Enhanced Novel Object Recognition and Spatial Memory in Rats Selectively Bred for High Nicotine Preference.

This study examined the influence of genetic background on cognitive performance in a selectively bred high nicotine-preferring (NP) rat line. Using the novel object recognition (NOR), novel location recognition (NLR), and Morris water maze (MWM) tests, we evaluated object memory, spatial memory, and spatial navigation in nicotine-naive NP rats compared to controls. Our results demonstrate that in the NOR test, both male and female NP rats spent more time exploring the novel object (higher discrimination index) compared to sex-matched controls.

Chronic Nicotine Consumption and Withdrawal Regulate Melanocortin Receptor, CRF, and CRF Receptor mRNA Levels in the Rat Brain.

Alterations in the various neuropeptide systems in the mesocorticolimbic circuitry have been implicated in negative effects associated with drug withdrawal. The corticotropin-releasing factor (CRF) and α-melanocyte-stimulating hormone are two peptides that may be involved. This study investigated the regulatory effects of chronic nicotine exposure and withdrawal on the mRNA levels of melanocortin receptors (MC3R, MC4R), CRF, and CRF receptors (CRFR1 and CRFR2) expressed in the mesocorticolimbic system.

Decreased anxiety-like behavior in a selectively bred high nicotine-preferring rat line.

Genetic vulnerability contributes significantly to the individual variability observed in nicotine dependence. Selective breeding for sensitivity to a particular effect of abused drugs has produced rodent lines useful for studying genetic vulnerability to drug addiction. Previous research showed that anxiety-related personality traits are associated with nicotine dependence.

Chronic oral nicotine administration and withdrawal regulate the expression of neuropeptide Y and its receptors in the mesocorticolimbic system.

Neuropeptide Y (NPY) and its receptors are involved in the regulation of mood, stress, and anxiety. In parallel, NPY signaling may play a vital role in the negative affective state induced by drug withdrawal. This study examined the changes in the transcript levels of NPY, Y1, Y2, and Y5 receptors in the mesocorticolimbic system during chronic nicotine exposure and withdrawal.

Chronic nicotine-induced changes in gene expression of delta and kappa-opioid receptors and their endogenous ligands in the mesocorticolimbic system of the rat.

Delta and kappa opioid receptors (DOR and KOR, respectively) and their endogenous ligands, proenkephalin (PENK) and prodynorphin (PDYN)-derived opioid peptides are proposed as important mediators of nicotine reward. This study investigated the regulatory effect of chronic nicotine treatment on the gene expression of DOR, KOR, PENK and PDYN in the mesocorticolimbic system. Three groups of rats were injected subcutaneously with nicotine at doses of 0.

Gene expression of pro-opiomelanocortin and melanocortin receptors is regulated in the hypothalamus and mesocorticolimbic system following nicotine administration.

Pro-opiomelanocortin (POMC)-derived peptides and their receptors have been shown to play important roles in natural and drug-induced reward and reinforcement. Reward process may involve the regulation of POMC gene expression and the gene expression of POMC-derived peptide receptors. The present study investigated the alterations observed in the transcript levels of POMC, melanocortin 3 (MC3R), melanocortin 4 (MC4R) and mu-opioid receptors (MOR) in the hypothalamus and mesocorticolimbic system during nicotine exposure.

The protective effect of resveratrol against dentin bonding agents-induced cytotoxicity.

This study was designed to evaluate the cytotoxicity of four dentin bonding agents and the effects of an antioxidant addition. Group A: G-aenial Bond, Group B: Optibond All in One, Group C: Gluma Self Etch and Group D: Clearfil S(3) Bond were added to the medium using extract method. The cells were cultured with or without resveratrol (RES) addition.

Tideglusib protects neural stem cells against NMDA receptor overactivation.

Background: N-methyl-d-aspartate (NMDA) receptors are major pharmacological targets to prevent or reduce the progression of neurodegenerative diseases. Successful therapy with NMDA receptor antagonists in humans has been limited by the severe side effects of complete receptor blockade. The aim of the present study was to investigate the possible protective effects of tideglusib against NMDA receptor overactivation in neural stem cells.

Brain nitric oxide metabolites in rats preselected for nicotine preference and intake.

Nicotine addiction is a serious health problem resulting in millions of preventable deaths worldwide. The gas messenger molecule nitric oxide (NO) plays a critical role in addiction, and nicotine increases nitric oxide metabolites (NOx) in the brain. Understanding the factors which underlie individual differences in nicotine preference and intake is important for developing effective therapeutic strategies for smoking cessation.

Region- and sex-specific changes in CART mRNA in rat hypothalamic nuclei induced by forced swim stress.

Cocaine and amphetamine regulated transcript (CART) mRNA and peptides are highly expressed in the paraventricular (PVN), dorsomedial (DMH) and arcuate (ARC) nuclei of the hypothalamus. It has been suggested that these nuclei regulate the hypothalamic-pituitary-adrenal (HPA) axis, autonomic nervous system activity, and feeding behavior. Our previous studies showed that forced swim stress augmented CART peptide expression significantly in whole hypothalamus of male rats.

Efects of hormone replacement and tamoxifen on depression in ovariectomized rats.

Objectives: To determine the effects of tamoxifen and hormone replacement therapy in order to assess their role in depressive behavior:

Material And Methods: Different protocols of hormone replacement therapies were administered to surgically ovariectomized rats. Intact rats were used for tamoxifen experiments. Properly assigned control groups were used and cognitive processes were studied on animal models of surgical menopause using the Porsolt forced swim test and locomotor activity experiments.

The effect of hyperbaric oxygen on neuroregeneration following acute thoracic spinal cord injury.

Aims: Although hyperbaric oxygen (HBO) treatment following spinal cord injury (SCI) have been studied in terms of neurological function and tissue histology, there is a limited number studies on spinal cord tissue enzyme levels.

Main Methods: The effect of HBO treatment in SCI was investigated by measuring superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), nitric oxide synthase (NOS) and nitric oxide (NO) activity in the injured tissue. SCI was induced by applying an aneurysm clip extradurally at the level of T9-T11 vertebrae.

Forced swim stress elicits region-specific changes in CART expression in the stress axis and stress regulatory brain areas.

CART mRNA and peptides are highly expressed in the anatomical structures composing the hypothalamo-pituitary-adrenal (HPA) axis and sympatho-adrenal system. Anatomical and functional studies suggest that CART peptides may have a role in the regulation of the neuroendocrine and autonomic responses during stress. Our previous study showed that CART peptides increased significantly in the male hypothalamus and amygdala 10min after the forced swim stress.

NADPH-d and Fos reactivity in the rat spinal cord following experimental spinal cord injury and embryonic neural stem cell transplantation.

Aims: The aim of this study is to determine the role of nitric oxide (NO) in neuropathic pain and the effect of embryonic neural stem cell (ENSC) transplantation on NO content in rat spinal cord neurons following spinal cord injury (SCI).

Main Methods: Ninety adult male Sprague-Dawley rats were divided into 3 groups (n=30, each): control (laminectomy), SCI (hemisection at T12-T13 segments) and SCI+ENSC. Each group was further divided into sub-groups (n=5 each) based on the treatment substance (L-NAME, 75 mg/kg/i.

Hippocampal neuronal nitric oxide synthase (nNOS) is regulated by nicotine and stress in female but not in male rats.

NO (nitric oxide) produced in limbic brain regions has important roles in the regulation of autonomic nervous system and HPA axis activity, anxiety, fear learning, long-term memory formation, and depression. NO is synthesized from l-arginine in a reaction catalyzed by nitric oxide synthase (NOS). Neuronal nitric oxide synthase (nNOS), one of the three isoforms of NOS, is synthesized constitutively in nerve cells.

Effect of prolonged administration of bovine lactoferrin in neuropathic pain: involvement of opioid receptors, nitric oxide and TNF-alpha.

Aims: This study aimed to investigate the effect of prolonged administration of bovine milk lactoferrin (bLF) on hyperalgesia and allodynia in a rat model of neuropathic pain and to determine the involvement of c-Fos, TNF-alpha, nitric oxide and opioidergic systems in this effect.

Main Methods: Neuropathic pain was induced in rats by loose ligation of the right sciatic nerve and evaluated by tests measuring the mechanical and thermal hyperalgesia and allodynia. bLF (50, 100, and 200mg/kg) alone or in combination with opioidergic antagonists were administered intraperitoneally to the rats with neuropathic pain.

Nicotine-induced conditioned place preference in rats: sex differences and the role of mGluR5 receptors.

To elucidate sex differences in nicotine addiction and the underlying mechanisms of the conditioning aspects of nicotine, nicotine-induced conditioned place preference (CPP) was evaluated in male and female Sprague Dawley rats using a three-chambered CPP apparatus and a biased design. In a series of experiments, the dose-response curve was obtained, pairings between the drug and initially non-preferred versus preferred compartments were compared, and the involvement of mGluR5 receptors in nicotine-induced CPP was evaluated. Modulation of nicotine-induced CPP with mGluR5 inhibition was obtained by MPEP (2-methyl-6-(phenylethynyl)-pyridine hydrochloride).