Interaction with pups enhances dopamine release in the ventral striatum of maternal rats: a microdialysis study.

A growing body of evidence suggests that an interference with dopamine (DA) transmission disrupts maternal behavior in the rat. The present brain microdialysis study was therefore conducted to investigate whether infants can modulate ventral striatal DA release in mother rats. There was a significant rise in the extracellular concentrations DA, 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) in the ventral striatum when mothers were reunited with their litters following separation overnight. Nursing was the predominant behavior during this phase of the experiment. More active behaviors were elicited by soiling pups with flowerpot earth, and this was accompanied by further increases in DA, DOPAC, HVA, and 5-HIAA. It is suggested that pup-induced stimulation of ventral striatal DA release facilitates parental responses such as pup retrieval.