M Sparapani

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We have studied in a well-characterized in vitro neuronal system, cultures of cerebellar granule cells, the toxicity of polyamines endogenously present in the brain: spermine, spermidine, and putrescine. Twenty-four-hour exposure of mature (8 days in vitro) cultures to 1-500 microM spermine resulted in a dose-dependent death of granule cells, with the(More)
Young adult rats were chronically treated with lithium (2.5 mmol/kg/day) for 16 days. The day after the last lithium administration, rats were injected s.c. with the excitotoxic convulsant kainic acid (10 mg/kg). As compared to saline controls, lithium-treated rats had no apparent attenuation of convulsions. Furthermore, the induction of brain ornithine(More)
Pharmacological blockade of the (NMDA) receptor at critical stages of brain development may have long-lasting effects on brain chemistry and on animal behavior. We report here experiments in which the competitive NMDA receptor antagonist CGP 39551 was administered to rat pups from postnatal day 7 (P7) to P18. The stage of treatment was selected to primarily(More)
A competitive antagonist of the N-methyl-D-aspartate receptor, CGP 39551, was administered daily to neonatal rats with increasing doses from postnatal day 1 to 22. These animals displayed approximately 50% decrease of body weight at the end of treatment and, therefore, both normal and neonatally undernourished rats were used as controls. At a young adult(More)
Pregnant rats were treated for five consecutive days during gestation with s.c. injections of the ornithine decarboxylase (ODC) inhibitor alpha-difluoromethylornithine (DFMO). Treatment beginning at gestational days 13 or 14 was effective in inhibiting ODC and altering polyamine levels, and resulted in relatively small decreases in body and forebrain(More)
Microglial cells, like macrophages, are very sensitive to ricin, a galactose-specific toxic lectin belonging to the family of ribosome-inactivating proteins. This toxin can be taken up by most cells through the binding of its B chain to galactose-containing molecules on the cell membrane. In macrophagic cell types it can be internalised also by mannose(More)
Ornithine decarboxylase (ODC), the key enzyme for polyamine biosynthesis, dramatically decreases in activity during normal cerebellar development, in parallel with the progressive differentiation of granule neurons. We have studied whether a similar pattern is displayed by cerebellar granule neurons during survival and differentiation in culture. We report(More)
Involvement of proteases has been postulated in several neurodegenerative processes. Accordingly, protease inhibition has been proposed as a potential therapeutic tool to limit damage in some neuropathological states. The timed turn-over of proteins is, however, an essential biochemical process and its prolonged block may be dangerous to the cell. We report(More)
Microencephalic rats obtained by gestational treatment with the DNA alkylating agent methylazoxymethanol, show a remarkable lack of sensitivity to excitotoxic neuropathology caused by systemic injections of the convulsant neurotoxin kainic acid. Taking advantage of this, we have studied in these rats, as well as in normal rats, the relationship between the(More)
Polyamines and the key enzyme for their biosynthesis, ornithine decarboxylase (ODC) play an important role in the control of neuronal proliferation and differentiation. Exposure to agents that interfere with normal cell maturation is expected to result in alteration of neuronal ODC developmental pattern. We have administered to newborn rats, about 6 and 30(More)