Intracellular preoptic and striatal monoamines in pregnant and lactating XXXX : possible role in maternal behavior.

@entity1 @entity4925 @entity146 @entity935 @entity750 @entity35
In many mammals, hormonal fluctuations during pregnancy and parturition produce neurochemical events that are necessary for the transition from a non-maternal state to a maternal state that occurs when @entity1 are born. However, the nature of these events is mostly unknown. We investigated whether changes in @entity935 (DA) and @entity750 ( @entity750 ) activity within the preoptic area (POA) and striatum, neural sites important for some @entity146 , could be part of this process. Female @entity35 were sacrificed as either diestrus virgins, on pregnancy day 10 or 20, on the day of parturition, or on day 7 or 17 of lactation. Bilateral tissue punches from the POA, dorsolateral striatum (ST(dl)), and nucleus accumbens (NA) were obtained and levels of intracellular DA and @entity750 analyzed with high-performance liquid chromatography with electrochemical detection (HPLC-EC). In the POA, DA was high in virgins and during early pregnancy, lowest on the day of parturition, and very high during lactation. Although there were no changes in the @entity4925 to DA ratio (i.e., turnover), @entity4925 levels also followed this pattern. @entity750 turnover in the POA was lower in virgins compared to other groups. In the ST(dl), DA turnover was highest during late pregnancy and on the day of parturition, while no changes in @entity750 measures were found. No significant effects were found in the NA. Therefore, decreased DAergic activity in the POA and increased DAergic activity in the ST(dl) occurs around parturition, the time when maternal behavior emerges, and may influence its onset.
