Neurotransmitters, Seizures, and Epilepsy III

The polyamines are present in high concentrations in mammalian and nonmammalian brain, where they seem to play a modula-tory or transmitter role (31, 35). Several experiments have been carried out during the last decade, but the functional role played by the single polyamines is still not completely clear. The central properties of spermidine and spermine seem qualita-tively the same, except that spermine usually acts at lower con-centrations (35). Putrescine also produces some of the effects of spermidine and spermine at higher doses (35). Convulsions and other central effects of polyamines can be observed with systemic high doses (33). Since there is a blood-brain barrier: to the polyamines (11), it was reasonable to suppose that direct microinjection into the brain would be a more appropriate method of administering the polyamines when studying their central actions. In previous experiments we have reported that putrescine, precursor of spermidine and spermine, given into the third cerebral ventricle in chicks produces dose-dependent behavioural stimulation, increase in locomotor activity with repeated crisis of circling or escape responses, vocalization, side to side head-neck jerks, tachypnoea, clonic convulsions and ataxia (21). In order to better characterize the central effects of polyamines we have studied behavioural, electrocortical (ECOG) and spectrum power effects of putrescine, spermidine and spermine after their microinfusion into several areas of the rat brain. Since almost similar motor signs observed after polyamines