Medial preoptic area interactions with the nucleus accumbens-ventral pallidum circuit and maternal behavior in rats.
Several experiments explored the roles of nucleus accumbens (NA), ventral pallidum (VP) and medial preoptic area (MPOA) in the regulation of maternal behavior in rats. A preliminary experiment found that bilateral radiofrequency lesions of medial NA did not disrupt maternal behavior. Experiment 1 found that bilateral infusions of muscimol into VP, but not into medial NA, reversibly disrupted maternal behavior. Experiment 2 found that unilateral muscimol injections into VP disrupted maternal behavior to a greater extent when paired with a contralateral N-methyl-d-aspartic acid (NMDA) MPOA lesion than when paired with a sham MPOA lesion. Experiment 3 showed that a unilateral NMDA MPOA lesion paired with a contralateral NMDA VP lesion (Contra group) disrupted maternal behavior to a much greater extent than did sham NMLA lesions or NMDA lesions of MPOA and VP ipsilateral to one another. Experiment 3 focused on the specificity of the maternal behavior disruptions and found that the primary maternal deficit in the Contra females was a severe deficit in retrieval behavior. Importantly, these females showed normal hoarding behavior, home cage activity, and elevated plus maze activity. Experiment 3 used Neu N immunohistochemistry to define the extent of MPOA and VP excitotoxic lesions. It is hypothesized that MPOA acts to facilitate the active components of maternal behavior by inhibiting NA, which then releases VP from GABAergic inhibition, and such disinhibition of VP allows pup stimuli to trigger appropriate maternal responses.
Numan
Michael
M
Department of Psychology, Boston College, McGuinn Hall, 140 Commonwealth Avenue, Chestnut Hill, MA 02467, USA. numan@bc.edu
Numan
Marilyn J
MJ
Schwarz
Jaclyn M
JM
Neuner
Christina M
CM
Flood
Thomas F
TF
Smith
Carl D
CD
D000704:Analysis of Variance; D000818:Animals; D004305:Dose-Response Relationship, Drug; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D005260:Female; D007839:Functional Laterality; D018755:GABA Agonists / Q000494:pharmacology; D005917:Globus Pallidus / Q000187:drug effects / Q000502:physiology*; D007150:Immunohistochemistry / Q000379:methods; D008425:Maternal Behavior / Q000187:drug effects / Q000502:physiology*; D009043:Motor Activity / Q000187:drug effects; D009118:Muscimol / Q000494:pharmacology; D016202:N-Methylaspartate / Q000494:pharmacology; D009415:Nerve Net / Q000502:physiology*; D016571:Neural Networks, Computer; D009714:Nucleus Accumbens / Q000502:physiology*; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D049590:Postpartum Period / Q000187:drug effects / Q000502:physiology; D011301:Preoptic Area / Q000187:drug effects / Q000293:injuries / Q000502:physiology*; D051381:Rats; D011930:Reaction Time / Q000187:drug effects; D013194:Staining and Labeling / Q000379:methods; D013997:Time Factors
D018690:Excitatory Amino Acid Agonists; D018755:GABA Agonists; D009118:Muscimol; D016202:N-Methylaspartate; D010751:Phosphopyruvate Hydratase