ABSTRACT
Generalized EEG seizures were induced in acute, conscious New Zealand albino rabbits with intravenous pentylenetetrazol (PTZ) (10 or 15 mg/kg) or electrical stimulation of the frontal cerebral cortex (ELEC) (50 Hz, 1 msec pulse duration, 2 sec train duration, 4.0-7.6 V). Three anticonvulsant treatments were compared: (1) electrical transhemispheral stimulation of the ansiform or simplex cerebellar lobes (10 Hz, 1.5 msec, 3-4 V), (2) phenobarbital (PB) (25 mg/kg, i.v.), and (3) diphenylhydantoin (DPH) (30 mg/kg, i.v.). After treatment, increments in PTZ dose or stimulation voltage were applied until a seizure was evoked that approximated the original in severity and duration. PTZ seizure thresholds were not elevated by DPH, and electrically induced seizure thresholds were not elevated by cerebellar stimulation (CBL). The four remaining seizure threshold elevations (increase in PTZ dose or stimulation voltage) were significant at a level of 0.025 or greater. Comparison of the elevations of seizure thresholds showed no differences at the 0.01 level of significance. Thus, no differences were seen between elevation of PTZ seizure thresholds by CBL or PB, or elevation of electrically induced seizure thresholds by PB or DPH, when examined on an acute basis.
Subject(s)
Cerebellar Cortex/physiology , Electric Stimulation , Phenobarbital/therapeutic use , Phenytoin/therapeutic use , Seizures/prevention & control , Animals , Cerebral Cortex/physiology , Electroencephalography , Male , Pentylenetetrazole , Rabbits , Seizures/etiology , Seizures/physiopathologyABSTRACT
A flow chamber has been developed which collects about 60% of the total cell fluorescence for analysis compared to about 2.5% for conventional flow systems. The chamber, an ellipsoid of revolution, is gold-plated for increased reflectivity. Fluorochrome-stained cells enter the flow cell directly above the primary focus of the ellipsoid at the rate of 1000 cell/sec. A focused argon-ion laser beam enters the flow cell parallel to the semiminor axis and intersects the cell stream at the primary focus. Fluorescent light emanating from this point is reflected toward the secondary focus, where it exits the chamber for analysis. The high efficiency flow cytometer has been used to obtain nucleotide fluorescence distributions from samples of Micrococcus glutamicus bacteria stained with propidium iodide and of spermatozoa stained by the acriflavine-Feulgen procedure.
