Effect of prenatal immobilization stress on spatial memory, anxiety-like behavior and brain BDNF concentration in the F1 generation male mice

Background and Aim: In this study, we investigated the effect of immobilization stress during pregnancy on the spatial memory, anxiety-like behavior and brain BDNF level in F1 generation male NMRI mice

Materials and methods: Twenty female pregnant mice were randomly divided into stress and control groups. The stress group received stress using a restraint cylinder [6 cm ID, 20 cm L] 60 min/day from the 1st to the 15th day of pregnancy. The control group did not receive stress. The male F1 offspring was nursed by their mothers [n=10/group] until reaching weights between 20 and 25 g. Then they were tested for spatial memory using Barnes maze and anxiety-like behavior by the elevated plus-maze. Also, brain BDNF level was measured by means of an ELISA reader

Results: Barnes maze test results showed that the time and distance to reach the target hole were significantly [p<0.001] increased in the stress group. Also, the number of errors and anxiety-like behavior in the stress group were significantly [p<0.001] increased compared to those in the control group [p<0.001]. BDNF level in the brain was significantly [p<0.05] higher in the control group

Conclusion: The present study indicated that prenatal stress can lead to decreased level of BDNF in the brain of the offspring which may result in spatial memory disorder and anxiety-like behavior

Effects of Topical Tamoxifen on Wound Healing of Burned Skin in Rats

BACKGROUND: This study aimed to assess the effects of the topical application of tamoxifen on wound healing of burned skin in Wistar rats by evaluating 3 healing characteristics: fibrotic tissue thickness (FTT), scar surface area (SSA), and angiogenesis in the healed scar tissue. METHODS: Eighteen male Wistar rats were used in this study. A third-degree burn wound was made on the shaved animals’ back, measuring 2×2×2 cm. In the first group, a 2% tamoxifen ointment was applied to the wound twice daily for 8 weeks. The second group received a placebo ointment during the same period. The third group did not receive any treatment and served as the control group. RESULTS: The median (interquartile range=[Q1, Q3]) FTT was 1.35 (1.15, 1.62) mm, 1.00 (0.95, 1.02) mm, and 1.25 (0.8, 1.5) mm in the control, tamoxifen, and placebo groups, respectively (P=0.069). However, the FTT in the tamoxifen group was less than in the placebo and control groups. The median angiogenesis was 3.5 (3.00, 6.25), 8.00 (6.75, 9.25), and 7.00 (5.50, 8.25) vessels per high-power field for the control, tamoxifen, and placebo groups, respectively (P=0.067). However, the median angiogenesis was higher in the tamoxifen group than in the control group. No significant difference was observed in the mean SSA between the tamoxifen group and the control group (P=0.990). CONCLUSIONS: Local application of tamoxifen increased angiogenesis and decreased the FTT, with no change in the SSA in burned skin areas. These effects are expected to expedite the wound healing process, reducing contracture and preventing hypertrophic scar and keloid formation.

Effects of Topical Tamoxifen on Wound Healing of Burned Skin in Rats

BACKGROUND: This study aimed to assess the effects of the topical application of tamoxifen on wound healing of burned skin in Wistar rats by evaluating 3 healing characteristics: fibrotic tissue thickness (FTT), scar surface area (SSA), and angiogenesis in the healed scar tissue. METHODS: Eighteen male Wistar rats were used in this study. A third-degree burn wound was made on the shaved animals’ back, measuring 2×2×2 cm. In the first group, a 2% tamoxifen ointment was applied to the wound twice daily for 8 weeks. The second group received a placebo ointment during the same period. The third group did not receive any treatment and served as the control group. RESULTS: The median (interquartile range=[Q1, Q3]) FTT was 1.35 (1.15, 1.62) mm, 1.00 (0.95, 1.02) mm, and 1.25 (0.8, 1.5) mm in the control, tamoxifen, and placebo groups, respectively (P=0.069). However, the FTT in the tamoxifen group was less than in the placebo and control groups. The median angiogenesis was 3.5 (3.00, 6.25), 8.00 (6.75, 9.25), and 7.00 (5.50, 8.25) vessels per high-power field for the control, tamoxifen, and placebo groups, respectively (P=0.067). However, the median angiogenesis was higher in the tamoxifen group than in the control group. No significant difference was observed in the mean SSA between the tamoxifen group and the control group (P=0.990). CONCLUSIONS: Local application of tamoxifen increased angiogenesis and decreased the FTT, with no change in the SSA in burned skin areas. These effects are expected to expedite the wound healing process, reducing contracture and preventing hypertrophic scar and keloid formation.

Effects of memantine, an NMDA antagonist, on metabolic syndromes in female NMRI mice

Introduction: The brain glutamate neurotransmitter system and its NMDA [N-methyl D-aspartate] receptors in the nucleus accumbens play an important role in the incidence of sensitivity and addiction. The present study examined the inhibitory effect of glutamate NMDA receptors in the nucleus accumbens in response to chronic stress

Methods: After the unilateral and bilateral placement of cannula[e] in the nucleus accumbens, one group of the animals received different doses of intra-accumbens memantine [0.1, 0.5 and 1 micro g per mouse] 5 minutes before receiving the electric shock stress at their soles [using a Communication Box] and the other group received intraperitoneal memantine [doses of 0.1, 0.5 and 1mg per kg] 30 minutes before receiving the same shock. Chronic stress increased the animals' weight, plasma corticosterone, food and water intake, but reduced their defecation rates and eating latency

Results: The intraperitoneal administration of memantine increased plasma corticosterone, water intake, fecal weight, and eating latency, but had no effect on food intake or weight. The dose and site-dependent intra-accumbens administration of memantine either exacerbated the effects of stress on plasma corticosterone levels, water and food intake, or had no effect on these parameters. Furthermore, the administration of memantine had no effect on animal's weight and inhibited the effects of stress on fecal weight and eating latency

Discussion: The inhibition of glutamate NMDA receptors in the nucleus accumbens can inhibit and/or exacerbate the dose and site-dependent effects of chronic stress, and gender plays a significant role in producing this effect too

effects of Fifa 2015 computer games on changes in cognitive, hormonal and brain waves functions of young men volunteers

Introduction: Computer games have attracted remarkable attentions in general publics with different cultures and their effects are subject of research by cognitive neuroscientists. In the present study, possible effects of the game Fifa 2015 on cognitive performance, hormonal levels, and electroencephalographic [EEG] signals were evaluated in young male volunteers

Methods: Thirty two subjects aged 20 years on average participated mutually in playing computer game Fifa 2015. Identification information and general knowledge about the game were collected. Saliva samples from the contestants were obtained before and after the competition. Perceptive and cognitive performance including the general cognitive health, response delay, attention maintenance, and mental fatigue were measured using PASAT test. EEG were recorded during the play using EEG device and analyzed later using QEEG. Simultaneously, the players' behavior were recorded using a video camera. Saliva cortisol levels were assessed by ELISA kit. Data were analyzed by SPSS program

Results: The impact of playing computer games on cortisol concentration of saliva before and after the game showed that the amount of saliva plasma after playing the game has dropped significantly. Also the impact of playing computer games on mental health, before and after the game indicated that the number of correct answers has not changed significantly. This indicates that sustained attention has increased in participants after the game in comparison with before that. Also it is shown that mental fatigue measured by PASAT test, did not changed significantly after the game in comparison to before that. The impact of game on changes in brain waves showed that the subjects in high activity state during playing the game had higher power of the EEG signals in most of the channels in lower frequency bands in compared to normal state

Discussion: The present study showed that computer games can positively affect the stress system and the perceptual-cognitive system. Even though this impact was not significant in most cases, the changes in cognitive and hormonal test and also in brain waves were visible. Hence, due to the importance of this matter, it is necessary to create control systems in selecting the types of games for playing

Effect of transient inactivation of ventral tegmental area on the expression and acquisition of nicotine-induced conditioned place preference in rats

Nicotine can activate dopaminergic neurons within the ventral tegmental area [VTA]. However, there is no evidence about complete inhibition of VTA on nicotine reinforcement. In the present study, we used conditioned-place preference [CPP] method to study the effect of transient inhibition of left and/or right side of the VTA by lidocaine on nicotine reward properties. Male Wistar rats seven days after recovery from surgery and cannulation were conditioned to nicotine [1.5 mg/kg] in an unbiased designed CPP apparatus. Five min before each nicotine injection in conditioning phase, lidocaine [2%] was administered either uni- or bi-laterally into the VTA [0.5 micro l/rat]. Results revealed that lidocaine administration into the left but not right side of the VTA reduced nicotine CPP significantly. The reduction was potentiated when lidocaine injected in to both sides of the VTA. In addition, the number of compartment crossing was reduced when lidocaine injected in both side of VTA as well as left side. On the other hand, rearing was reduced when lidocaine injected to the right but not left side of VTA. At last, sniffing was reduced only in the group in which received lidocaine in both side of VTA. Sniffing and rearing increased in the group in which received lidocaine in right side. It is concluded that the right and left side of VTA play different role in nicotine-induced activity and reward

[Effect of memantine administration within the nucleus accumbens on changes in weight and volume of the brain and adrenal gland during chronic stress in female mice]

In the present study, we examined the effects of memantine administration within the nucleus accumbens on the alterations in brain and adrenal volumes and weight ratios induced by stress from electric foot shock. A group of mice received various doses of memantine [0.1, 0.5 and 1 mg/kg] prior to induction of stress. Another group underwent intra-accumbal cannulation after anesthesia. One week later, memantine [0.1, 0.5 and 1 micro g/mouse] was injected within the nucleus accumbens prior to induction of stress. Subsequently all animals were killed. Their brains and adrenal glands were removed and fixed in 4% formalin. The volume and weight was determined by mercury immersion and method respectively. The stress group showed evidence of reduction in brain volume and weight ratio to volume, and weight of the adrenal gland. Memantine increased the ratio of the brain volume and weight to the volume and weight of the adrenal gland. Memantine administration within the nucleus accumbens also could alter this ratio. Hence, all three doses of memantine that were injected on the right side and bilateral to the nucleus inhibited the effects of stress. Inhibition of NMDA receptors in the nucleus accumbens can inhibit the destructive effects of chronic stress on brain volume and weight. In addition, memantine can inhibit the influence of stress on adrenal volume and weight. We have shown that this effect was both dose and injection site dependent. In this regard, the left side of the nucleus was weaker

Effect of 5Hz electromagnetic waves on movement behavior in male wistar rats [in vitro]

Various stresses during life can affect metabolism and brain activities, immune and endocrine systems directly and indirectly, and ultimately, causes animal behavior change. The cellular and molecular level change in neurotransmitter and hormone concentrations led to the functional changes of operating systems in the intracellular organelles. These events cause of course oxidative stress. All these reactions cause general or limited inflammation that is characterized by increased phenomena of inflammatory cytokines. Electromagnetic waves are the most important stimulus of ions and biomolecules therefore they change ions movement in a living organism. This process can lead to neuronal and behavioral changes. Yet, certainly, radiation pattern, intensity and magnetic field strength will be highly effective in response [reaction]. In the present study, short-term [one day] and medium-term [3 days and 7days] and long-term [19 days and 21 days] effects of extremely low-frequency waves [ELF] on behavioral and metabolic activities in male wistar rats with an average weight 180-250g have been investigated

Effects of Electromagnetic Radiation Exposure on Stress-Related Behaviors and Stress Hormones in Male Wistar Rats

Studies have demonstrated that electromagnetic waves, as the one of the most important physical factors, may alter cognitive and non-cognitive behaviors, depending on the frequency and energy. Moreover, non-ionizing radiation of low energy waves e.g. very low frequency waves could alter this phenomenon via alterations in neurotransmitters and neurohormones. In this study, short, medium, and long-term exposure to the extremely low frequency electromagnetic field (ELF-EMF) (1 and 5 Hz radiation) on behavioral, hormonal, and metabolic changes in male Wistar rats (250 g) were studied. In addition, changes in plasma concentrations for two main stress hormones, noradrenaline and adrenocorticotropic hormone (ACTH) were evaluated. ELF-EMF exposure did not alter body weight, and food and water intake. Plasma glucose level was increased and decreased in the groups which exposed to the 5 and 1Hz wave, respectively. Plasma ACTH concentration increased in both using frequencies, whereas noradrenaline concentration showed overall reduction. At last, numbers of rearing, sniffing, locomotor activity was increased in group receiving 5 Hz wave over the time. In conclusions, these data showed that the effects of 1 and 5 Hz on the hormonal, metabolic and stress-like behaviors may be different. Moreover, the influence of waves on stress system is depending on time of exposure.

Identification of morphine accumulation in the rat embryo central nervous system: a C14-morphine administration study

Previous studies have shown that morphine consumption during pregnancy may cause delay or defect of embryo development or abnormal nervous system function in the human and animal models. In the present study, the highest density of morphine accumulation in the central nervous system of rat embryos was evaluated using C14-morphine. Female Wistar rats [W 170-200 g] used and were crossed with male rats and coupling time was recorded [Embryonic day 0-E0]. Experimental groups received 0.05 mg/ml of C14-morphine in drinking water daily. On the 10[th] and 17[th] days of pregnancy, pregnant rats were anesthetized and the embryos with these uterus and placenta were surgically removed and were fixed in formalin 10% for 4 week. Then the embryos were processed, sectioned in 25 micro m and 5 micro m thicknesses, fixed on the glasses for further evaluations. The sectioned in 25, the glasses were fixed on the Blanc black and white film for 6 h. Then, the films were appeared and their negatives were prepared. The sectioned in five staining hematoxylin and eosin by light microscope and MOTIC software. Our results indicated that the highest C14-morphine accumulation was observed in the vesicles and the ventricular choroid plexus [CP] of [E17] embryos, whereas, in the [E10] embryos. Highest concentration was observed in the brain vesicles and the ventricular CP. In addition, this study showed the surface area of lateral, 3[rd] and 4[th] ventricular CP in the experimental groups were increased in compared to control groups. Our results indicated that effects of morphine on reduction of embryos brain development may be due to the highest accumulation of C14-morphine in the CP and brain vesicles

Oral morphine consumption reduces lens development in rat embryos

Consumption of morphine, during pregnancy, in addition to inducing defects in the mother's nervous system function, caused defects or delays in the formation and evolution of embryonic visual system. In the present study, changes in lens development were assessed in embryos exposed to morphine in utero. Female Wistar rats [250-300 g] were mated with male rats and pregnancy was determined by sperm observation in vaginal smear. This day was considered as embryonic day zero [E0]. The females were then divided randomly into the experimental and the control groups. The control group received tap water and the experimental group received morphine [0.05 mg/ml] in their water. On embryonic day 13 [E13], blood samples were collected from the retro-orbital sinus of all animals for plasma corticosterone detection. On embryonic day 17[E17], the animals were killed by an overdose of chloroform and the embryos were taken out surgically. The embryos were fixed in 10% formalin for 30 days. At this time, the head of the embryos were removed for tissue processing and Hematoxylin- Eosin [HandE] staining. The samples were evaluated using light microscope and MOTIC software. Our data indicated that plasma corticosterone level was dramatically increased and the lens was thinner in the experimental group. [Although the proliferation of lens cells increased in the experiment group but that lens had delay in removing the proliferated and elongation cells with abnormal density in the lateral part of the lens in comparison with the control group]. Moreover, the opening of the eyelids was delayed in the off springs of the mothers who received morphine. This study showed that morphine consumption during pregnancy leads to defects in fetal visual system development, particularly in the lens, and eyelids

Identification of site of morphine action in pregnant wistar rat placenta tissue: a C[14]-morphine study

In previous studies it has been emphasized that the site of morphine action may be either in the embryo or the placenta. In the present study, we attempt to identify the site of morphine action on the fetal section of Wistar rat placenta by using C14-morphine. In this study [experimental], female Wistar rats [weights: 170-200 g] were mated with male rats and their coupling times recorded. Experimental groups received daily doses of 0.05 mg/ml of C14-morphine in their drinking water. On the 9[th] and 14[th] embryonic days, the pregnant rats were anesthetized and the placenta and uterus surgically removed. Placentas were fixed in 10% formalin for two weeks, then processed, sectioned in 5 micro m and 25 micro m thicknesses, and fixed on glass slides for further evaluation. The 25 micro m sections were delivered to black and white film for three days. Films were processed and evaluated with a digital inverse microscope for possible radiological impression. The 5 micro m sections were processed for hematoxylin and eosin [H and E] staining, and evaluated by light microscope and MOTIC software. Our results indicated that the site of action of C14-morphine was possibly located on the blood plexus of the fetal portion of the placenta. In addition, oral morphine consumption was shown to inhibit fetal and maternal placental development in the experimental groups. We conclude that morphine's effectiveness on the reduction of embryo growth and development may be via its effects on the blood plexus of the fetal section of the placenta

Experiences Living with Fatigue in Iranian Veterans Chemically Injured by Sulfur Mustard Gas: A Phenomenological Study

PURPOSE: Fatigue affects the quality of life. Evidence shows that the phenomenon of fatigue is experienced differently depending on the type of disease and its consequences. The aim of the study was to explicate the meanings of the experience of living with fatigue in chemically injured veterans. METHODS: The hermeneutic phenomenology approach was used in this study, with an emphasis on Van Mennen's viewpoint and approach. According to Van Mennen, six overlapping dynamic activities are recommended to conduct a phenomenological study. During unstructured interviews, the participants were asked to describe their daily living experiences with fatigue. The participants were individuals who were chemically injured due to exposure to mustard gas. After examining every statement in the interview text, extractions of the meaning units, clustering, and themes were performed. RESULTS: The data explication was based on the third to sixth stages of Van Mennen's approach. The experience living with fatigue was classified into four essential themes: fatigue as a chronic condition, as an unstable and affected situation, as a physical condition of the entire individual, and as a mental condition of the entire individual. CONCLUSION: Due to unique social interactions and pathogenicity, victims of mustard gas experience fatigue differently than patients with other chronic diseases.

Reversal effect of intra-central henobar microinjection of L-arginine on place aversion induced by naloxone in morphine conditioned rats

Role of nitric oxide [NO] on expression of morphine conditioning using a solely classic task has been proposed previously. In this work, the involvement of NO on the expression of opioid-induced conditioning in the task paired with an injection of naloxone was investigated. Conditioning was established in adult male Wistar rats [weighing 200-250 g] using an unbiased procedure. Naloxone [0.05-0.4 mg/kg, i.p.], a selective antagonist of mu-opioid receptor, was administered once prior to morphine response testing. NO agents were administered directly into the central henobar [CeA] prior to naloxone injection pre-testing. Morphine [2.5-10 mg/kg, s.c.] produced a significant dose-dependent place preference in experimental animals. When naloxone [0.05-0.4 mg/kg, i.p.] was injected before testing of morphine [5 mg/kg, s.c.] response, the antagonist induced a significant aversion. This response was reversed due to injection of L-arginine [0.3-3 micro g/rat], intra-CeA prior to naloxone administration. However, pre-injection of L-NAME [intra-CeA], an inhibitor of NO production, blocked this effect. The finding may reflect that NO in the nucleus participates in morphine plus naloxone interaction

[Effect of oral morphine consumption during pregnancy on the tongue development in the Wistar rat embryos]

Morphine consumption during pregnancy could lead to defect and delay in nervous system development in the embryos. In the present study, development of the tongue of embryos whom their mothers received oral morphine during pregnancy have been studied. Female Wistar rats [200-220 g] after pregnancy were divided randomly into the experimental and control groups. The control group received tap water whereas the experimental group received morphine [0.05 mg/ml] in their drinking waters. On the day 19, the pregnant rats were killed by chloroform overdose and the embryos were removed surgically and were fixed in formalin 10%. Simultaneously, the rats' bloods were collected for corticosterone measurement. Weight and length of the embryos were determined. Then the embryos' heads were removed for tissue processing, cutting and Hematoxylin- Eosin staining. The subjects were evaluated using light microscope and MOTIC software. Number of the cells also counted. Un-paired t-test applied for statistical analysis. Plasma corticosterone level, embryos' weight and length did not show any significant differences between control and experimental groups. The large diameter of the tongue of the experimental group was decreased but the small diameter in two groups did not differ. Tongue cells numbers in the experimental group were increased but their size decreased. Decrease in the large diameter of tongue, increase in the cell number and decrease in cell size indicate the influence of morphine consumption during pregnancy on tongue development in the embryos

effect of morphine consumption on plasma corticosteron concentration and placenta development in pregnant rats

Previous studies have shown that morphine consumption during pregnancy may delay embryo development or cause abnormal nervous system function. The present study focused on the effect of maternal morphine consumption on development of placenta and blood corticosteron concentration in addictive pregnant mothers. 24 female rats, 170-200g weight, were used. The experimental groups after pregnancy received an oral dose of 0.05 mg/ml of morphine by tap water while the control group received only tap water. On 10[th] and 14[th] day of pregnancy, rats were anesthetized and placenta removed surgically, 1ml blood was collected from each pregnant mother from retro-orbital sinus, the concentration of blood corticosteron was determined by corticosteron Elisa kit after centrifugation. The fixed tissue was processed, sectioned and stained with hematoxylin and eosin. Placenta was studied microscopically according to the thickness of layers, area of blood cisterns, and the number of cells. Comparing the plasma corticosteron concentration of the treatment and the control groups, not only a severe increase in the treatment group was detected, but also the thickness of maternal and embryonic portions of the placenta at day 10th and 14th of gestation was different significantly [p

Effect of oral morphine consumption in female rats on development of brain cavities, central canal and choroid plexus of their embryos

Previous studies have shown that morphine consumption during pregnancy may delay embryo development or cause abnormal nervous system function. The present study focused on the effects of maternal morphine consumption on brain cavities and central canal development in Wistar rats. In this study Wistar rats [average weight: 170-200 g] were used. The experimental group, after pregnancy, received 0.05 mg/ml of morphine by tap water while the control group received water. On the 17[th] day of pregnancy, the pregnant animals were anesthetized by chloroform and embryos were surgically removed. The samples were fixed in 10% formalin for four weeks. Then, tissues were processed and sectioned. Sections were stained with hematoxylin and eosin [H and E] and examined for ventricle, central canal and choroid plexus development by light microscopy and MOTIC software. Severe reductions of the third and lateral ventricles were observed in the experimental group. In addition, an increase in the choroid plexus [CP] area in the experimental group with regards to the control group was identified. The study showed that oral morphine consumption lead to reduction in the third and lateral brain cavities and an increase in the CP area. This defect may cause behavioral changes observed in the F1 generation from addicted pregnant animals

Inhibition of cyclooxygenase type 1 and 2 enzyme by aqueous extract of elaegnus angustifolia in mice

Introduction: It has been shown that the extract of Elaeagnus angustifolia can inhibit inflammation and pain induced by formalin in mice and rats. The aim of the present study is to reach evaluations of possible cellular and molecular mechanisms of Elaeagnus angustifolia extract in reducing pain and inflammation through examining the extract ability for inhibition of cyclooxygenase [Cox] type 1 and 2 enzymes and corticosterone release from adrenal glands in mice. Methods: Male Swiss Webster mice were evaluated through the injection of 2 µliters to the plantar part of right foot. Elaeagnus angustifolia extract was injected to the animals 30 minutes before formalin. In order to evaluate the mechanism of extract, naloxone and memantine were administered intrapretonealy 30 minutes before the extract administration. In separate groups, after injection of extract, blood samples were taken from animals and corticosterone concentrations were measured. In an in vitro study the effect of extract on the activity of cyclooxygenase type 1 and 2 was assessed. Results: the research data showed the ineffectiveness of the extract on acute phase of pain induced by formalin but it completely inhibits the chronic phase. Naloxone and Memantine administration had no effect on the efficacy of extract in the chronic phase. Also the extract administration did not increase the plasma concentration of corticosterone in mice, but in vitro inhibited Cox1 and Cox 2 enzymes. Discussion: These results indicate that Elaeagnus angustifolia extract probably reducesww pain and inflammation caused by formalin in mice by inhibiting cyclooxygenase type 1 and 2 enzymes

Influence of nitric oxide in the central amygdala on the acquisition and expression of morphine-induced place preference in morphine sensitized rats

Effects of intra-central amygdala administration of L-arginine, a nitric oxide precursor, and NG-nitro-L-arginine methyl-ester [L NAME], a nitric oxide synthase inhibitor, on the morphine-induced sensitization and also on the expression of morphine-induced place conditioning in rats were studied. Subcutaneous [s.c.] administration of morphine [2.5, 5 and 7.5 mg/kg] induced place conditioning. Repeated pretreatment of morphine [5 mg/kg, i.p.] followed by 5 days no drug treatment, increased place conditioning induced by morphine [0.5 mg/kg]. Repeated intra-central amygdala administration of L-arginine [0.3, 1 and 3 µg/ rat], with morphine during acquisition of sensitization, significantly increased or reduced morphine place conditioning in sensitized rats. The drug administration before testing also increased and reduced the expression of morphine place conditioning in sensitized animals. Repeated intra-central amygdala injections of L-NAME [0.3, 1 and 3 µg/rat] with morphine during acquisition of sensitization, reduced the acquisition of morphine place conditioning in the sensitized animals. The drug injection before testing also reduced morphine induced conditioning. The results indicate that nitric oxide [NO] within the central amygdala may be involved in the acquisition and expression of morphine place conditioning in morphine-sensitized rats

Effects of oral morphine on the larvae, pupae and imago development in drosophila melanogaster

Previous studies, focusing on the effects of abused drugs, have used mice or rats as the main animal models; the present study tries to introduce a simple animal model. For this propose, we investigated the effects of oral morphine consumption by parents on the development of larvae, pupae and imago in Drosophila Melanogaster [D. Melanogaster]. In this experimental study, twenty male and 20 female D. Melanogaster pupae were housed in test tubes with banana [5 pupae /tube]. Male and female groups each were divided into three experimental group and one control group, which were maintained at 25 [degree sign] C. Morphine [0.2, 0.02, 0.002 mg/ml] was added into the test tubes of the experimental groups. The control group maintained at morphine-free test tube. The male and female groups with the same treatment were coupled and then female fertilization, egg deposit, larval, pupae and imago stages were studied macro and microscopically. The SPSS software [version 9.01] was used for statistical evaluations. In the experimental groups, in the larvae stage, both increase and decrease of length and surface area in the pupae stage were observed. The number of larvae pupae, and imago was reduced in the experimental groups. The study showed that oral morphine consumption by parents may affect the development of larvae, pupation and imago stages in D. Melanogaster. The results also showed that D. Melanogaster may be a reliable animal model to study on the concerns about abused drugs especially those with opioids