da 3

Question 1

whats the problem with using electroencephalography to measure the NAc

Answer 1

its a scalp measure- nac too deep

Question 2

fMRI as a NAc measure

Answer 2

nac is too small- fmri has limited spatial resolution

need rats to be anaesthetised for fMRI - need to be awake for reward

Question 3

electrophysiology?

Answer 3

allows us to record from populations of brain cells but connectivity of NAc makes things difficult.
hippocampal and dopaminergic vta inputs make connections with the same NAc neuron

Question 4

What is the best method

Answer 4

Microdialysis- only VTA neurons use dopamine.

Question 5

microdialysis

Answer 5

enables sampling and collecting of small molecular weight substances from the interstitial space.
one of the techniques which permits direct quantification of neurotransmitters in behaving animals 0 requires the chronic implantation of dialysis probe

• Da on the outside of the membrane diffuses through along concentration gradient - into the outflow tubing

Question 6

Hernandez and Hoebell (1988)

Answer 6

local injections of cocaine increased da in the NAc and decreased DOPAC

Question 7

Ranaldi et al., (1999)

Answer 7

injections of amphetamine- trained rats to press lever to self administer.
Da levels measured .
initial loading phase- hit lever lots
the naintenance
extinction causes reloading phase.
indicating that self administration of amphetamine is under the influence of DA levels at the nac

Question 8

Xi et al., (1998)

Answer 8

heroin self administartion. Dose dependent increases of DA in the Nac- and frequency of self administartion declines as a function of dose.

• heroin coadministered wth Nalocxone (opiod antagonist) reduce amount of DA in Nac.

Question 9

Lecca et al., (2007)

Answer 9

s/a vs yoked. S/a showed higher da levels. 
after 4 weeks showed similar levels. BUT
Reversal of shell/ core dichotomy. 
SA= shell (hedonic)  
Yoked= core (pre-motor)

Question 10

hernandez and hoebell (1988) - natural rewards

Answer 10

Da in the nac increased when presented with food. remains high - learning
stimulation of the lateral hypothalamus caused increased da in nac and food.seeking behaviour.

• Sex:
  sexually experienced rats increased da in the nac after exposure to female rats bedding.