We previously characterized some crustacean glial cells by markers such as 2',3'-cyclic nucleotide 3'-phosphodiesterase and glial fibrillary acidic protein. Here we use antibodies against glutamine synthetase full-length molecule (anti-GS/FL), a GS C-terminal peptide (anti-GS/20aa-C), and brain S100 (anti-S100), as well as the binding of the insect glia and rat astrocytic marker Datura stramonium lectin (DSL), in the optic lobe of the prawn Macrobrachium rosenbergii. All markers label the lamina ganglionaris cartridge region (lighter: anti-GS/FL; heavier: DSL). In addition, anti-GS/FL labels superficial somata of external and internal medullas and internal chiasm cells. Both anti-GS/20aa-C and anti-S100 label heavily the glial sheaths of the lamina ganglionaris. In addition, anti-S100 binds to the perineurial glia of medullary parenchymal vessels. Western blot analyses show that both anti-GS/FL and anti-GS/20aa-C bind mostly to a band of 50-55 kDa, compatible with a long isoform of vertebrate GS, and accessorily to a possible dimer and, in the case of anti-GS/20aa-C, to an ill-defined band of intermediate mass. Binding of anti-S100 is selective for a single band of about 68 kDa but shows no protein in the weight range of the canonical S100 protein superfamily. DSL reveals two bands of about 75 and about 120 kDa, thus within the range of maximal recognition for rat astrocytes. Our results suggest that phenotype protein markers of the optic lobe glia share antigenic determinants with S100 and (a long form of) GS and that, similarly to vertebrate and insect glia, crustacean glia protein and N-glycan residue markers display regional heterogeneity.

Glial cells, in both vertebrate and invertebrate nervous systems, provide an essential environment for developmental, supportive, and physiological functions. However, information on glial cells themselves and on glial cell markers, with the exception of those of Drosophila and other insects, is not abundant in invertebrate organisms. A common ultrastructural feature of invertebrate nervous systems is that layers of glial cell cytoplasm-rich processes ensheath axons and neuronal and glial somata. In the present study, we have examined the binding of a monoclonal antibody to 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) in the compound eye and optic lobe of the crab Ucides cordatus using both light and electron microscopy. CNPase is a noncompact myelin protein that is a phenotypic marker of oligodendroglial and Schwann cells, is apparently involved in the ensheathment step prior to myelin compaction, and is also expressed by the potentially myelinating olfactory ensheathing glia. CNPase has raised much interest, first by virtue of its unusual enzymatic activity and more recently by its membrane-skeletal features and possible involvement in migration or expansion of membranes. We have found CNPase-like immunoreactivity in most cells of the compound eye basement membrane and both in optic cartridges of the synaptic layer and cells of the outer sublayer of the lamina ganglionaris. The results suggest that in the crab visual system some, but not all, glial cells, including some adaxonal glia, may express the noncompact myelin protein CNPase or a related protein.

ABSTRACT. REPRODUCTlVE ASPECTS 01' PAI.. 4F.MON P4NDAI.lFORMIS (STIMPSON) (DECAPODA, PALAEMONIDAE) AT RATONES MANGROVE, FLORIANÓPOLlS, SANTA CATARINA. Biometric and reproductive aspects ofPalae/JIol1 pandaliformis (Stimpson, 1871) from Ratones Mangrove, Florianópolis, Santa Catarina, havc been investigated. IndividuaIs were monthly collected from August, 91 to July, 93 and the temperature and sa linity registered. Biometry, sex-ratio, sex ual maturity, fecundity and reproductive cycle have been detennined. The tcmperaturc showcd defined temporal distribulion. This species presents alllillal reprodllctivecycle, relatively high individual and populational fecundity, and the ovigerolls females were larger than males and olher females ofthe same species.

Astroglial cells are involved in directional movements of neurons such as migration of the neuronal cell body and growth of neurites. In the mammalian midbrain, medial (M) and lateral (L) radial glia and derived astrocytes differ in their ability to support neuritic growth. In previous work, we have demonstrated that the growthpermissive ability of L astrocytes and non-permissive properties of M astrocytes correlate with the respective composition of the cell surface-associated and secreted glycosaminoglycans (GAGs). Recent work also shows that the GAG-degrading enzyme heparitinase I increases the neurite growth-promoting ability of M midbrain astrocytes (Garcia-Abreu J et al. 2000 Glia 29: 260). In agreement with previous AFM studies of living glial cell lines and cells in primary culture, imaging of living L and M cells at similar load forces showed structures identified as F-actin fibers. Moreover, no systematic differences were observed between L and M pictures. By contrast, the surfaces of formaldehyde-fixed lateral (L) and medial (M) astrocytes differ by the presence of conspicuous 250 nm protrusions in the former, and of a fibrillar network in the extracellular matrix of the latter. Furthermore, we show that treatment with heparitinase I leads to disappearance of the fibrils from M cells and, consequently, to the assumption of an L-like appearance. Our results suggest that the formation of fibrils may follow from an ability to form large aggregates by association of HS carbohydrate units as has been unexpectedly detected by AFM for oligomers of polysialic acid or polysialic acid-containing carbohydrate units of N-CAM, with formation of filament bundles (Toikka J et al. 1998. J Biol Chem 273: 28557). Taken together with the functional effects of heparitinase I treatment, our present results demonstrate an important role of the extracellular matrix on the functional properties of astrocytes. They also emphasize the power and potentialities of AFM in the study of the extracellular matrix on the surface of fixed cells. - ( June 27, 2000 ) . * Supported by PRONEX/ MCT, CNPq, FAPERJ, CEPG/UFRJ. E-mail: gweissmuller@hotmail.com Aggregation of amyloid β peptide (Aβ) into fibrils and deposition as senile plaques are primarily related to neurotoxicity in Alzheimer's Disease (AD). Thus, agents interfering with aggregation may be potentially useful in preventing or decreasing Aβ toxicity. We first studied the effects of guanidine hydrochloride and temperature on the stability of fibrillar Aβ using peptides truncated at different positions. These experiments suggested that hydrophobic interactions mediated by the C-terminal portion of Aβ are important for fibril stability. Based on these results, we found two compounds capable of disaggregating amyloid fibrils at micromolar concentrations, as indicated by light scattering measurements and transmission electron microscopy. When applied to primary cultures of E18 rat hippocampal neurons, both drugs significantly reduced Aβ-induced cell death (as assayed by trypan blue ...