Poster Assignment Recap• Step 1: choose a topic

• Step 2: choose a paper: – must have a hormone measure/manipulation– must have a behaviour measure/manipulation

• Step 3: read the paper very carefully! You should understand everything about this paper, and be able to explain simply

• Step 4: make your poster

• Step 5: practice your talk (5 minutes max!)

Poster Judging• Each of you will judge 3 posters during the times

when they are not presenting• You will get the names of the three posters at

the conference• You will fill in a form to rank the posters you visit• You will also write up and turn in a summary of

each poster (one page per poster) that includes at least three questions you asked at the poster and the replies that you got

• Due date is the last class (Dec 6)

ADX facilitates pairbonding

CORT prevents pairbonding

In males, pair-bonding can’t occur if adrenals removed

In males, stress increases pair-bonding only if adrenals intact

In males, CORT increases pair-bonding

Vasopressin (VP1) receptor

Meadow vole Prairie Vole

Ventral pallidum – important for reinforcement, reward, addiction

Transfection study

• Insert excess V1a gene into the ventral pallidum of prairie voles

VP staining: • reporter gene

(LacZ) only

• V1a

• Additional control was extra V1a in striatum (CP)

Transfection Study

• VP V1a over-expression: • Increase in social behaviour overall• Pair-bonding even without mating • Agrees with antagonist studies

Neurology of Aggression

VMN AH

dorsal PAG

Defensive Aggression

+

+

+

LH-

-

Predation+

-

The two systems are mutually exclusive

Predatory Aggression (Feeding)

Hypothalamus lateral hypothalamus (LH) stimulation elicits predatory attack

Medial amygdala stimulation inhibits predation via LH

Periaqueductal gray (PAG) stimulation also inhibits

predation

Defensive Aggression

• Stimulation of the ventromedial nucleus of the hypothalamus (VMN) produces components of defensive aggression

• Lesions of anterior hypothalamus (AH) prevents VMN effects

• PAG stimulation also elicits defensive aggression

• Medial or basal amygdala stimulation facilitates attacks via VMH

• Central amygdala stimulation inhibits attacks via PAG

Social Aggression

• These forms of aggression can be distinguised from social aggression

• Mostly done in mice and rats• Different neural substrates:

olfactory bulbs (chemosensory cues)basolateral amygdalamedial amygdala (but only if fighting experience)septummedial hypothalamusraphe nuclei (primary 5HT site)

Androgens in Hyena Dominance• Adult females have high levels as well, but

still less than or similar to male

• Androgen levels are strongly correlated with status within sexes

Challenge Effects

• Just like birds and mice

• Seems to require some sort of effort or “ego investment”

• Tennis vs Fan vs Lottery