Effects of tacrine upon murine neuroblastoma cells

The cell cycle hypothesis of Alzheimer's disease: Suggestions for drug development

The cell cycle of hypothesis of neural dysfunction in chronic neurodegenerative conditions such as Alzheimer's disease (AD) offers a unified approach to understanding both existing and novel strategies for drug development. At the present time, a ligand based approach is a pragmatic solution for identifying new chemical leads on which to base future discovery and optimisation. We have pursued a ligand based approach on the basis of public domain data to identify existing compounds capable of abrogating the cell cycle at the G0-G1 interface. Selected on this basis, irrespective of the tissue under study, we identified several classes of compounds as potential chemical leads. Of these compounds, at least ten have already been shown to be neuroprotective in animal models of acute neurodegeneration. Such compounds could form the basis of a screening exercise after development of suitable screening tools. Progressing of chemical leads through such an approach will be more efficient if future leads display relevant "drug-like" properties. Further, drug development in this arena should take account of the special concerns raised by targeting an elderly population. This will involve accounting for frequent polypharmacy in the aging population, and age-related alterations in physiology.

Lectin cytochemistry of rat cerebral and cerebellar neuronal cells

Lectin cytochemistry of normal rat central nervous system (CNS) was performed on formalin-fixed, paraffin-embedded sections by using 14 lectins and light and electron microscopy. Hippocampal neurons reacted positively with Griffonia (Bandeiraea) simplicifolia lectin I (GSL-I), Griffonia (Bandeiraea) simplicifolia lectin II (GSL-II) and Vicia villosa agglutinin (VVA); neurons in the cornu ammonis (CA) 2 region reacted positively with GSL-I and GSL-II, and neurons in the CA2 and CA3 regions reacted with VVA. Cortical neurons reacted positively with GSL-I and VVA. Cerebellar Purkinje cells and granule cells were reactive with Phaseolus vulgaris leukoagglutinin (PHA-L). Cerebellar nucleus neurons were also reactive with PHA-L and VVA. Reactivity with GSL-I, GSL-II, VVA and PHA-L was observed only on the neuronal cell surface. The present findings demonstrate the differences between cerebral and cerebellar neurons in reacting with glycoconjugates.

Identification of lectin binding sites in the rat brain

Lectins belong to a class of proteins or glycoproteins able to bind carbohydrates. The study reported here describes the identification of lectin-binding sites in the adult rat brain. The results indicate that among the 31 lectins utilized, eight show a specific positive reaction with neurons. Staining was also observed with other cerebral structures such as myelin, leptomeninges, choroid plexus and capillaries. Lectins are, therefore, an important histochemical tool and can be easily and reliably used for the identification of cells and cerebral structures in the adult rat brain.