Optogenetic inhibition of the medial prefrontal cortex reduces methamphetamine-primed reinstatement in male and female rats
Preclinical findings suggest sex-differences exist in drug-seeking behavior following methamphetamine (METH) self-administration. The medial prefrontal cortex (mPFC), is thought to contribute to the reinstatement of drug-seeking in males. Glutamatergic neurons project from the prelimbic portion of the mPFC to various brain regions modulating activity including the nucleus accumbens; thus the prelimbic region of the mPFC is thought to contribute to drug-seeking behaviors. Although studied in males, little research has investigated the role of the mPFC in females. The purpose of this study was to investigate if the prelimbic...
Source: Behavioural Pharmacology - August 6, 2019 Category: Drugs & Pharmacology Tags: Research Reports Source Type: research
Effects of N-ethylpentylone on locomotor activity and anxiety-like behavior in rats
In this study, locomotor stimulation and sensitization, as well as anxiety-like behavior induced by NEP were studied in Sprague-Dawley rats, using the open field and elevated plus maze respectively. Rats were administered NEP (5, 20 or 50 mg/kg, intraperitoneal), with saline as the negative control and methamphetamine (5 mg/kg) as a positive control. Acute administration of NEP at all the doses tested significantly promoted locomotor activity, presenting an inverted U-shaped dose-effect curve. The highest activity was observed at the 20 mg/kg dose group, with the average distance traveled 18 times higher than the saline gr...
Source: Behavioural Pharmacology - August 6, 2019 Category: Drugs & Pharmacology Tags: Research Reports Source Type: research
Changes in behavioral and neuronal parameters by alcohol, cigarette, or their combined use in rats
Few studies have explored the effects of the combined use of alcohol and cigarette in humans, despite its prevalence. Here we evaluated the effect of isolated and combined use on behaviors and neuronal parameters in rats. Male adult rats were divided into alcohol (AL, 2 g/kg, by oral gavage), cigarette smoke (TB, six cigarettes, by inhalation), combined use (ALTB), or control (CT, water by oral gavage and environmental air) groups, treated twice a day (09.00 and 14.00 h). After 4 weeks, the rats were tested in the open field for behavioral analysis and euthanized for brain volume estimation and counting of neurons in the h...
Source: Behavioural Pharmacology - August 6, 2019 Category: Drugs & Pharmacology Tags: Research Reports Source Type: research
The muscarinic agonist pilocarpine modifies cocaine-reinforced and food-reinforced responding in rats: comparison with the cholinesterase inhibitor tacrine
This study evaluated its effects on cocaine-reinforced and food-reinforced behaviors in rats, using the cholinesterase inhibitor tacrine as a comparator. Intraperitoneal pilocarpine or tacrine at doses of 1.0 mg/kg or more attenuated self-administration of low-dose cocaine (0.1 mg/kg injection) but also increased oral movements. Pilocarpine was less potent than tacrine in decreasing responding supported by low or intermediate amounts of liquid food. Combined treatment with pilocarpine and tacrine was more effective than either compound alone in attenuating self-administration of intermediate-dose cocaine. At a low (0.66 mg...
Source: Behavioural Pharmacology - August 6, 2019 Category: Drugs & Pharmacology Tags: Research Reports Source Type: research
Role of AMPA receptor stimulation and TrkB signaling in the antidepressant-like effect of ketamine co-administered with a group II mGlu receptor antagonist, LY341495, in the forced swim test in rats
Ketamine has been shown to induce a rapid antidepressant effect on patients with depression. In many animal models, both rapid and sustained antidepressant activities were also found in response to an antagonist of group II metabotropic glutamate receptors, LY341495, and its mechanism of action seemed to be similar in many ways to the action of ketamine. It has also been found that LY341495 enhanced the antidepressant-like activity of sub-effective doses of ketamine in rats without inducing adverse effects. Here, we investigated the role of AMPA receptor and TrkB receptor activation in the antidepressant-like effects of ke...
Source: Behavioural Pharmacology - August 6, 2019 Category: Drugs & Pharmacology Tags: Research Reports Source Type: research
Effects of monoamine uptake inhibitors on pain-related depression of nesting in mice
Pain is a significant public health problem, and assessment of pain-related impairment of behavior is a key clinical indicator and treatment target. Similar to opioids and NSAIDs, dopamine (DA) transporter inhibitors block pain-related depression of intracranial self-stimulation (ICSS) in rats. The primary goal of the present study was to determine if the effects of monoamine uptake inhibitors on pain-related depression of ICSS in rats extend to an assay of pain-related depression of nesting in mice. We hypothesized that the DA transporter-selective uptake inhibitor bupropion would block depression of nesting behavior prod...
Source: Behavioural Pharmacology - August 6, 2019 Category: Drugs & Pharmacology Tags: Research Reports Source Type: research
Effects of the α2/α3-subtype-selective GABAA receptor positive allosteric modulator KRM-II-81 on pain-depressed behavior in rats: comparison with ketorolac and diazepam
This study examined effects of the α2/α3-subtype-selective GABAA receptor positive allosteric modulator KRM-II-81 in an assay of pain-related behavioral depression. Adult, male Sprague-Dawley rats responded for electrical brain stimulation in a frequency-rate intracranial self-stimulation (ICSS) procedure. Intraperitoneal injection of 1.8% lactic acid served as an acute noxious stimulus to depress ICSS. Effects of KRM-II-81 were evaluated in the absence and presence of the acid noxious stimulus. The NSAID ketorolac and the benzodiazepine diazepam were tested as comparators. Neither ketorolac nor KRM-II-81 altered ICSS in...
Source: Behavioural Pharmacology - July 5, 2019 Category: Drugs & Pharmacology Tags: RESEARCH REPORTS Source Type: research
Alterations of acoustic features of 50 kHz vocalizations by nicotine and phencyclidine in rats
Ultrasonic vocalizations are widely used to examine affective states in rats, yet relatively few studies explore the acoustic features of vocalizations, especially in relation to drug exposure, and no studies have explored alterations in acoustic features over time. The goal of this study was to examine nicotine- and phencyclidine-induced alterations of bandwidth, duration, and frequency of 50 kHz vocalizations. The minimum and maximum frequency, bandwidth, and duration of calls were examined after 7 days of daily subcutaneous administration of phencyclidine (2.0 mg/kg) and nicotine (0.2 and 0.4 mg/kg) in male Sprague-Dawl...
Source: Behavioural Pharmacology - July 5, 2019 Category: Drugs & Pharmacology Tags: RESEARCH REPORTS Source Type: research
Parental morphine exposure enhances morphine (but not methamphetamine) preference and increases monoamine oxidase-B level in the nucleus accumbens
Opioid addiction is one of the most crucial issues in the world. Opioid abuse by parents makes children more prone to many psychological disorders such as drug addiction. Therefore, this study was carried out to examine the effect of morphine exposure 10 days before gestation on morphine and methamphetamine preference in male offspring. Adult Wistar rats (male and female) received morphine orally for 21 days and were drug free for 10 days. Thereafter, they were allowed to mate with either a morphine-abstinent or drug-naive rat. The male offspring were tested for morphine and methamphetamine preference with a three-bottle c...
Source: Behavioural Pharmacology - July 5, 2019 Category: Drugs & Pharmacology Tags: RESEARCH REPORTS Source Type: research
Effects of imidazoline I2 receptor agonists on reserpine-induced hyperalgesia and depressive-like behavior in rats
This study examined the antinociceptive and antidepressant-like effects of imidazoline I2 receptor (I2R) agonists in a reserpine-induced model of fibromyalgia in rats. Rats were treated for 3 days with vehicle or reserpine. The von Frey filament test was used to assess the antinociceptive effects of I2 receptor agonists, and the forced swim test was used to assess the antidepressant-like effects of these drugs. 2-BFI (3.2–10 mg/kg, intraperitoneally), phenyzoline (17.8–56 mg/kg, intraperitoneally), and CR4056 (3.2–10 mg/kg, intraperitoneally) all dose-dependently produced significant antinociceptive effects, wh...
Source: Behavioural Pharmacology - July 5, 2019 Category: Drugs & Pharmacology Tags: RESEARCH REPORTS Source Type: research
Further pharmacological comparison of D-methamphetamine and L-methamphetamine in rats: abuse-related behavioral and physiological indices
This study examined potential abuse-related and adverse physiological effects of D -MA and L -MA alone and in combination in rats, as these effects had not been previously characterized. Potential abuse-related effects were examined in locomotor sensitization and conditioned place preference paradigms. Body temperature was monitored to assess the physiological effects of these drugs or drug combinations. In the locomotor study, D-MA induced locomotor sensitization to both D-MA and L -MA. L -MA induced locomotor sensitization only to D-MA. Responses to a combination of L-MA and D -MA were not differentially affected by L-MA...
Source: Behavioural Pharmacology - July 5, 2019 Category: Drugs & Pharmacology Tags: RESEARCH REPORTS Source Type: research
Differential cross-tolerance to the effects of nicotinic acetylcholine receptor drugs in C57BL/6J mice following chronic varenicline
This study examined the consequences of daily varenicline treatment on disruptions in operant responding (i.e. rate-decreasing effects) and hypothermia induced by administration of nicotine, epibatidine, cytisine, and cocaine in C57BL/6J mice. Furthermore, mecamylamine was used to assess the involvement of nAChRs in the effects of varenicline. Mice were trained under a fixed ratio 20 of milk reinforcement, and rectal temperatures were measured after 30 min following drug-administration. Varenicline, nicotine, epibatidine, and cytisine produced dose-dependent decreases in response rate and rectal temperature. Chronic vare...
Source: Behavioural Pharmacology - July 5, 2019 Category: Drugs & Pharmacology Tags: RESEARCH REPORTS Source Type: research
Normal extinction and reinstatement of morphine-induced conditioned place preference in the GluA1-KO mouse line
Extinction and reinstatement of morphine-induced conditioned place preference were studied in glutamate α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-receptor GluA1 subunit-deficient mice (global GluA1-KO mice). In line with previous findings, both acquisition and expression of conditioned place preference to morphine (20 mg/kg, subcutaneously) were fully functional in GluA1 KO mice compared with wild-type littermate controls (GluA1-WT), thus enabling the study of extinction. With a 10-session extinction paradigm, the GluA1 KO mice showed complete extinction similar to that of the GluA1-WT mice. Morphine-induced ...
Source: Behavioural Pharmacology - July 5, 2019 Category: Drugs & Pharmacology Tags: RESEARCH REPORTS Source Type: research
Sexual behaviour of the female rat during late adolescence: effect of chronic cocaine treatment
Sexual behaviour is highly motivated and female rats begin to express it during adolescence. The circuitries implicated in the control of motivated behaviours continue to mature during adolescence and seem more sensitive to the effects of psychostimulants such as cocaine. However, a putative differential effect of this drug on the sexual behaviour of females according to age has not yet been studied. Therefore, we compared the motivational value of a male and the expression of sexual behaviour of late-adolescent and adult female rats after chronic treatment with a vehicle or 15.0 mg/kg cocaine. The strong incentive value...
Source: Behavioural Pharmacology - July 5, 2019 Category: Drugs & Pharmacology Tags: RESEARCH REPORTS Source Type: research
Functional and molecular changes in the nucleus accumbens of MK-801-sensitized rats
Behavioural sensitization is a putative mechanism in the pathophysiology of drug addiction and neuropsychiatric disorders such as schizophrenia. In rodents, drug-induced behavioural sensitization has been described for several different drug classes. The N-methyl-D-aspartate receptor antagonist MK-801 can inhibit sensitization to other drugs of abuse. However, MK-801 also produces behavioural sensitization to its own hyperlocomotor inducing effects, suggesting that MK-801 sensitization has a distinctive mechanism of action. The aim of this study was to carry out a functional and molecular analysis of the nucleus accumbens ...
Source: Behavioural Pharmacology - July 5, 2019 Category: Drugs & Pharmacology Tags: RESEARCH REPORTS Source Type: research
