Differential expression of heat shock 70 proteins in primary cultures from rat cerebellum.

While a number of studies have described the heat shock response in established cell lines and in primary cultures of cells derived from the nervous system, there has been no systematic analysis comparing expression and localization of the inducible heat shock 70 (hsp70) proteins and the constitutively synthesized members of the family (hsc70) in neurons and glia. In the present communication, we utilized specific probes to compare the expression of hsp70 and hsc70 mRNAs and proteins in two types of primary cultures, astroglial and neuro-astroglial, from postnatal rat cerebellum. Conditions were adjusted to maintain physiological numbers of microglia in both types of culture, and cultures were analyzed at a number of different time points following a precisely defined heat shock.

Postnatal decrease of acetate concentration in rat cerebellum.

We examined the evolution of 1H-NMR detectable metabolites in rat cerebellum from the postnatal day 1-25, a period associated with intense metabolic changes as well as physiological and morphological modifications. The unexpected result reported here is the existence of a high concentration of acetate in neonatal rat cerebellum, progressively decreasing with age and maturation. In contrast, the cerebellum content of various metabolites such as N-acetyl-L-aspartate (NAA), glutamate, and aspartate increases from the first day onward.

[1-13C]glucose metabolism in rat cerebellar granule cells and astrocytes in primary culture. Evaluation of flux parameters by 13C- and 1H-NMR spectroscopy.

The metabolism of [1-13C]glucose in rat cerebellum astrocytes and granule cells was investigated using 13C- and 1H-NMR spectroscopy. Near homogeneous primary cultures of each cell type were incubated with [1-13C]glucose, under the same conditions. Analysing the relative 13C enrichments of metabolites in spectra of cell perchloric acid extracts, on the one hand, the 13C-1H spin-coupling patterns in 1H-NMR spectra of cell medium lactate and the 13C-13C spin-coupling patterns in 13C-NMR spectra of purified cell glutamate, on the other hand, showed significant differences, between the two cell types, in the activity of various metabolic ways.

N-acetyl-L-aspartate and acetate 1H NMR signal overlapping under mild acidic pH conditions.

The pH dependence of methyl proton chemical shifts of acetate, acetoacetate, N-acetyl-L-aspartate (NAA), and N-acetyl-L-aspartyl-L-glutamate (NAAG) were studied from pH 3 to pH 9. Only slight shifts of acetoacetate, NAA, and NAAG methyl signals were observed, whereas the acetate signal was largely shifted as a result of the titration of its acidic function. At pH 4.

Plasticity of astroglial glutamate and gamma-aminobutyric acid uptake in cell cultures derived from postnatal mouse cerebellum.

The plasticity of astroglial glutamate and gamma-aminobutyric acid (GABA) uptakes was investigated using mouse cerebellar cell cultures. The influence of external factors, such as different sera and/or the presence of neurons, was examined. Control autoradiography experiments showed that after short-term exposure to radioactive amino acids, granule cells took up neither glutamate nor GABA, and beta-alanine predominantly inhibited astroglial GABA uptake.