This brain region is the most critical ‘coordinating’ clock
suprachiasmatic nucleus (SCN)
This is the connection directly between the eye and the SCN
retinohypothalamic tract
This will happen to the activity of a free-running hamster when pulsed with light late in the ‘subjective night’?
“advance sunrise”/advance activity
Animals that are most active at dawn and dusk have this type of cycle
crepuscular
The key circadian hormone melatonin is made in this endocrine tissue
pineal gland
This refers to any type of environmental cue that synchronizes internal clock or biological rhythm
zeitgeber
In the absence of any light, mammals will show this type of circadian rhythm
“free running”
This type of clock is determined by signals outside the organism
exogenous
What do female meadow voles do in the winter?
They let their territories that are normally separate overlap to form same-sex groups
- helps with the limited resources and promotes survival
What aspects of biparental care do male prairie voles exhibit?
- Direct: huddling, grooming, contact, retrieving pups
- Indirect: nest building, food hoarding
- Paternal behavior towards offspring persists after the birth of subsequent litters
- Offspring show attachment to the parents through increased vocalization if separated
Which hormones are involved in social behavior? (BIG 2)
- Oxytocin (OT) is associated with increased maternal care
- Vasopressin (AVP) is associated with increased aggression
**Act in a paracrine manner on neighboring cells
Vasopressin Receptor Results in Prairie Voles
Higher AVP receptors in:
- Bed nucleus of the stria terminalis (BNST) -> relays neural info relevant to homeostasis
- Ventral Pallidum (VP) -> reward
- Amygdala -> emotion
- Accessor olfactory bulb -> inputs from the vomeronasal organ
Lower AVP receptors in:
- Medial prefronal cortex (mPFC) -> attention, executive function
- Lateral Septum (LS) -> emotion, stress
–>Cohabitation in PV increases # of AVP neurons in BNST that project to LS
–> AVP injection facilitates pair bonding in males
–>V1a receptor in monogamous voles not seen in promiscuous
Oxytocin Receptor Results in Prairie Voles
Higher OT receptors in PV:
- Bed nucleus of stria terminalis
- Medial prefrontal cortex (mPFC)
- Nucleus Accumbens (NAcc) -> motivation and reward
Lower OT receptors in PV:
- Hypothalamus
- Lateral septum
- Amygdala
–> Injecting OT into the NAcc or mPFC induces pair bonding even w/o mating
Men with more RS3 repeats
- inc. entrepreneurship
- dec. score on Pair Bonding Scale
- dec. likely to be married
- inc. marital crisis/threat
Intranasal OT effects on gambling
- OT increases willingness to accept risk when associated with social interaction
–> no effect if investor gives money to a “project” instead of a trustee
Which sex of PV is more sensitive to OT?
Female
Aggression
- Overt behavior with intention to harm another individual
- Elicited by different stimuli (may be adaptive or maladaptive and varies over the course of lifetime)
- Many hormones modulate these behaviors such as androgens, estrogen, and serotonin (and their receptors)
Agnostic Behavior
- Aggressive and submissive behaviors elicited in social context
Two ways of looking at them:
- Single continuum (single scale of submissive to aggressive)
- Separate continuum (aggression and submission are on two separate scales of high to low)
Set point
a value that homeostatic systems will work to achieve that is optimal for the functioning of the organism
Osmotic Thirst
Body has too much salt -> add water
Hypovolemia
Body is losing balanced fluids (blood, vomit, diarrhea, sweat) -> add Gatorade
What hormone regulates water balance?
Vasopressin = Antidiuretic hormone (ADH)
- works in renal tubes to retain water
–> a lack of AVP/ADH causes diabetes insipidus (an overdrinking of water and excessive urination)
What hormone stimulates drinking during hypovolemia?
Angiotensin II
–> acts with aldosterone with from zona glomerulosa of adrenal glands
Why is it hard to study neural/endocrine mechanisms or even a single hormone/neuropeptide?
Another system kicks in to reverse the effects of the manipulation
Postprandial
right after eating
Postabsorptive
digestive tract empty, energy stored
Where is insulin produced?
Beta cells in the pancreas
Effects of Insulin
- increase glucose absorption and storage as glycogen or fat
- decrease blood glucose
- decrease glucose secretion
Effects of Glucagon
- causes liver to convert glycogen to glucose
- increase blood glucose levels
- pancreas releases glucagon when -> blood sugar is low and higher insulin levels
During stress or severe energy expenditure, what do glucocorticoids do?
mobilize glucose from liver/muscle
Streptozotocin
drug that selectively destroys beta cells, induces diabetes
Where are there insulin receptors in the brain?
arcuate nucleus (ARC) of the hypothalamus
Neuropeptide Y (NPY)
- Anabolic/Orexigenic effectors: increase appetite and food intake; suppress energy metabolism
- stimulated by ghrelin
- inhibited by leptin and insulin
Melanocyte Stimulating Hormone
- Catabolic/Anorexigenic effectors: decrease appetite and food intake, suppress energy metabolism
- stimulated by leptin (also insulin, amylin, CCK)
Long-term regulator of food intake
Leptin (inhibitory)
Short-term regulators of food intake
Insulin (inhibits)
Amylin (inhibits)
Ghrelin (stimulates) –> mad by epsilon cells of pancreas
What hormone peaks just before each meal?
Ghrelin
What does ghrelin stimulate?
NPY neurons of the ARC and feeding
What tissue produces leptin?
Adipose (leptin levels are proportional to body fat)
Amylin
Peptide hormone secreted from pancreas
- decreases glucose absorption
- decreases glucagon secretion
- promote satiety
- slows gastric emptying and reduces food intake
Chronobiology
field that examines biological rhythms in living organisms and their adaptation to solar (and lunar) related rhythms
Period
repeating cycle of phenomena over time
Ultradian
< 24 hours
Sleep cycles, feeding
Circadian
~24 hours
sleep/wake
Infradian
> 24 hour
Circalunar
~28 days
menstrual
Circannual
~ 1 year
mating
Diurnal
active during the day
- ex: humans, horses, squirrels
Nocturnal
active at night
- ex: hamsters, raccoons, owls
Crepuscular
active at dawn and dusk
- ex: deer, rabbits, mosquitos
Matutinal
dawn only
Vespertine
dusk only
Zeitgeber
potent environmental cue that synchronizes internal clock or biological rhythm
–> light is the primary zeitgeber among many animals
Lesioning of the SCN
eliminates circadian organization of physiology and behavior
