title: Accelerated maternal responding following intra-VTA pertussis toxin treatment.
abstract: Prior studies have supported a role for mesolimbic dopaminergic mechanisms in the regulation of maternal behavior. Accordingly, the ventral tegmental area (VTA) and its dopaminergic projections to the nucleus accumbens (NAc) and medial prefrontal cortex (mPFC) have been implicated in both the onset and maintenance of normal maternal behavior. To date, studies of direct manipulation of VTA neurochemistry at the onset of maternal behavior have been limited. The current study was undertaken to directly test the hypothesis that enhancement of dopaminergic transmission in the mesolimbic dopamine system can stimulate maternal activity using a pup-induced virgin model. Nulliparous female rats were stereotaxically infused with pertussis toxin (PTX 0, 0.1, or 0.3 μg/hemisphere) into the VTA to chronically stimulate the activity of dopaminergic projection neurons. After 3 days of recovery, maternal responding to donor pups was tested daily, and latency (in days) to full maternal behavior was recorded. Intra-VTA PTX treatment produced a robust dose-dependent decrease in maternal behavior latency, and a long-lasting increase in locomotor activity. These effects were associated with significantly decreased dopamine D1 receptor mRNA expression in the NAc. No effects of PTX treatment on mesolimbic dopamine utilization or mPFC receptor expression were observed. The findings indicate that chronic neural activation in the VTA accelerates the onset of maternal behavior in virgin female rats via modification of the NAc dopamine D1 receptor.
authors.affiliation: Department of Biomedical Sciences Section of Reproduction and Neuroscience, Tufts University, Cummings School of Veterinary Medicine, North Grafton, MA 01536, USA.
authors.forename: John J
authors.initials: JJ
authors.lastname: Byrnes
authors.forename: Erin D
authors.initials: ED
authors.lastname: Gleason
authors.forename: Matthew K
authors.initials: MK
authors.lastname: Schoen
authors.forename: Mathew T
authors.initials: MT
authors.lastname: Schoen
authors.forename: Dennis F
authors.initials: DF
authors.lastname: Lovelock
authors.forename: Lindsay M
authors.initials: LM
authors.lastname: Carini
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Byrnes
authors.forename: Robert S
authors.initials: RS
authors.lastname: Bridges
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D004298:Dopamine / Q000378:metabolism; D005260:Female; D008425:Maternal Behavior / Q000187:drug effects*; D008845:Microinjections; D009043:Motor Activity / Q000187:drug effects; D037342:Pertussis Toxin / Q000008:administration & dosage / Q000494:pharmacology*; D016548:Prosencephalon / Q000378:metabolism / Q000502:physiology; D012313:RNA / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D017447:Receptors, Dopamine D1 / Q000096:biosynthesis / Q000187:drug effects; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013238:Stereotaxic Techniques; D017557:Ventral Tegmental Area / Q000502:physiology*
chemical_list: D017447:Receptors, Dopamine D1; D015102:3,4-Dihydroxyphenylacetic Acid; D012313:RNA; D037342:Pertussis Toxin; D004298:Dopamine