Lecture 14- Aggression

Aggression

Directed behavior at a peer or predator that is generally evoked as a defense mechanism

What did Darwin have an interest in?

Situations which elicited aggressive vs. submissive behaviors in dog breeds

What types of social behaviors buffer the effects of stress?

Love and allogrooming

What results in being the target of aggression?

Reduction of preference for interacting with a social peer

Cutting the brain so that the cortex is isolated from the hypothalamus resulted in what? (cats)

Persistent hissing and scratching in cats

Lesions of the lateral septum (LS) evoked what?

Aggressive behavior, "septal rage"

In the brain, electrical lesions destroy what?

Cell bodies and axons

Muscimol

GABA agonist that when injected into a brain area silences the region for 2-3 hours

What happens if muscimol is infused into the lateral septum?

Produces aggressive behavior in male and female mice

What does optogenetic activation of the lateral septum do?

Suppresses attacks directed at an intruder mouse

What is the role of the lateral septum?

Acts to suppress rage

What other area other than the lateral septum acts to suppress aggression?

The ventromedial hypothalamus

What happens if a submissive mouse is introduced?

Causes an increase in VMHvl activity

What does suppressing the VMHvl do?

Reduces aggression seeking responses

What does activating the VMHvl do?

Aggression-seeking

What VMHvl neuron controls aggression in males and females?

Estrogen receptor 1

In response to aggression in rats what happens in the nucleus accumbens?

Dopamine surges

What might be important as a consequence of aggression?

To remember, learn, and be rewarded by aggression

CD1 strain

Variation in whether mice have aggressive behavior, only 2/3 have aggression

Place preference

Mice given a choice between being aggressive or not, they prefer being aggressive

How do mice work to self-administer aggression?

After the moues has learned how much he wants to be aggressive, he will repeatedly lever press to earn the opportunity

How does "craving" aggression work in mice?

As time goes on, the motivation for aggression increases the more you dont have it.

What is the idea of social reward from affiliative behavior in rats?

Rats will work to just hang out with a familiar rat in the same setup

What is the connection between alcohol and aggression?

A low dose of alcohol causes aggression when there would be none