Zinc and glutamine improve brain development in suckling mice subjected to early postnatal malnutrition.

OBJECTIVE: The effect of zinc and glutamine on brain development was investigated during the lactation period in Swiss mice. METHODS: Malnutrition was induced by clustering the litter size from 6-7 pups/dam (nourished control) to 12-14 pups/dam (undernourished control) following birth. Undernourished groups received daily supplementation with glutamine by subcutaneous injections starting at day 2 and continuing until day 14. Glutamine (100 mM, 40-80 microL) was used for morphological and behavioral studies. Zinc acetate was added in the drinking water (500 mg/L) to the lactating dams. Synaptophysin and myelin basic protein brain expressions were evaluated by immunoblot. Zinc serum and brain levels and hippocampal neurotransmitters were also evaluated. RESULTS: Zinc with or without glutamine improved weight gain as compared to untreated, undernourished controls. In addition, zinc supplementation improved cliff avoidance and head position during swim behaviors especially on days 9 and 10. Using design-based stereological methods, we found a significant increase in the volume of CA1 neuronal cells in undernourished control mice, which was not seen in mice receiving zinc or glutamine alone or in combination. Undernourished mice given glutamine showed increased CA1 layer volume as compared with the other groups, consistent with the trend toward increased number of neurons. Brain zinc levels were increased in the nourished and undernourished-glutamine treated mice as compared to the undernourished controls on day 7. Undernourished glutamine-treated mice showed increased hippocampal gamma-aminobutyric acid and synaptophysin levels on day 14. CONCLUSION: We conclude that glutamine or zinc protects against malnutrition-induced brain developmental impairments.

The developing left superior cervical ganglion of Pacas (Agouti paca).

In this study the main question investigated was the number and size of both binucleate and mononucleate superior cervical ganglion (SCG) neurons and, whether post-natal development would affect these parameters. Twenty left SCGs from 20 male pacas were used. Four different ages were investigated, that is newborn (4 days), young (45 days), adult (2 years), and aged animals (7 years). By using design-based stereological methods, that is the Cavalieri principle and a physical disector combined with serial sectioning, the total volume of ganglion and total number of mononucleate and binucleate neurons were estimated. Furthermore, the mean perikaryal (somal) volume of mononucleate and binucleate neurons was estimated using the vertical nucleator. The main findings of this study were a 154% increase in the SCG volume, a 95% increase in the total number of mononucleate SCG neurons and a 50% increase in the total volume of SCG neurons. In conclusion, apart from neuron number, different adaptive mechanisms may coexist in the autonomic nervous system to guarantee a functional homeostasis during ageing, which is not always associated with neuron losses.

Macro- and microstructural organization of the rabbit's celiac-mesenteric ganglion complex (Oryctolagus cuniculus).

The macro- and microstructures of the rabbit celiac-mesenteric ganglion complex are described in 20 young animals. We found ten celiac ganglia, twenty-seven cranial mesenteric ganglia and eleven celiac-mesenteric ganglia. The celiac ganglia had a rectangular shape in nine cases (90%) and a circular one in one case (10%). The cranial mesenteric ganglia presented triangular (66.7%), rectangular (11.1%), L-shape (18.5%) and semi-lunar (3.7%) arrangements. The celiac-mesenteric ganglia were organized in three patterns: a single left celiac-mesenteric ganglion having a caudal portion (72.7%); celiac-mesenteric ganglia without a caudal portion (18.2%) and a single celiac-mesenteric ganglion with two portions: left and right (9.1%). The microstructure was investigated in nine celiac-mesenteric ganglia. The results showed that the celiac-mesenteric ganglion is actually a ganglion complex constituted of an agglomerate of ganglionic units separated by nerve fibers, capillaries and septa of connective tissue. Using the semi-thin section method we described the cellular organization of the celiac-mesenteric ganglion complex. Inside of each ganglionic unit, there were various cell types: principal ganglion neurons (PGN), glial cells (satellite cells) and SIF cells (small intensely fluorescent cells or small granular cells), which are the cytologic basis for each ganglionic unit of the rabbit's celiac-mesenteric ganglion complex.