Further evidence for the dissociation of locomotor activity and head dipping in rats.

Three studies were conducted to determine if ambulation and head-dipping behavior were differentially responsive to environmental or pharmacological variables. The first study showed that the presence of another animal in an adjacent box reduced head-dipping behavior but had no significant effect on ambulation. The second study showed that this effect was due to visual stimulation from the adjacent box. The third study showed that scopolamine affected head dipping but not ambulation. The conclusion is that ambulation and head dipping are different behaviors rather than different manifestations of the same behavior--exploration--and are, therefore, under the influence of different brain functions.