sodium-nitrite and Amnesia

To investigate the effect of bacosides (alcoholic extract of brahmi) on scopolamine (3 mg kg(-1), ip), sodium nitrite (75 mg kg(-1), ip) and BN52021 (15 mg kg(-1), ip) induced experimental amnesia in mice, using Morris water maze test, all the agents were administered 30 min before the acquisition trials on each day and repeated for 4 consecutive days, and on 5th day during the retrieval trials. Bacosides on anterograde administration (before training) in mice, significantly decreased the escape latency time (ELT) during the acquisition trials for 4 consecutive days and increased the time spent (TS) in target quadrant during the retrieval trials on 5th day, and on retrograde administration (after training) bacosides were found not to affect TS significantly. Bacosides also significantly decreased the ELT and increased the TS in mice treated anterogradely with scopolamine and sodium nitrite. Bacosides did not exhibit any significant effect on TS of mice treated retrogradely with sodium nitrite. On the other hand, bacosides significantly increased the TS of mice treated retrogradely with BN52021. On the basis of the present results it can be concluded that bacosides facilitate anterograde memory and attenuate anterograde experimental amnesia induced by scopolamine and sodium nitrite possibly by improving acetylcholine level and hypoxic conditions, respectively. Beside this bacosides also reversed BN52021 induced retrograde amnesia, probably due to increase in platelet activating factor (PAF) synthesis by enhancing cerebral glutamate level.

Topics: Amnesia; Animals; Bacopa; Diterpenes; Female; Ginkgolides; Lactones; Male; Maze Learning; Memory; Mice; Phytotherapy; Plant Extracts; Saponins; Scopolamine; Sodium Nitrite; Triterpenes

The effect of a standardised 50% ethanolic extract of Indian Hypericum perforatum (IHp) was investigated for its putative nootropic activity on various experimental paradigms of learning and memory, viz. transfer latency (TL) on elevated plus-maze, passive avoidance (PA), active avoidance (AA), scopolamine and sodium nitrite induced amnesia (SIA & NIA) in albino rats. Pilot studies indicated that single dose administration of IHp had little or no acute behavioural effects, hence the extract of IHp was administered orally at two dose levels (100 and 200 mg/kg, p.o.), once in daily for three consecutive days, while piracetam (500/kg, i.p.), a clinically used nootropic agent, was administered acutely to rats as the standard drug. Control rats were treated with equal volume of vehicle (0.3% carboxymethyl cellulose (CMC)). IHp and piracetam when given alone shortened the TL on day 1, 2, 9 and also antagonised the amnesic effects of scopolamine and sodium nitrite on the TL significantly. IHp had no significant per se effect on the retention of the PA in rats. Only the higher dose (200 mg/kg, p.o.) produced a significant reversal of scopolamine induced PA retention deficit but no significant reversal was observed with sodium nitrite. Piracetam showed significant per se facilitatory effect on PA retention and also reversed the scopolamine and sodium nitrite induced impaired PA retention. In the AA test, IHp in both the doses, and piracetam, facilitated the acquisition and retention of AA in rats and the IHp effects were found to be dose dependent. Both the doses of IHp and piracetam significantly attenuated the scopolamine and sodium nitrite induced impaired retention of AA. These results indicate a possible nootropic action of IHp, which was qualitatively comparable with that induced by piracetam.

Topics: Amnesia; Animals; Anxiety; Avoidance Learning; Cognition Disorders; Female; Hypericum; India; Male; Muscarinic Antagonists; Nootropic Agents; Phytotherapy; Plant Extracts; Plants, Medicinal; Rats; Scopolamine; Sodium Nitrite

Taurine was extracted from Pegasus laternarius Cuvier to study its effects on learning and memory in mice. Mice were treated with different doses of taurine (10 mg/kg, 20 mg/kg, 40 mg/kg). The mice were treated with various chemical agents (pentobarbital, cycloheximide, sodium nitrite, alcohol) to disrupt the normal memory process. We measured the effect of taurine on step-down latency (SDL) and escape latency (EL) in a passive avoidance task after 10 or 30 days. Treatment with taurine alone did not change either SDL or EL. Taurine protected mice from the memory disruption induced by alcohol, pentobarbital, sodium nitrite, and cycloheximide but had no obvious effect on motor coordination, exploratory activity, or locomotor activity as measured using the rota-rod test and the hole board test. We conclude that taurine can be effective in attenuating the amnesia produced by alcohol, pentobarbital, cycloheximide, and sodium nitrite without compromising the behavioral aspects of the animals tested.

Topics: Amnesia; Analysis of Variance; Animals; Avoidance Learning; China; Cycloheximide; Ethanol; Medicine, Chinese Traditional; Memory; Mice; Mice, Inbred BALB C; Motor Activity; Pentobarbital; Plants, Medicinal; Psychomotor Performance; Sodium Nitrite; Taurine

Topics: Amnesia; Animals; Male; Memory; Mice; Nifedipine; Nimodipine; Rats; Rats, Inbred Strains; Scopolamine Derivatives; Sodium Nitrite; Vinca Alkaloids; Vincamine

Graded doses of sodium nitrite were administered shortly before or immediately after a single training trial in an inhibitory avoidance task. A retention test was given at 24 h (rats) or 72 h (mice) after training. The results indicate that sodium nitrite impairs acquisition of an inhibitory avoidance response in rats and mice. Retention was impaired with doses lower than those required for producing hypoxic effects, as measured by the EEG, methemoglobin levels in the blood, blood pressure, and heart rate. Since hypoxia was not involved, it is likely that the effects were mediated by some direct action of sodium nitrite on the CNS.

Topics: Amnesia; Animals; Avoidance Learning; Blood Pressure; Central Nervous System; Dose-Response Relationship, Drug; Electroencephalography; Heart Rate; Humans; Injections, Intraperitoneal; Male; Memory; Methemoglobin; Mice; Nitrites; Rats; Sodium Nitrite; Species Specificity; Time Factors