GABA receptor agonists in the medial preoptic area and maternal behavior in lactating rats.
We studied the effects of injecting agonists of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) muscimol (GABA-A receptor agonist) and baclofen (GABA-B receptor agonist) in the medial preoptic area (MPOA) and neighboring brain regions, the bed nucleus of the stria terminalis (BNST), and lateral preoptic area (LPO) on maternal behavior. Lactating female rats were implanted with bilateral cannulae in the MPOA/BNST on day 1 postpartum. On day 5, a maternal behavior test was conducted in the home cage after females received injections of muscimol or baclofen (0, 12.5, 50 or 200 ng per side). On day 7, after MPOA/BNST injections, a second maternal behavior test was conducted with pups placed at the end of a T-runway projecting from the home cage. Finally, after injections on day 9 maternal aggression, olfaction, and locomotor behavior were tested. The GABA receptor agonists injected in the MPOA/BNST produced dose-dependent deficits in all components of maternal behavior, including maternal aggression, except licking. Muscimol produced deficits in the active component, nest building at lower doses than baclofen, both agonists produced deficits in retrieving, while baclofen produced deficits in passive components (hovering and crouching over pups) at lower doses than muscimol. Both GABA receptor agonists increased locomotor activity and reduced olfactory responsiveness but these were only correlated with deficits in retrieving and crouching in baclofen-treated females.
Arrati
Porfirio Gómora
PG
Centro de Investigación en Reproducción Animal, CINVESTAV-UAT, Apdo Postal 62, Tlax. Tlaxcala 90000, Mexico.
Carmona
Cesar
C
Dominguez
Guadalupe
G
Beyer
Carlos
C
Rosenblatt
Jay S
JS
D000704:Analysis of Variance; D000818:Animals; D001418:Baclofen / Q000008:administration & dosage; D016009:Chi-Square Distribution; D005260:Female; D018755:GABA Agonists / Q000008:administration & dosage*; D007774:Lactation / Q000502:physiology*; D008425:Maternal Behavior / Q000187:drug effects / Q000502:physiology*; D008845:Microinjections; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D009118:Muscimol / Q000008:administration & dosage; D011301:Preoptic Area / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D018079:Receptors, GABA / Q000187:drug effects / Q000502:physiology*; D012686:Septal Nuclei / Q000187:drug effects* / Q000502:physiology; D018709:Statistics, Nonparametric
D018755:GABA Agonists; D018079:Receptors, GABA; D009118:Muscimol; D001418:Baclofen