Tropisetron enhances recognition memory in ovariectomized female rats
The present study evaluated the acute effects of the 5-HT3 receptor antagonist, tropisetron, on recognition memory in ovariectomized adult female rats. The non-spatial novel object recognition task was used to assess recognition memory. In this task, ovariectomized rats explored two identical objects during Trial 1. Immediately after Trial 1, rats were primed either with oil, 250 µg progesterone, 20 µg of estrogen, or 20 µg of estrogen + 250 µg progesterone. Four hours later, the test trial (Trial 2) was initiated. Thirty minutes before Trial 2, rats were injected intraperitoneally with either saline, 1.5 or 2.5 mg/Kg ...
Source: Behavioural Pharmacology - November 13, 2020 Category: Drugs & Pharmacology Tags: Short Reports Source Type: research
Re-evaluation of the discriminative stimulus effects of lysergic acid diethylamide with male and female Sprague-Dawley rats
Recent discoveries from clinical trials with psychedelic-assisted therapy have led to a resurgence of interest in the psychopharmacology of lysergic acid diethylamide (LSD). Preclinical drug discrimination is an invaluable tool to investigate the neurochemical mechanisms underlying subjective drug effects. The current study extends previous drug discrimination research by including both sexes. Adult female (n = 8) and male (n = 8) Sprague-Dawley rats were trained to discriminate 0.08 mg/kg LSD from saline under a fixed ratio 20 schedule of food reinforcement. Substitution tests were conducted with several substan...
Source: Behavioural Pharmacology - November 13, 2020 Category: Drugs & Pharmacology Tags: Research Reports Source Type: research
Pharmacological depletion of serotonin and norepinephrine with para-chlorophenylalanine and alpha-methyl-p-tyrosine reverses the antidepressant-like effects of adolescent caffeine exposure in the male rat
Adolescent exposure to caffeine has been shown to decrease immobility in the forced swim test, suggesting and antidepressant-like effect of caffeine; however, studies have produced different results with regard to caffeine-induced active behaviors. The present study attempted to clarify the possible neurochemical mechanisms of caffeine’s action by selectively depleting norepinephrine with alpha-methyl-p-tyrosine or serotonin with para-chlorophenylalanine in two separate experiments and assessing the ability for caffeine to alter anxiety-like and depressive-like behavior. Caffeine-treated adolescent male rats were exposed...
Source: Behavioural Pharmacology - November 13, 2020 Category: Drugs & Pharmacology Tags: Research Reports Source Type: research
The orexin receptors in the ventral tegmental area are involved in the development of sensitization to expression of morphine-induced preference in rats
Recent studies have shown that orexin neurons in the lateral hypothalamus send a compelling project to the ventral tegmental area (VTA). Besides, orexin-1 (OX1) and orexin-2 (OX2) in the VTA are necessary for the development of morphine-induced place preference. Also, sensitivity to morphine can reinforce the rewarding effects of morphine. The current study aims to determine the role of VTAs orexin receptors in morphine sensitization in rats. In 84 adult male albino Wistar rats, two separate cannulae bilaterally implanted into the VTA. They received intra-VTA infusions of SB334867 (0.1, 1 and 10 nM) and TCS OX2 29 (1, 7 ...
Source: Behavioural Pharmacology - November 13, 2020 Category: Drugs & Pharmacology Tags: Research Reports Source Type: research
Effects of the GluN2B antagonist, Ro 25-6981, on extinction consolidation following adolescent- or adult-onset methamphetamine self-administration in male and female rats
Previous work suggests adolescent rats have deficient extinction consolidation relative to adults. Although the mechanisms underlying this age difference are currently unknown, studies in adult rats have implicated GluN2B-containing N-methyl-d-aspartate (NMDA) receptor function in extinction consolidation of drug-associated memory. Importantly, GluN2B neurotransmission emerges during adolescent development, and drugs of abuse during adolescence may delay the development of extinction consolidation by disrupting the ontogeny of GluN2B function. Here, we trained Sprague–Dawley rats of both sexes to self-administer methamph...
Source: Behavioural Pharmacology - November 13, 2020 Category: Drugs & Pharmacology Tags: Research Reports Source Type: research
The aroylhydrazone INHHQ prevents memory impairment induced by Alzheimer’s-linked amyloid-β oligomers in mice
Converging evidence indicates that neurotoxicity and memory impairment in Alzheimer’s disease is induced by brain accumulation of soluble amyloid-β oligomers (AβOs). Physiological metals are poorly distributed and concentrated in the senile plaques typical of Alzheimer’s disease, where they may be coordinated to the amyloid-β peptide (Aβ). Indeed, zinc and copper increase Aβ oligomerization and toxicity. Metal-protein attenuating compounds represent a class of agents proposed for Alzheimer’s disease treatment, as they reduce abnormal interactions of metal ions with Aβ, inhibit Aβ oligomerization and prevent de...
Source: Behavioural Pharmacology - November 13, 2020 Category: Drugs & Pharmacology Tags: Research Reports Source Type: research
The antinociceptive mechanisms of melatonin: role of l-arginine/nitric oxide/cyclic GMP/KATP channel signaling pathway
In conclusion, the antinociceptive effect of melatonin is mediated through the l-arginine/NO/cGMP/KATP pathway. (Source: Behavioural Pharmacology)
Source: Behavioural Pharmacology - November 13, 2020 Category: Drugs & Pharmacology Tags: Research Reports Source Type: research
Anti-inflammatory and anti-hypersensitive effects of the chalcone isocordoin and its semisynthetic derivatives in mice
This study aimed to evaluate the anti-hypersensitive and anti-inflammatory effects of isocordoin (1) and several natural and semisynthetic derivatives (2–10). Initial evaluation of (1), dihydroisocordoin (2) and six semisynthetic derivatives (3–8) in the inhibition of abdominal writhes induced by acetic acid model showed that only isocordoin dimethylether (5) caused more than 70% of inhibition. Further evaluation of 5 for its anti-oedematogenic activity and anti-hypersensitivity effect induced by carrageenan, lipopolysaccharide (LPS), bradykinin (BK), prostaglandin E2 (PGE2), and epinephrine showed that isocordoin dime...
Source: Behavioural Pharmacology - November 13, 2020 Category: Drugs & Pharmacology Tags: Research Reports Source Type: research
Pain impairs consolidation, but not acquisition or retrieval of a declarative memory
In this study, we asked whether pain affects memory acquisition, consolidation and retrieval as well as whether memory impairment depends on pain intensity. Wistar rats received a hind paw injection of formalin (1%) at different phases of object recognition test. The injection of formalin after training but not before training or testing impaired object recognition memory. We concluded that pain impairs the consolidation but not acquisition or retrieval of object recognition memory, which is a subtype of declarative memory. Morphine, at a dose that did not affect object recognition memory in control rats, drastically reduc...
Source: Behavioural Pharmacology - November 13, 2020 Category: Drugs & Pharmacology Tags: Research Reports Source Type: research
Crossover associations of alcohol and smoking, craving and biochemically verified alcohol and nicotine use in heavy drinking smokers
This study examined associations between drinking and smoking prior to treatment (biochemically measured at baseline), alcohol and tobacco craving, and biochemical alcohol and tobacco use during the analog trial period. We conducted a secondary data analysis of a randomized clinical analog trial where participants with a Diagnostic and Statistical Manual, Fourth Edition Text Revision (DSM-IV-TR) diagnosis of alcohol dependence, abuse or reported heavy drinking, with a co-occurring DSM-IV-TR diagnosis of nicotine dependence, abuse or reported heavy use, who were not seeking treatment were recruited. A generalized estimation...
Source: Behavioural Pharmacology - September 11, 2020 Category: Drugs & Pharmacology Tags: Short Report Source Type: research
Partial and full deletion of nicotinic acetylcholine receptor α4 and β2 subunits reduces sensitivity to acute nicotine administration and development of tolerance following chronic nicotine administration
The diversity of nicotinic cholinergic receptor (nAChR) subunits underlies the complex responses to nicotine. Mice differing in the expression of α4 and β2 subunits, which are most widely expressed in brain, were evaluated for the responses to acute nicotine administration on Y-maze crossings and rears, open-field locomotion and body temperature following chronic treatment with nicotine (0, 0.25, 1.0 and 4.0 mg/kg/h). Deletion or partial deletion of the α4, β2 or both nAChR subunits reduced the sensitivity of mice to acute nicotine administration. This reduced sensitivity was gene dose-dependent. Modification of α4 ...
Source: Behavioural Pharmacology - September 11, 2020 Category: Drugs & Pharmacology Tags: Research Reports Source Type: research
Roflumilast attenuates cognitive deficits in estrogen insufficient rats
Estrogen replacement therapy including specific estrogen receptor alpha (ERα) agonist, 4,4′,4″-(4-propyl-[1H] pyrazole-1,3,5-triyl) trisphenol (PPT), improves cognitive function in the females with estrogen insufficiency condition. It is well suggested that the cyclic nucleotides are considered as one of the downstream mediators to ERα receptor activity and they can be hypothesized as a potential target in the management of estrogen insufficiency condition. Roflumilast, a phosphodiesterase-4 inhibitor, increases the level of cyclic adenosine monophosphate (cAMP) in most of the tissues including the brain, and is repo...
Source: Behavioural Pharmacology - September 11, 2020 Category: Drugs & Pharmacology Tags: Research Reports Source Type: research
Sequential habituation to space, object and stranger is differentially modulated by glutamatergic, cholinergic and dopaminergic transmission
Novel object and social interaction tasks allow assessments of rodent cognition and social behavior. Here, we combined these tasks and defined unequivocal locations of interest. Our procedure, termed OF-NO-SI, comprised habituation to the open field (OF), novel object (NO) and social interaction (SI) stages. Habituation was measured within- and between-trials (10 minutes each, two per stage). Ambulation emerged as the appropriate proxy during the OF stage, but NO and SI trials were best quantified via direct exploration measures. We pharmacologically validated the paradigm using 5-month old C57BL/6J male mice, treated intr...
Source: Behavioural Pharmacology - September 11, 2020 Category: Drugs & Pharmacology Tags: Research Reports Source Type: research
Effects of treadmill exercise and sex hormones on learning, memory and hippocampal brain-derived neurotrophic factor levels in transient congenital hypothyroid rats
Transient thyroid function abnormalities at birth exhibit intellectual developmental and cognitive disorders in adulthood. Given the well-known effects of physical activity and sex hormones on cognitive functions and brain-derived neurotrophic factor (BDNF), the present study examined the effects of treadmill exercise, sex hormones, and the combined treatment on learning and memory and hippocampal BDNF levels in transient congenital hypothyroid rats. To induce hypothyroidism, 6-propyl-2-thiouracil was added to the drinking water from the 6th day of gestation to the 21st postnatal day (PND). From PNDs 28 to 47, female and m...
Source: Behavioural Pharmacology - September 11, 2020 Category: Drugs & Pharmacology Tags: Research Reports Source Type: research
Repeated ketamine administration induces recognition memory impairment together with morphological changes in neurons from ventromedial prefrontal cortex, dorsal striatum, and hippocampus
Ketamine is an anesthetic agent that antagonizes N-methyl-d-aspartate receptors, inducing psychotic-like symptoms in healthy humans and animals. This agent has been used as a pharmacological tool for studying biochemical and physiological mechanisms underlying the clinical manifestations of schizophrenia. The main goal of this study was to evaluate the effect of repeated injections of ketamine (5 and 10 mg/kg, i.p., daily for 5 days) on recognition memory and neuronal morphology in ICR-CD1 mice. This treatment induced recognition memory impairment in the novel object recognition test and a decrease in dendritic spines dens...
Source: Behavioural Pharmacology - September 11, 2020 Category: Drugs & Pharmacology Tags: Research Reports Source Type: research
