Maternal separation during breastfeeding induces changes in the number of cells immunolabeled to GFAP.

Abstract

The mother-child relationship is fundamental to the establishment and maintenance of synaptic networks and physiological and emotional development. Animal models including maternal separation have been used to study changes at behavioral and neurobiochemical levels. Due to the relevance of glial cells during development, our aim was to determine if short periods of maternal separation during breastfeeding induce permanent changes in a number of astrocytes labeled with the glial fibrillary acidic protein in different brain areas. Wistar rats were housed under standard laboratory conditions with reversed light/dark cycle; food and water ad libitum. Pups were separated from their mothers for 6 h daily during breastfeeding period. On day 22, pups were separately housed according to gender and treatment. At day 60, subjects were evaluated in the elevated plus maze and, after processing for immunohistochemistry, 20-μm sections were made. Prefrontal cortex, paraventricular nucleus, preoptic area, hippocampus and amygdala were localized. Labeled cells were quantified using Image-J program. Results showed that separated females had more entries into open arms and spend more time as compared with the control groups. In the prefrontal cortex we identified a decrease in staining cells in separated females, whereas there was an increase in staining cells in separated males. In the hippocampus and preoptic area, we observed a decrease only in separated males. We did not find any differences in the paraventricular nucleus or amygdala. Our results indicate that maternal separation during breastfeeding induces permanent changes in the number of astrocytes in different brain areas of both males and females.

Early Life Stress Activates Glial Cells in the Hippocampus but Attenuates Cytokine Secretion in Response to an Immune Challenge in Rat Pups

“…There are few reports concerning the immediate effects of ELS on the neuroimmune system [43]. We recently reported that although MS does not decrease the microglial density in the hilus of male pups on PN15, it increases the percentage of activated microglia [8].…”

Cellular count changes in different rat brain areas due to early maternal separation

“…Previous studies have reported that exposure to a protocol of MSDB causes differences in anxiety-like behaviors, which seem to depend on subject's sex and also can be associated with the alteration of expression by GABA A receptors. Other authors support evidence regarding the number of astrocytes in certain brain areas of separated rats compared with those that were not separated [18,20,21].…”

“…In fact, alterations of the axis that regulates the response to stress have been reported using MSDB model in rats [8]. Our research group has contributed studies regarding behavioral changes of the separated subjects and differences associated with subject's sex [18,20].…”

“…The results at the hippocampal area, indicate a higher cell count for marked and non-marked GFAP cells in male subjects, on the other hand, female subjects showed less cell count for marked and non-marked cells; this discrepancy between sex groups has been largely found in previous studies from our research group and other groups. Previous articles from our research group have explained other details addressing the changes in the hippocampus cell count [18,20].…”

“…The procedure was performed as previously reported [20]. The 20μm slices were incubated with blocking serum [bovine serum albumin, 0.3% Triton X-100, normal goat serum] for 1 h. Then, incubated with primary antibody anti-GFAP (Sigma-Aldrich Cat# G4546, RRID:AB_1840895) for 12h at room temperature before undergo incubation with biotinylated anti-rabbit secondary antibody (Vector Laboratories Cat# PK-6100, RRID:AB_2336819) at a dilution of 1:500 in 0.3 % PBS Triton for 90 min, and then with antibody (AB) complex for 90 min.…”