Jun-ichi Miyahara

Learn More
1. Monosynaptic excitatory post-synaptic potentials (EPSPs) produced in spinal motoneurones of the cat by stimulation of a single afferent fibre were recorded with intracellular electrodes.2. In total, seventy-three triceps surae motoneurones were studied with stimulation of thirty-six different afferent fibres.3. The mean amplitude of the EPSPs evoked by(More)
The 1.5-benzodiazepine (clobazam), the 1,4-benzodiazepine (diazepam), and two nonbenzodiazepine antiepileptic drugs (phenobarbital and valproate) were evaluated in mice and rats with a battery of well-standardized anticonvulsant test procedures. The results obtained indicate that clobazam and valproate exhibit a wider range of experimental anticonvulsant(More)
The effects of ciguatoxin (CT) and maitotoxin (MT) were studied on the isolated atria of the guinea pig. Application of CT evoked a prolonged positive inotropic effect on the electrically-driven atria and both inotropic and chronotropic effects on the spontaneously-beating right atria. The response to MT in contrast was biphasic. At low concentration(More)
1. Hyperpolarization following single and repetitive excitation of dorsal spinocerebellar tract (DSCT) neurones of the cat was studied by intracellular recording.2. Hyperpolarization following an antidromic action potential consisted of an initial, brief phase (undershoot) and a late, prolonged phase. The latter hyperpolarization was independent of the(More)
1. The effects of salicylate on oxidative phosphorylation and respiration were investigated in liver and brain mitochondria, and in sonically prepared mitochondrial fragments. 2. Salicylate was shown to uncouple oxidative phosphorylation in mitochondrial fragments, as well as in intact mitochondria. The effects of salicylate on mitochondria and oxidative(More)
Moderate correlation was shown between the following tests: RIA: mouse bioassay (r = 0.58); RIA: guinea pig atrium assay (r = 0.62); guinea pig atrium assay: mouse bioassay (r = 0.62). All three assay procedures showed good correlation when ciguatoxin was present in tissues in high concentrations. The results also suggest that more than one structurally(More)
Myripritis sp. (squirrelfish) has been assessed for toxicity by 1) the stick-enzyme immunoassay (S-EIA); 2) mouse toxicity bioassay; and 3) guinea pig atrial assay. Analysis of Myripristis flesh with MAb-CTX and MAb-OA showed that with every fish examined, the reaction with MAb-OA was considerably higher. The mean S-EIA value for MAB-OA was 2.9 +/- 0.8(More)
The stick enzyme immunoassay (S-EIA) using monoclonal antibody to ciguatoxin (MAb-CTX) was used to examine clinically implicated fish and to pre-screen two species of fish, Caranx sp. (ulua or jack) and Seriola dumerili (kahala or amberjack), supplied by sports fishermen. All of the clinically implicated fish from the Department of Health gave S-EIA values(More)