Maternally involved galanin neurons in the preoptic area of the rat.

Recent selective stimulation and ablation of galanin neurons in the preoptic area of the hypothalamus established their critical role in control of maternal behaviors. Here, we identified a group of galanin neurons in the anterior commissural nucleus (ACN), and a distinct group in the medial preoptic area (MPA). Galanin neurons in ACN but not the MPA co-expressed oxytocin. We used immunodetection of phosphorylated STAT5 (pSTAT5), involved in prolactin receptor signal transduction, to evaluate the effects of suckling-induced prolactin release and found that 76 % of galanin cells in ACN, but only 12 % in MPA were prolactin responsive. Nerve terminals containing tuberoinfundibular peptide 39 (TIP39), a neuropeptide that mediates effects of suckling on maternal motivation, were abundant around galanin neurons in both preoptic regions. In the ACN and MPA, 89 and 82 % of galanin neurons received close somatic appositions, with an average of 2.9 and 2.6 per cell, respectively. We observed perisomatic innervation of galanin neurons using correlated light and electron microscopy. The connection was excitatory based on the glutamate content of TIP39 terminals demonstrated by post-embedding immunogold electron microscopy. Injection of the anterograde tracer biotinylated dextran amine into the TIP39-expressing posterior intralaminar complex of the thalamus (PIL) demonstrated that preoptic TIP39 fibers originate in the PIL, which is activated by suckling. Thus, galanin neurons in the preoptic area of mother rats are innervated by an excitatory neuronal pathway that conveys suckling-related information. In turn, they can be topographically and neurochemically divided into two distinct cell groups, of which only one is affected by prolactin.

[Fatty acid composition of colostrum and mature human milk in Hungary]. / A colostrum és az érett nói tej zsírsavösszetétele Magyarországon.

INTRODUCTION AND AIMS: Because of the lack of up-to-date data on fatty acid composition of human milk in Hungary, the authors analysed fatty acid composition of colostrum (n = 18, one hind milk sample on day 5 after delivery) and mature milk (n = 15, pooled 24 h collections repeated twice with 2 weeks intervals at median duration of lactation of 4 months) samples with high-resolution capillary gas chromatography. RESULTS: Fat content and fatty acid compositions did not differ in 24 h pooled mature human milk samples obtained with 2 weeks intervals. Significantly lower values of linoleic acid [10.98 (4.81) vs. 14.70 (5.32), % w/w, median (range from the 1st to the 3rd quartile), colostrum vs. mature human milk, p < 0.001] and alpha-linolenic acid [0.22 (0.09) vs. 0.68 (0.21), p < 0.0001], and significantly higher values of arachidonic acid [0.70 (0.56) vs. 0.50 (0.12), p < 0.001] and docosahexaenoic acid [0.22 (0.15) vs. 0.18 (0.06), p < 0.05] were found in colostrum than in mature human milk. Significant and positive correlations were seen between linoleic and arachidonic (r = 0.71, p = 0.001) as well as between alpha-linolenic and docosahexaenoic (r = 0.59, p = 0.01) acid values in colostrum, but not in mature human milk. CONCLUSION: While mature human milk linoleic, arachidonic and alpha-linolenic acid values in this study were in the range usually reported in the literature, the contribution of docosahexaenoic acid to the fatty acid composition of human milk was considerably lower in Hungary than in several other populations.