Effects of electrical stimulation of dorsal raphe nucleus on neuronal response properties of barrel cortex layer IV neurons following long-term sensory deprivation

Abstract: Objective To evaluate the effect of electrical stimulation of dorsal raphe nucleus (DRN) on response properties of layer IV barrel cortex neurons following long-term sensory deprivation. Methods: Male Wistar rats were divided into sensory-deprived (SD) and control (unplucked) groups. In SD group, all vibrissae except the D2 vibrissa were plucked on postnatal day one, and kept plucked for a period of 60 d. After that, whisker regrowth was allowed for 8-10 d. The D2 principal whisker (PW) and the D1 adjacent whisker (AW) were either deflected singly or both deflected in a serial order that the AW was deflected 20 ms before PW deflection for assessing lateral inhibition, and neuronal responses were recorded from layer IV of the D2 barrel cortex. DRN was electrically stimulated at inter-stimulus intervals (ISIs) ranging from 0 to 800 ms before whisker deflection. Results: PW-evoked responses increased in the SD group with DRN electrical stimulation at ISIs of 50 ms and 100 ms, whereas AW-evoked responses increased at ISI of 800 ms in both groups. Whisker plucking before DRN stimulation could enhance the responsiveness of barrel cortex neurons to PW deflection and decrease the responsiveness to AW deflection. DRN electrical stimulation significantly reduced this difference only in PW-evoked responses between groups. Besides, no DRN stimulation-related changes in response latency were observed following PW or AW deflection in either group. Moreover, condition test (CT) ratio increased in SD rats, while DRN stimulation did not affect the CT ratio in either group. There was no obvious change in 5-HT2A receptor protein density in barrel cortex between SD and control groups. Conclusion: These results suggest that DRN electrical stimulation can modulate information processing in the SD barrel cortex

Dose-Dependent Effect of GABAA System on Antinociception Actions of Cuneiformis Nucleus in Brain Stem

Background & Objective: It's been considered that midbrain region namely rostral ventromedial medulla (RVM) is the coring point of modulation of pain. The periaqueductal gray (PAG) matter has been documented to act as antinociceptive along with RVM. However, there are evidences demonstrating that RVM get a few connections from the cuneiformsnucleus (CnF) which might indicate CnF does have the same mechanism as PAG. Thus in this study, we tried to explore the antinociception effects of CnF and GABAA circuits.  Methods: Rats were anesthetized with Thiopental drug. Using the stereotaxic apparatus and Paxinos atlas, the point representing for CnF location over the scalp has been designated. One week after the surgery, rats were fully prepared for tests. Animals were put in three groups. First for control group, 0.5 µl of normal saline was injected into the CnF. Later, a few nanograms of bicucculline (as a GABAA antagonist) were administered into the CnF, dose dependently.  Results: From the results, it has been shown that CnF has a role in antinociception effect since the injection of bicucculline increased tail flick latency (TFL) and even further increased TFL when administered dose dependently (with high doses). Conclusion: According to results of current study, CnF has a significant role in pain modulation and circuits of GABAergic system also plays a key role on its antinociception effect

The Effect of Hydroalcoholic Extract of Truffle on Estrogen and Progesterone Levels in Experimental Model of Multiple Sclerosis (MS) in Female Rats

Abstract Background: The multiple sclerosis is a chronic disease of the central nervous system. Since the level of sex hormone and multiple sclerosis (MS) disease affects one another, the aim of this study was to evaluate the impact of the hydroalcoholic extract of truffle on the hormone levels of estrogen and progesterone administered in experimental model of MS-induced rats. Materials and Methods: In this experimental study, 42 Wistar female rats, weighing 180±10 grams selected into 6 groups each consisting of 7 rats. Normal control didn’t receive any treatment and experimental group was given Cuprizone toxin (as a MS model inducer) for 40 days. The experimental groups (2, 3, 4 and 5) in addition to Cuprizone received the normal saline, 110, 220 and 330 mg/kg/0.2ml (i.p.) of Hydroalcoholic extract of truffle for 12 days too. Blood samples were taken at the end of the twelfth day from all groups involved and levels of sex hormones were measured. Results: Cuprizone decreases estrogen, progesterone levels and also causes weight loss, while injection of hydroalcoholic extract of truffle increased serum levels of estrogen (in experimental group 4) and progesterone (in experimental group 4 & 5) compared to MS-induced group. Conclusion: Results of the study revealed that the hydroalcoholic extract of truffle (at dosages of 220 and 330 mg/kg) could increase estrogen and progesterone levels in rats experienced experimental multiple sclerosis

Effect of Hydroalcoholic Extracts of Truffle (Terfezia boudieri) Premedication on Improving Hepatic Factors in CCl4-induced Liver Injury in Male Rats

Background & objectives: Terfezia boudieri (TB) has more than 15 types of proteins, gallic acid, catechins, flavonoids, tannins and other compounds such as beta-carotene and linoleic acid. Some of these compounds have antioxidant and anti-hyperlipidemia effects. Therefore, this study aimed to examine the antioxidant and protective effects of this fungus on the liver injury induced by carbon tetrachloride. Methods: 30 male Wistar rats were divided randomly into 5 groups (each group containing 6). Group 1 (normal control group) and group 2 (control CCl4) were given normal saline for 14 days. Group 3, 4 and 5 received 500, 1000 and 1500 mg/ kg doses of methanol extract of TB for 14 days, respectively before the injection of carbon tetrachloride. In the fourteenth day, all groups except group 1 were given 1.5 ml/kg of carbon tetrachloride (V / V 1: 1 dissolved in olive oil). Group 1, instead of carbon tetrachloride, received 1.5 ml/kg of olive oil on the fourteenth day. Results: Injection of carbon tetrachloride in rats increased serum activity of ALT, AST, ALP and serum degrees of triglycerides, VLDL, LDL, HDL, total cholesterol, glucose, and reduced HDL and total antioxidant capacity (TAC); while pre-treatment with methanol extract of TB significantly reversed the changes. Conclusion: The results of this study showed that methanol extract of TB can protect the liver against oxidants and free radicals produced by carbon tetrachloride metabolism