TRANSGENIC ANIMALS AS MODELS IN THE STUDY OF THE NEUROBIOLOGICAL ROLEOF POLYAMINES

Natural polyamines, putrescine, spermidine and spermine, exhibit a num ber of neurophysiological and metabolic effects in brain preparations. In the in vitro studies, several specific sites of action have been i dentified such as ion channels, transmitter release and Ca2+ homeostas is. Polyamines have been linked to the development of neuronal degener ation caused by, for instance, epileptic seizures and stroke. The role of endogenous polyamines in the functioning brain is not clear, howev er. We review the work carried out using state-of-the-art transgenic a nimal models for polyamine research. A number of transgenic mouse line s carrying human ornithine decarboxylase, spermidine synthase and S-ad enosylmethionine decarboxylase gene have been generated. Of these anim als those with ornithine decarboxylase transgene show an extensive and constitutive expression of the enzyme in the brain with an exceedingl y high putrescine concentration, a phenotype that is not encountered u nder physiological conditions. In this article we review the neurometa bolic, behavioural and histological data that has been obtained from t hese transgenic mice.