[Effect of Fe2O3 nanoparticles on anxiety behavior and nociception in adult male rat]

Iron is an essential element for correct brain function. Iron deficiency changes some behaviors such as anxiety and nociception. Recently, nano-iron, Ferric or ferro oxide [nano-Fe2O3 or Fe3O4], are used in various applications in agriculture, industry and medicine, but their effects on the heath and behavior is not clear. In this study, the effects of Fe2O3 nanoparticles on animal models of anxiety and nociception were investigated. Adult male Wistar rats [mean weight: 200-250 g] were used in 12 groups: 3 control groups [receiving saline 0.9%] and 9 groups received nano-Fe2O3 in doses of 0.2, 1 and 5 mg/kg, intraperitoneally. Elevated plus maze apparatus and hot-plate and tail-flick tests were used to evaluate anxiety and nociception, respectively. Data were analyzed by one-way ANOVA and post hock least significant difference [LSD] and P < 0.05 used as significant level. Fe2O3 nanoparticles with dose addition increased open arm time percent [OAT%] [P<0.05]. Locomotor activity, just in dose of 5 mg/kg, increased pain delay time in both hot-plate [P<0.01] and tailflick [P<0.01] tests. Acute administration of Fe2O3 nanoparticle decreases anxiety behaviors in elevated plus maze and increases an acute pain threshold in both hot-plate and tail-flick tests in rats

[ effect of lecithin consumption during pregnancy and lactation in rats on anxiety and locomotor activity of one month male and female offspring]

Considering the role of cholinergic system in anxiety behaviors and the importance of nutrition during pregnancy and lactation in the neural system activity of offspring the aim of this study is to investigate the effect of lecithin during pregnancy and lactation on anxiety behaviors and locomotor activity of male and female rat offspring. Female rats [average weight 168g] were gavaged during pregnancy and lactation [until day 21] with different amounts of lecithin or with vehicle as follows control 1 [no medication] control 2 [vehicle receivers] and two experimental groups receiving 120 and 240 mg/kg lecithin daily. After gender segregation at 30 days of birth, offspring anxiety was assessed by elevated plus maze test. The number of rats in each group was 6 for both sexes. No significant differences were observed in the anxiety indexes and locomotor activity of offsprings in every genus, compared to the vehicle group. Males receiving lecithin 120 and 240 mg/kg, showed a significant increases in percentage of time spent in the open arm in compared to females [P<0.05 and P<0.01]. Significant difference was observed in locomotor activity between males and females receiving lecithin 240mg /kg [P<0.001]. Although lecithin consumption during pregnancy and laction does not affect the locomotor activity and anxiety behavior of offspring gender can cause varing effects in these animals

[Evaluation of analgesic effect of sesame oil and lecithin diets in hot plate and formalin test on aged male rats]

Sesame oil is applied in physiological research as a solvent. It contains unsaturated fatty acids such as linoleic acid, sesamol and lecithin. In his research effect of dietary sesame oil on pain perception was studied. N-MRI male rats [360 +/- 20 g] were used. Animals divided to two groups: 1] control group and 2] experimental group [three subgroups that ate dietary plats that contain 10% sesame oil for 28, 42 and 56 days respectively and a subgroup ate dietary plats that contain 1% lecithin]. After 28, 42 and 56 days pain was evaluateded by digital hot plate and formalin test. Data was analyzed by one way ANOVA or T- test. Hot plate test: Sesame oil diet decreased pain in the 28, 42, 56 days significantly. Formalin test: Sesame oil diet decreased pain only in 42 days [p<0.02] significantly in early phase. Sesame oil diet decreased pain in the 28 days [p<0.0001] and 42 days [p<0.03] and 56 days [p<0.001] significantly in late phase of formalin test and also we found significant difference between control and lecithin group [p<0.006] in late phase. Hot plate test: Dietary plats [10% sesame oil] decreased acute pain perception in all experimental groups [p<0.03]. Our data indicated that dietary sesame oil could increase pain threshold. It seems that sesame oil lecithin [as a source for acetylcholine] or unsaturated fatty acid [altered plasma membrane properties or PGs metabolism] involve in this pain threshold alternation

[Topical estrogen accelerates wound healing in diabetic rats]

Diabetic ulcers especially foot ulcers and the delay in their healing is a major problem faced by most diabetic patients. Based on data available on the positive role of estrogen in accelerating wound healing, this research aimed at assessing the possible effect of topical estrogen on wound healing in diabetic rats. Sixty-six male wistar rats were divided into two groups [normal and diabetic] and each group was divided into 3 subgroups [control, sham and test]. A circular full- thickness wound with a diameter of 1.5 cm was created on the backs of streptozotocin [stz]- induced diabetic and intact rats. In the test subgroup, the wounds were treated with a daily topical dose of 0.5 mg estrogen and in the sham subgroup, gentamicin ointment [dose 0.5 g] was used. The process of wound healing was assessed by macroscopic and microscopic studies on days 3, 5, 7, 14, 21, and 28. The macroscopic study, showed delays in healing of the diabetic group in comparison with the normal group and after the seventh day, wound healing showed considerable change in the test subgroup in both normal and diabetic rats [p<0.05]. In the normal group microscopic study, the only parameter which did not show any differerence was granulation tissue organization; however increasing of neoangiogenesis and re-epithelization was observed in the test subgroup. Also, in the diabetic group, the estrogen receiving subgroup showed impressive improvement compared to the sham subgroup. Topical that estrogen can accelerate the process healing of diabetic wounds

[Effects of Matricaria Chamomilla extract on morphine withdrawal syndrome in mice]

Matricaria chamomilla [MC] contains flavonoids, which exert benzodiazepine-like activity and so it may be helpful in morphine withdrawal syndrome [MWS] treatment. To determine the effects of MC extract on morphine withdrawal syndrome signs in adult male mice. This was an experimental study carried out in two steps at the department of physiology, Qazvin School of medicine [Iran], in 2005. Step 1: 3 adult male mice [n=6] were originally divided into 2 groups marked as saline [control] and morphine [case] groups. The morphine group were injected by increasing doses of morphine [10, 20, 40 mg/kg, s.c], 3 times daily, for a total duration of 4 days and were further divided into 4 subgroups as morphine group and 3 MC extract groups receiving one dose of MC extract [10, 20 or 30 mg/kg I.P] at day 4, 30 min before naloxone injection. At the end of training day [4[th] days] all groups were injected by naloxone [5mg/kg I.P] and MWS was studied for 30 minutes. Step 2: another 30 adult male mice [n=6] were injected by saline, morphine and MC extracts as above except for morphine and naloxane which were injected as one single dose [50 mg/kg]. Naloxone was injected 3hr after the last injection of morphine and the frequencies of withdrawal behaviors [jumping, climbing] were assessed later. The results of the present study showed that the acute and chronic administration of MC at doses used in our experiment significantly abolished the morphine withdrawal syndrome signs [jumping, climbing, writhing, weight loss] compared with morphine group. Our data suggest that the MC can attenuate the expression of withdrawal behaviors in male mice

[Study on the effect of oxytocin in locus coeruleus on anxiety induced vogel's test in presence and absence of yohimbine in male rat]

Locus coeruleus [LC] nucleus modulates certain physiological behaviors such as pain, anxiety, awake, sleep, memory and learning. Some studies have shown that the LC nucleus has both adrenergic neurons and alpha 2-adrenoceptors, and also receives oxytocinergic projections from the paraventricular nucleus of the hypothalamus. The effect and mechanism of this neuropeptide is not fully understood. Considering that the chronic usage of oxytocin decreases anxiety, in the present study the effect of acute administration of oxytocin in the locus coeruleus and its interaction with alpha 2 adrenoceptors on anxiety induced vogel's test in male adult rats were investigated. Male adult wistar rats weighing 285 +/- 15 grams were divided into 6 groups: 1] Receiving saline, 2] oxytocin [2ng/2micro l], 3] yohimbine [3.3 micro g/2microl], 4] receiving saline + yohimbine, 5] saline+ oxytocin and 6] yohimbine+oxytocin in locus coeruleus nucleus. Number of received shocks during water drinking was evaluated as an anxiety behavior for 15 minutes in Vogel's test. Oxytocin reduced number of shocks received [Anxiogenic effect]. Blocking of alpha 2 adrenoceptors by yohimbine decreased number of shocks received. Anxiogenic effect of oxytocin increased in presence of yohimbine. It seems that the LC alpha 2-adrenoceptors modulate anxiety and the anxiogenic effect of oxytocin and this effect can be eliminated by the blocking of the alpha 2-adrenoceptors

[Study of interaction between oxytocin and opoid system in locus coeruleus on acute pain in the rat]

Studies show that the plaus a role hormone oxytocin in the control of pain, sexual behavior, anxiety and love. The mechanism of this neuropeptide is not completely understood in the CNS. This study aimed at researching the effect of oxytoxin administered in the locus coeruleus [LC] nucleus on pain and its interaction with opioid system, because LC influences the nociception and also contains oxytocin and opioid receptors. Male wistar rats weighing 270 +/- 20 grams were used. Animals divided to the in control group, receiving only oxytocin [3nmol/2 l] and the group receiving oxytocin [3nmol/2microl] with naloxone as an opioid receptor antagonist [3nmol/1microl] in LC nucleus. Hot plate and tail flick tests were used for pain response evaluations. Oxytocin injection in locus coeruleus nucleus induced analgesic effect significantly in two analgesiometer tests [p<0.001]. Naloxone prevented the analgesic effect of oxytocin significantly [Hot plate p<0.001, Tail flick p<0.05]. Oxytocin exerts part of its antinociception effect via LC nucleus and probably by excitation of the opioid system because of the inhibiting effect of naloxone

[ effect of gonadectomy and sex - related differences in response to matricaria chamomilla extract on locomotor activity behavior in mice]

Former studies showed that the Matricaria chamomilla hedroalcholic extract affects pain and anxiety of male and female mice sex-dependently. In this research we examined the effect of Matricaria chamomilla [chamomile] hydroalcholic extract on locomotor activity behavior in presence and absence of sex glands in adult male and female NMRI mice. Animals were divided into groups of seven including intact, sham, gonadectomized and receiving hydroalcholic extract of chamomile [30 and 50 mg/kg i.p]. Motor activity monitor system was used to evaluate locomotor activity parameters [number of line crossing movments, stereotype movments and number of rearing movments] in open field test on all groups. 1] Hydroalcholic extract of chamomile [50 mg/kg dos] decreased motor activity parameters in presence and absence of sex glands in male mice. 2] Hydroalcholic extract of chamomile [50 mg/kg dose] increased motor activity parameters in presence and absence of sex glands in female mice.3] Gonadectomy did not have any effect on locomotor activity parameters on male mice.4] Gonadectomy decreased motor activity parameters on female mice. It seems that chamomile extract influences motor activity parameters via some sex related factors like neurochemical systems in male and female mice. This effect may in part depend on sex hormones receptors in female mice

[ effect of intrafrontal cortex injection of physostigmine on active avoidance learning on the animal model of Alzheimer's disease]

Cholinergic neurons of nucleus basalis magnocellularis [NBM] have a key role in learning and memory process. It has been shown that these neurons are degenerated in patients with Alzheimer disease [AD]. On the other hand, using the cholinomimetic agents and acetylcholinesterase inhibitors improve cognition in these patients. Some studies have shown that the frontal cortex receives some cholinergic projections from NBM. In the present study, the effect of intrafrontal cortex administration of physostigmine [acetylcholinesterase inhibitor] was investigated on active avoidance learning on the animal model of AD. In this experimental study, NBM was lesioned electricaly in Wistar male rats, [250-300g body weight] for making the animal model of AD. Because the frontal cortex receives cholinergic projections from NBM, different doses of physostigmine [2.5, 5, 7.5 microg/microl] were injected bilaterally into the frontal cortex of lesioned rats 20 minutes before active avoidance learning [8 sessions, 30 steps in each session] in Y-maze. The results showned that active avoidance learning was decreased significantly in NBM-lesioned group. Also intrafrontal cortex injection of phsostigmine [2.5, 5, and 7.5 microg/microl] significantly severed NBM lesion-induced learning deficiency. The findings of this study suggest that the cholinergic projection of NBM to frontal cortex in lesioned animals has a negative role on this type of learning. It seems that other neurotransmitter systems such as glutamate and other afferent projections from different brain areas to frontal cortex probably are involved in this phenomenon

[Effect of acute and chronically administrated estradiol benzoate on the withdrawal syndrome in morphine dependent ovariectomized mice]

There is some evidence about the role of estrogen in the nervous system such, as increasing plasticity in different areas of brain and interference phenomena like reproduction, pain and memory. Results of some investigation indicate the neuromodulatory effect of estrogen. In this study, the effect of estradiol benzoate in morphine dependency was investigated. Material and Albino mice weighing 25 +/- 3 grams, were divided to in to control [sham operation], ovariectomized, ovariectomized receiving sesame oil and acute and chronically administrered estradiol benzoate groups. Addiction was induced in all animals by morphine injections 3 times per day, for four days. On the fourth day, half an hour before induction of withdrawal syndrome naloxone, stradiol benzoate were acutely injected [0.1 mg/kg, SC] and jumping of animals as a sign of withdrawal syndrome was assessed. Chronic treatment of estradiol benzoate was co-administered with morphine on four the day. The results showed that ovarectomy decreased jumping activity of withdrawal syndrome or intensity of morphine-dependency and estradiol benzoate treatment partially increased this sign of the withdrawal syndrome although but it was less than the control groups. The results suggest that the other sex related factors probably influence the intensity of morphine dependency

[Effects of paragigantocellularislateralis [LPGi] nucleus electrical lesion on withdrawal syndrome in morphine dependent male rats]

Nucleus paragigantocellularis lateralis[LPGi] involves in several physiological functions such as cardiovascular regulation, sexual behavior and pain. There is little evidence about its role on opiate withdrawal. In this research the effect of LPGi electrical lesion on withdrawal syndrome in morphine-dependent rats was studied.N-MRI rats were divided into three groups: Control, Sham and Lesion group. Animals were anaesthetized using ketamine [110 mg/kg] and rampone[3 mg/kg] mixture injection [i.p].Stainless steel electrodes were placed in LPGi[AP=11.8, L= +/- 1.6, DP=10.5] bilaterally. LPGi was lesioned using electrical current [1 mA, DC] for 6 seconds. After 10 days recovery period animals were addicted by morphine injection two times a day for 4 days [every day 25, 30, 35, 40 mg/kg respectively]. In the fifth day 40mg/kg morphine have been injected to animals and after 30 min withdrawal syndrome was induced by naloxane injection [4 mg/kg i.p] and evaluated withdrawal sign [rearing, ptosis of eye lid, teeth chattering, grooming, wet dog shakes, paw tremor, body tremor, number of ejaculation, defecating, jumping]. Our results showed that LPGi lesion only can decreased ejaculation, paw tremor and wet dog shakes significantly [p<0.02] but LPGi lesion did not affect other withdrawal signs. Our data showed that LPGi altered only ejaculation, paw tremor and wet dog shakes. It seems that LPGi have critical role in those sings and other withdrawal sing related to other nucleus such as PGi and LC

[ effect of electrical lesion of paragigantocellularis lateralis nucleus on acute pain perception in presence of clonidine [alpha2 adrenergic agonist] in rat]

Paragigantocellularis lateralis nucleus [LPGi] involves several functions such as cardiovascular regulation, sexual behavior, withdrawal syndrome and pain. Ln addition, the role of a2 adrenergic in analgesia has been reported as well. We studied the role of a2 adrenergic receptor in LPGi on acute pain. After surgical process LPGi was lesioned bilaterally by using electrical DC current [1mA, 6 second], at stereotaxic coordinates of [AP=11.8, Lat.+/-l.86 and Depth=10.5]. Pain perception was tested using a standard hot plate. No significant difference was found between the control group and the sham group. There is a significant difference between the sham group and lesion+saline group [P<0.0002]. There are significant differences between the lesion+saline group and lesion+0.02 mg/km clonidine [P<0.001] as well as lesion+saline group and lesion+0.2 mg/km clonidine [P<0.001]. We conclude that a2 adrenergic receptors of LPGi nucleus not only have a major role in the clonidine induced analgesia but also may be affecting other parts of CNS to induce analgesia in rat

[Preventive effect of hydroalcoholic extract of matricaria chamomilla on nicotine induced convulsions in mice]

Background and Objective: Convulsions are the most important symptom of generalized epileptic attacks, a neurological disorder in which many people of different societies are suffering from it. Because of the side effects and toxicity of the synthetic drugs, nowadays herbal medicines are used in the treatment of convulsions. This study was performed to survey the anti convulsion effect of the hydroalcoholic extract of Matricaria Chamomilla on Nicotine induced convulsions in mice

Methods: In dose-response study, different doses for the extracts [500, 600, 800 and 1000 mg/kg] were injected to test groups [Each group 8 animals] intraperitoneally, and control group received normal saline [1ml/100g IP]. After 30 minutes, nicotine [5 mg/kg] was given to all groups [IP] and the time for onset, duration and intensity of the convulsions were recorded. In time-response study, the most effective dose of extract [1000 mg/kg] and normal saline were administered 0, 15, 30, 45 and 60 minutes before nicotine injection, respectively and time for onset, duration and intensity of convulsions were recorded

Findings: Results of dose-response showed that 600, 800 and 1000 mg/kg of extract increasing time for onset and decrease duration of convulsions. The results of time-response showed that, the time for onset, duration and intensity of convulsions, increased, decreased and decreased for 15, 30, 45 and 60 minutes, respectively

Conclusion: Results obtained from this study showed hydroalcoholic extracts of Matricaria Chamomilla has anti convulsions effect. In order to know the mechanism of action of extracts, it needs more study on different animals models

effect of clonidine on chorda tympani neural response to salt and sweet tastes in the rat

Two commonly used tastants, sucrose and sodium chloride, were applied to the tongue surface of rats while recording was made from their gustatory peripheral nerve, chorda tympani [CT]. This multiple unit recording was performed in the presence of different doses of clonidine, an antihypertensive drug. Clonidine, in low doses [0.15, 0.25 mg/kg, intraperitoneally] caused a significant decrease in the relative integrated neural responses of the rats' CT to NaCl [0.1 M] and sucrose [0.5 M] as compared to the reference solution [NH4Cl] [p<0.05]. In these doses clonidine did not act selectively in response to these special tastants, but in higher doses [0.5 mg/kg], it attenuated the nerve response to sucrose, while no effect was elicited on the response to NaCl