Mild foot electrical stimulation is comparable with phenytoin in inhibiting pentylenetetrazol-induced kindling in rats.

Increasing evidence demonstrates that electric stimulation has anticonvulsant effects. The present study was undertaken to investigate the effects of mild foot electrical stimulation (MFES) on the development of pentylenetetrazol (PTZ) kindling and compare its effectiveness with the more commonly used treatment, phenytoin. Kindling was induced in rats by repeated injections (every 24 h) of PTZ (37.5 mg/kg). The rats were subjected to either MFES (0.2 mA in intensity for a 160 ms duration with a 160 ms interval for 20 min) or phenytoin (30 mg/kg) before PTZ injections. Following this treatment, rats received MFES every other day for 10 days or 26 days after establishment of PTZ kindling. The data showed that MFES significantly inhibited development of chemical kindling induced by PTZ in rats (p = 0.001, as compared to PTZ-treated animals). This inhibitory effect is comparable with the effect of 30 mg/kg doses of phenytoin (P = 0.99, as compared to phenytoin group). However, 10 days or 26 days durations of MFES had no effect on established kindled seizures (P = 0.58 as compared to PTZ-treated animals). Our data demonstrate that although MFES significantly inhibited the development of chemical kindling, this experimental paradigm had no effect on established kindled seizures.

Low, but Not High, Doses of Copper Sulfate Impair Synaptic Plasticity in the Hippocampal CA1 Region In Vivo.

Previous studies have shown the inhibitory effect of the in vitro application of copper sulfate on hippocampal long-term potentiation. While in vivo administration of copper did not affect spatial learning and memory. To find possible answers to this controversial issue, we evaluate the effect of different doses of copper sulfate on in vivo long-term potentiation, synaptic transmission, and paired-pulse behavior of CA1 pyramidal cells. Thirty-two male Wistar rats were divided into four groups: control, 5, 10, and 15 mg of copper sulfate. Field excitatory postsynaptic potential from the stratum radiatum of CA1 neurons was recorded following Schaffer collateral stimulation in rats. Spike amplitude, long-term potentiation and paired-pulse index were measured in all groups. The results of this study showed that 5 mg/kg copper sulfate increased synaptic transmission and inhibited long-term potentiation and decreased the hippocampal paired-pulse ratio, while 10 and 15 mg/kg copper sulfate did not affect CA1 synaptic transmission properties. Low, but not high, doses of copper sulfate affect synaptic plasticity. This finding may explain the difference between the effect of copper on synaptic plasticity and spatial learning and memory.

Sumatriptan, an Antimigraine Drug, Inhibits Pentylenetetrazol-induced Seizures in NMRI Mice.

Sumatriptan has been used for the acute treatment of migraine attacks. There are many similarities between migraine and epilepsy and the medications used to treat one of these disorders can effectively be used to treat the other. The purpose of this study was to evaluate and compare the anticonvulsant effects of sumatriptan with sodium valproate in NMRI mice. 62 male NMRI mice were divided into 8 groups. The groups consisted of a saline (control) group, 4 intraperitoneally (ip) administered sumatriptan groups (1, 10, 50, and 100 mg/kg, ip), and 3 sodium valproate groups (50, 150, and 300 mg/kg, ip). 20-min after the injection of either saline or one of the drug doses, pentylenetetrazol (100 mg/kg, ip) was injected and seizure parameters were evaluated. The results showed that 300 mg/kg sodium valproate markedly inhibited the seizure stage, whereas none of the sumatriptan doses had any significant effect on this parameter. The latency to stages 2 and 4 of the seizures and the interval between the pentylenetetrazol injection to death was significantly increased by both sodium valproate and sumatriptan.Sumatriptan is commonly used for the treatment of migraine and also has a protective effect against seizures induced by pentylenetetrazol in mice.

Cardiovascular physiology misconceptions and the potential of cardiovascular physiology teaching to alleviate these.

BACKGROUND: Misconceptions are mental models of phenomena that are at variance with accepted scientific models of these phenomena. AIM: The goal of this study was to investigate the prevalence of some misconceptions among students about cardiovascular physiology and to evaluate the effectiveness of cardiovascular physiology teaching in alleviating these misconceptions. METHOD: A descriptive-analytic survey was undertaken with 348 undergraduates from the fields of medicine, nursing, and biology. Students were divided into two groups on the basis of whether they had passed or not taken the cardiovascular physiology course. The students were asked to answer four questions relating to cardiovascular. Descriptive statistic analysis and two-tailed comparison of the proportions was used to analyze their answers. RESULTS: The prevalence of misconceptions about the left ventricular output versus the right ventricular output ranged from 80% to 98%. The misconception about pulse velocity compared with blood velocity in the vessels was 74% to 89%. Between 95% and 99% of answers to the effect of increased resistance on blood flow were incorrect in all groups. Between 69% and 73% of the students had trouble answering the question on parallel resistance and the effect of the removal of one limb on total peripheral resistance. For most of the questions, university lectures had no effect on alleviating these misconceptions. CONCLUSIONS: These results indicate that there is a high prevalence of misconceptions among students about at least four cardiovascular concepts associated with cardiovascular physiology and that teaching has failed to alleviate these misconceptions.