Behavioral components of milk-induced activation in neonatal rat pups

Neonatal rat pups exhibit a complex constellation of behaviors in response to a variety of salient stimuli such as the odor of milk or maternal saliva, stroking with a soft brush, electrical brain stimulation, and intraoral infusions of milk. Although psychobiologists have used the term "behavioral activation" to refer to such behavioral displays, the exact nature of "behavioral activation" and its underlying neural substrates have yet to be elucidated. This study was undertaken to characterize "behavioral activation" quantitatively to describe and define this apparently global pattern of response in terms of possible underlying components. Principal components analysis suggested that "behavioral activation" may be comprised of separable ingestive, exploratory, and locomotor behavioral "assemblies."