Operant self-administration of pregabalin in a mouse model of neuropathic pain.

Background: Pregabalin is a first-line agent for neuropathic pain treatment whose abuse liability remains controversial. Surprisingly, studies exploring the reinforcing properties of pregabalin in operant mouse models are missing.

Methods: We evaluated the acquisition of operant pregabalin self-administration in mice exposed to a partial sciatic nerve ligation (PSNL) or a sham operation.

Flavors paired with internal pain or with nausea elicit divergent types of hedonic responses.

Pairing a taste with either internal pain (e.g., from hypertonic saline injection) or nausea (e.

Alcohol seeking by rats becomes habitual after prolonged training.

Background: This study examines the effect of the amount of training on alcohol seeking behavior in rats. Contemporary theories of instrumental learning suggest that habit learning processes are involved in the development of the compulsive drug seeking that characterizes addiction.

Method: Wistar rats were trained to perform an instrumental response for a solution of ethanol.

Beware of your Cre-Ation: lacZ expression impairs neuronal integrity and hippocampus-dependent memory.

Expression of the lacZ-sequence is a widely used reporter-tool to assess the transgenic and/or transfection efficacy of a target gene in mice. Once activated, lacZ is permanently expressed. However, protein accumulation is one of the hallmarks of neurodegenerative diseases.

Role of the endocannabinoid system in the emotional manifestations of osteoarthritis pain.

In this study, we investigated the role of the endocannabinoid system (ECS) in the emotional and cognitive alterations associated with osteoarthritis pain. The monosodium iodoacetate model was used to evaluate the affective and cognitive manifestations of osteoarthritis pain in type 1 (CB1R) and type 2 (CB2R) cannabinoid receptor knockout and wild-type mice and the ability of CB1R (ACEA) and CB2R (JWH133) selective agonists to improve these manifestations during a 3-week time period. The levels of the endocannabinoids anandamide (AEA) and 2-arachidonoylglycerol (2-AG) were measured in plasma and brain areas involved in the control of these manifestations.

Involvement of the endocannabinoid system in osteoarthritis pain.

Osteoarthritis is a degenerative joint disease associated with articular cartilage degradation. The major clinical outcome of osteoarthritis is a complex pain state that includes both nociceptive and neuropathic mechanisms. Currently, the therapeutic approaches for osteoarthritis are limited as no drugs are available to control the disease progression and the analgesic treatment has restricted efficacy.

Sigma-1 receptor antagonism as opioid adjuvant strategy: enhancement of opioid antinociception without increasing adverse effects.

While opioids are potent analgesics widely used in the management of pain, a number of well-known adverse effects limit their use. The sigma-1 receptor is a ligand-regulated molecular chaperone involved in pain processing, including modulation of opioid antinociception. However, data supporting the potential use of sigma-1 receptor ligands as suitable opioid adjuvants are based on studies that use non selective ligands.

Role of CB1 and CB2 cannabinoid receptors in the development of joint pain induced by monosodium iodoacetate.

Joint pain is a common clinical problem for which both inflammatory and degenerative joint diseases are major causes. The purpose of this study was to investigate the role of CB1 and CB2 cannabinoid receptors in the behavioral, histological, and neurochemical alterations associated with joint pain. The murine model of monosodium iodoacetate (MIA) was used to induce joint pain in knockout mice for CB1 (CB1KO) and CB2 cannabinoid receptors (CB2KO) and transgenic mice overexpressing CB2 receptors (CB2xP).

Influence of δ-opioid receptors in the behavioral effects of nicotine.

Multiple studies in animal models and humans suggest that the endogenous opioid system is an important neurobiological substrate for nicotine addictive properties. In this study, we evaluated the participation of δ-opioid receptors in different behavioral responses of nicotine by using δ-opioid receptor knockout mice. Acute nicotine administration induced hypolocomotion and antinociception in wild-type mice, which were similar in knockout animals.

Paclitaxel-induced neuropathic pain is age dependent and devolves on glial response.

Background: Paclitaxel is an antimitotic antitumour drug highly effective against a broad range of cancers considered refractory to conventional chemotherapy. One of the main serious side effects of paclitaxel treatment is the induction of peripheral neuropathic pain that often diminishes the patient's quality of life. In this study, we evaluated the severity of the neuropathy induced by paclitaxel and the inflammatory reaction in the dorsal horn of the spinal cord in young, adult and aged male CD1 mice.

Effects of the cell type-specific ablation of the cAMP-responsive transcription factor in noradrenergic neurons on locus coeruleus firing and withdrawal behavior after chronic exposure to morphine.

Repeated exposure to opiates leads to cellular and molecular changes and behavioral alterations reflecting a state of dependence. In noradrenergic neurons, cyclic AMP (cAMP)-dependent pathways are activated during opiate withdrawal, but their contribution to the activity of locus coeruleus noradrenergic neurons and behavioral manifestations remains controversial. Here, we test whether the cAMP-dependent transcription factors cAMP responsive element binding protein (CREB) and cAMP-responsive element modulator (CREM) in noradrenergic neurons control the cellular markers and the physical signs of morphine withdrawal in mice.

Effects of chronic nicotine on food intake and anxiety-like behaviour in CB(1) knockout mice.

We have evaluated the effects of chronic nicotine administration and withdrawal in food intake and preference, metabolic parameters and anxiety-like behaviour in CB(1) knockout mice and wild-type littermates. Mutant mice showed lower levels of glucose, insulin and cholesterol after two weeks of high fat diet and reduced preference for saccharin solution when compared with wild-type mice. Nicotine reduced body weight and induced anxiogenic-like effects in wild-type, but not in CB(1) knockout mice.

Prodynorphin gene disruption increases the sensitivity to nicotine self-administration in mice.

The endogenous opioid system has been reported to participate in nicotine behavioural responses. The aim of the study was to determine the contribution of the endogenous peptides derived from prodynorphin in acute and chronic nicotine responses, mainly those related to its addictive properties. Locomotion and nociception were evaluated after acute nicotine administration in prodynorphin knockout mice.

Genetic and pharmacological approaches to evaluate the interaction between the cannabinoid and cholinergic systems in cognitive processes.

Background And Purpose: The objective of this study was to investigate the possible interactions between the cannabinoid and cholinergic systems in memory and learning processes by using genetic and pharmacological approaches in two different behavioural models, the active avoidance and the object recognition test.

Experimental Approach: The effects induced by nicotine, physostigmine and scopolamine were studied in CB(1) receptor knockout and wild-type mice in the active avoidance paradigm. In addition, the effects of pretreatment with the CB(1) receptor antagonist rimonabant were evaluated on the responses induced by nicotine in the active avoidance and the object recognition tasks in wild-type mice.