Effect of extremely low frequency electromagnetic fields on dtrychnine-induced-convulsions in mice

Effects of electeromagnetic exposure on different parts of neruous system and memory of humans and animals has been established. In spite of important human studies, animal studies have been more precise and comprehensive. Extremely low frequency electromagnetic fields [ELF, <300Hz], have been reported to induce a variaty of behavioral and physiological function changes in animals. The object of present study was to determine the delay and durartion time of convulsions induced by co- exposure of ELF and strychnine. The effects of ELF on convulsions induced by strychnine [1mg/Kg] were investigated in 60 albino mice. Animals were devided into 6 groups [n=10], including control [I], 100Hz and 20Volt [II], 25Hz and 20Volt [III], 25Hz and 260Volt [IV], 100Hz and 260Volt [V], and 100Hz and 260Volt [VI]. Delay time [Det] and duration time [Dut] of convulsions were measured respectively. Increase and decrease in Det and Dut were determined and were compared in control and five ELF exposed groups. There was no significant difference in Det and Dut parameters between control [I] and III, IV and VI groups. In all these groups the convulsions terminated in animal death after a low Dut. In contrast there was a significant difference [P<0.001] in Det parameters between control [I] and the other groups [II and V]. No deaths happened in groups [II and V]. Co-exposure of higher ELF frequency and strychnine may decrease the epileptic effects of the drug

Effect of trachyspermum copticum [L.] link microinjection in nucleus reticularis paragigantocellularis on morphine's withdrawal syndrome sings

Drug addiction is destructive misfortune and one of the most important problems in the world. Using the medical plants in medicinal history has valuable information and experiments in this field. According to research Trachyspermum copticum L. T. Copticum is effective in reducing of morphine's withdrawal syndrome, so in this study we investigate the effects of T. Copticum microinjection on nucleus reticularis paragigantocellularis [PGi] on morphine's withdrawal syndrome sings [MWSS]. After preparing the T.C fruit from height of the mountain in Khuzestan, aqueous extract of different concentration [Diluted 10, 100, 1000 times] was prepared by suckcele display. 32 male rats [Sprague Dawley with average weigh 250 - 300 gr] were randomized divided to 4 groups which dependent by intraperitoneum [I.P] injection with morphine. After cannulating the PGI with using the set of steriotaxi, microinjection of different doses of T. Copticum in PGI was done and naloxan [5 mg/kg] was injected I.P to groups. Withdrawal syndrome signs [diarrhea, rearing, ptosis, irritability, tremor, agitation] were observed in 4 groups. Data evaluation and analysis was done by t-test and Mann-Whitney. Results show that T.C was significantly effective in reduction of MNSS such as [rearing ptosis, irritability] compared with control group. T. Copticum is probably sensitive on specific receptors in PGI

[ effect of cinnamon on glucose concentration of diabetic rats in presence or absence of insulin]

Some plants and their aqueous extracts are used as traditional treatments for, diabetes. Cinnamon as a preferred candidate shows anti-diabetic and hypoglycemic effects. To determine the effect of cinnamon extract on blood glucose level of diabetic -rats. The present work was an experimental study in which seventy NMRI male rats[180-250gr] were divided into 2 major groups named as normal and diabetic group. Normal group was further subdivided as control, cinnamon and insulin subgroups in which the latter two received suspensions of cinnamon 60mg/kg per day and intraperitoneal injections of insulin [5micro g/kg], respectively. In four diabetic subgroups, diabetes was induced by ip injection of streptozotocin [40mg/kg]. These groups were marked as diabetic control, diabetic/cinnamon, diabetic/insulin and cinnamon plus insulin subgroups. Our results showed that the oral administration of cinnamon had not significant effect on normal cinnamon subgroup. Insulin injection in normal rats reduced glucose concentration from99.1to 52.1mg/dl. Glucose concentration in diabetic groups with treatment of cinnamon, Insulin and both of them were measured 121.6, 69.6 and 41.4 mg/dl, respectively. Reduction of glucose concentration in these subgroups show a significant change in comparison with control diabetic subgroup, 366.5 mg/dl [p<0.001].Cinnamon can reduce blood glucose concentration in diabetic rats and it seems that the cinnamon effect to be probably linked with potentiating action of cinnamon on insulin

[Noxious behaviours from injection of formalin and morphine tolerance of addicted male rats]

Background: formalin as a chemical noxious stimulus evokes biphasic pain that its latter phase as a chronic inflammation pain is similar to clinical pain

Objective: assessment of noxious behaviours from subcutaneous injection of formalin and morphine tolerance effects on the responses of addicted male rats

Methods: flinching and licking behaviours scored as quantitative pain. Experiments were carried out in normal and morphine addicted rats. Behaviour scores measured quantitative after injection of formalin in plantar region of hind paw. Assessment of morphine tolerance was carried out by intrapritoneal injection of morphine [10mg/Kg] 10 minute before formalin injection

Findings: in this study, we observed biphasic model of formalin test. Morphine injection in normal animals supressed noxious behaviours. Flinching and licking responses evoked by formalin not affected by morphine injection. Licking scores in addicted rats have significant difference from normal rats [p<0.05]

Conclusion: addicted rats showed tolerance to morphine analgesia after formalin injection. Hyperalgesic effects of formalin injection observed in addicted rats

effect of morphine injection in the priaqueductal gray matter on the neuronal responsiveness of nucleus reticularis paragigantocellularis to formalin

Nucleus reticularis paragigantocellularis [PGi] has a very effective role in the supraspinal pain modulation. PGi as a rostroventromedial medulla [RVM] structure receives a major input from periaqueductal gray matter [PAG].Formalin as a peripheral noxious stimulus has biphasic nociception and behavioural manifestations. To assess morphine injection in the priaqueductal gray matter[PAG] on the neuronal responsiveness of nucleus reticularis paragigantocellularis [PGi] to formalin. The experimental subjects were male NMRI rats. Diluted formulin [2.5%] as a chemical noxious stimulus and morphine as an analgesic drug were used. Using single unit recording [an extracelluar recording electrophysiologic method] the research was done. Findings indicate that the responses of the PGi inhibitory neurons evoked by formalin were disinhibited by morphine microinjection in the FAG. In the excitatory neurons, morphine decreased the firing rate to the baseline activity. PGi inhibitory neurons are affected by the PAG's GABAergic interneurons. Morphine blocks GABA released from these intenneurons and results to off- cell disinhibition. On- cells suppressions are probably related to morphine effects directly

Effects of formalin as a peripheral noxious stimulus on the nucleus reticularis paragigantocellularis neurons of ansethetized rats

In the present study, the effects of formalin as a peripheral noxious stimulus on spontaneously active units of the nucleus reticularis paragigantocellularis [PGi], a narrow region of the ventral pontine reticular formation, was examined in urethane anesthetized rats. Spontaneous discharge of the PGi neurons was variable, ranging from I to 37 spikes per second. Formalin as a chemical irritant and prolonged noxious stimulus induced changes in the firing of spontaneously active PGi neurons. There were three neuronal subpopulations in the PGi that responded to formalin: excited [19.35%], inhibited [45.16%] and unchanged [35.48%]. Thus we suggest that PGi neurons may be involved in the processing of information related to formalin as a chemical irritant