STUDIES ON Β-Pyridylcarbinol AS a PRECURSOR OF NICOTINAMIDE ADENINE DINUCLEOTIDE

Abstract

Krupp and Monnier (1) have demonstrated that anticonvulsants affect the non-specific thalamo-cortical system which plays an essential role in the pathophysiology of epilepsy.From this point of view, we have studied the involvement of anticonvulsants in cortical excitability by examining the action on cortical focal seizure (2). We found that trimethadione differed from diphenylhydantoin in the mode of action. In the present experiments, attention was directed to the thalamus, the other part of the thalamo-cortical system, and effects of anticonvulsants were determined on the afterdischarge in cats and rats. There are apparently few pharmacological reports on thalamic afterdischarge since studies by Schallek et al. (3) and Gangloff and Monnier (4). In addition, there appear to be species differences regarding the anticonvulsive effects of the drugs (3-6) and it has yet to be elucidated whether drug-induced change in thalamic afterdischarge is associated with the control of generalized seizure. A preliminary report of these findings has been summarized (7). MATERIALS AND METHODSCats of both sexes weighing 2.5 to 4.0 kg and male rats (Wistar HLA strain) weighing 250 to 380 g were used.All surgical procedures were carried out under ether anesthesia.Cat-, The animal was fixed on a stereotaxic apparatus (Todai Noken type), immobilized with

Thalamic generalized seizure induced by tungstic acid gel in cats and its suppression by anticonvulsants.

“…In this study, since the gel-induced GS was found to be an epileptic model more closely related to grand mal epilepsy, the drugs effective against grand mal epilepsy would expectedly act more effectively in the case of this particular model. In the present study, the doses of diphenylhydantoin and phenobarbital required to decrease the occurrence of GS were the same or lower than those effective in the case of other models (12- 16,25). The role of the thalamus in epilepsy cannot be clearly determined on the gel-induced thalamic GS.…”

“…Diphenylhydantoin and phenobarbital evenly suppress not only the thalamic but also the cortical seizures (12)(13)(14)(15)(16)25). In addition, the cortical and thalamic structures are anatomically related to and physiologically inter-controlled.…”

Comparison of the (Pro)convulsive Properties of Fluvoxamine and Clovoxamine with Eight Other Antidepressants in an Animal Model

“…However, convul sions also occur at therapeutic doses, especially in pa tients with already decreased seizure thresholds [Toone and Fenton, 1977]. A variety of animal models have been developed to determine the (pro)convulsive potency of drugs by determining their effects on: -thalamic discharges in rats and cats [Ito et al, 1977]; -photically evoked afterdischarges in hooded rats [Big ler. 1977]; -seizure activity in photosensitive baboons (Trimble et al, 1977;Meldrum et al" 1982]; -afterdischarges induced by electric stimulation of the rabbit amygdala [Ossows/ca and Wolfarth, 1980;Sayers, 1979] or the rat amygdala [Kamei et al, 1975]; -spontaneous EEG in locally anesthetized cats immo bilized with gallamine [Koella et al, 1979] or nonanesthetized, noncurarized rabbits [Tartara et al, 1982]; -hippocampal afterdischarges in rabbits [Tartara et al, 1982], Contradictory results have been reported by various authors using the same methods.…”

Effect of Anticonvulsants on Spiking Activity Induced by Cortical Freezing in Cats

“…In the present study, the effects of an-ticonvulsants on SA induced by cortical freezing which reliably produces discrete active foci of epileptic discharges (Stalmaster and Hanna, 1972) were examined in cats. A preliminary report on these findings has been made (Hori et al, 1977).…”