Administration Of Amobarbital Research Articles

Time Perception Following Unilateral Amobarbital Injection in Patients with Temporal Lobe Epilepsy

Estimates of elapsed time were obtained from 53 patients with unilateral temporal lobe epilepsy (Left TLE = 27; Right TLE = 26) following Wada (intracarotid amobarbital) assessment. After resolution of drug effects, patients were asked to estimate how much time had passed since amobarbital administration. Estimates were also obtained from 24 healthy control subjects using the same cognitive tasks over a similar time frame. Elapsed time was significantly underestimated by both left and right TLE groups following right hemisphere injection. In addition, there was an interaction effect involving patient group, side of injection, and sequence of injection. Left TLE patients, consistent with normal controls, made more accurate time estimates when they could anticipate the estimation task following the second amobarbital administration. More accurate time estimates, however, occurred only when left hemisphere injection was second in sequence. In contrast, right TLE patients did not improve regardless of the order of injection. These results suggest that right hemisphere function plays a critical role in the accuracy of time estimations of intermediate temporal duration and that interhemispheric interaction may be required to make accurate retrospective temporal judgments. These findings are discussed in the context of the growing evidence for a right-hemispheric attentional network.

Wada memory and timing of stimulus presentation.

We compared Wada memory performance for stimuli presented at two timing intervals following amobarbital injection in 47 non-lesional patients with complex partial seizures (L = 26; R = 21). A significant interaction between seizure focus and timing of presentation was present (P < 0.03). Memory performance for objects whose presentation began approximately 50-55 s following amobarbital administration differed as a function of ipsilateral vs. contralateral injection at a very high level of statistical significance (P < 0.00001). Items presented approximately 4 min, 30 s post injection were also related to seizure onset literality, but at a lower statistical level (P < 0.01). Presentation of Wada memory stimuli earlier during hemispheric anaesthesia yields results that are more sensitive to lateralized temporal lobe seizure onset than does presentation of items later during the procedure.

Stimulus Timing Effects on Wada Memory Testing

To determine the effects of presenting Wada memory stimuli at different times after intracarotid amobarbital injection on Wada memory asymmetries. Wada memory asymmetries from three timing series were related to the laterality of eventual temporal lobectomy. Academic institution epilepsy surgery program. Forty-three patients with complex partial seizures who later underwent anterior temporal lobectomy (left temporal lobectomy, 24 patients; right temporal lobectomy, 19 patients). No patient included had abnormalities on magnetic resonance imaging scans to suggest a lesion other than gliosis. Memory performance for objects whose presentation began approximately 45 seconds after amobarbital administration differentiated laterality of seizure onset. Memory for items presented later and after partial return of language (on average 3 minutes 40 seconds postinjection) also differed as a function of ipsilateral vs contralateral injection, but at a lower level of statistical significance. Memory for items presented last during the procedure (on average 6 minutes postinjection) discriminated seizure groups at a still lower level of statistical significance. When used to predict lateralized temporal lobe impairment in individual patients, early object memory performance was significantly better than memory performance employing either middle (56%) or late (43%) stimulus presentation timings. The results of early object memory testing are superior to those obtained from stimulus presentation later in the procedure in documenting temporal lobe dysfunction associated with a lateralized seizure onset.

N-Glucosidation of amobarbital in the cat.

N-Glucosidation is a novel pathway of barbiturate metabolism, so far known to occur only in man. A search for an animal model, conducted through in vitro screening, revealed that amobarbital-N-glucoside was formed in liver preparations from the cat. The presence of amobarbital-N-glucoside was demonstrated in cat urine, following i.p. administration of amobarbital.

Effects of stimulus associated with amobarbital administration on avoidance behavior

The present study was concerned with the effect on avoidance responding of superimposing a stimulus which has previously been associated with amobarbital administration. Rats were given unsignaled shuttlebox avoidance training, then given separate Pavlovian conditioning (CS- amobarbital pairings) with avoidance training continuing on alternate days. The Pavlovian CS was then presented during two test sessions to determine its effect on the avoidance response. It was found that the Pavlovian CS through its association with amobarbital suppressed avoidance response rate when presented during nonsignaled avoidance behavior.

Studies on the combination of drugs. V. Effect of 4-hydroxyantipyrine on the metabolism of amobarbital and pentobarbital

When 4-hydroxyantipyrine (HOAT), being the metabolites of aminopyrine and antipyrine, was used together with the soporifics of pyrazolone series of anesthetics, amobarbital or pentobarbital, the metabolism of amobarbital in rat liver slices, and the supernatant of 9000×g fraction of rat and rabbit livers were promoted and the biological half-life was found to be shortened. On the other hand, the metabolsim of pentobarbital, to which being resemble in structure, was suppressed and the biological half-life was also lengthened, and the reverse results to amobarbital has been observed. When HOAT was given 30 min prior to the amobarbital administration, the sleeping period of mice was found to be less shortened than the case amobarbital was administered alone.