Functional importance of nucleus accumbens noradrenaline in the rat.

l-Noradrenaline. HCI (l-NA), d-noradrenaline.HCI(d-NA) and dopamine.HCI (DA)were locally applied in the nucleus accumbens of awake rats. When the animals were observed in a dark open field arena it was found that low doses of l-NA or DA produced suppression of ambulatory activity followed by an increase in the activity at higher doses. l-NA was more potent than DA in producing these effects and about 4 times higher doses of DA were required to produce the same effect. d-NA was not without effects but was less efficient than DA.