Background: The lateral hypothalamus (LH), which produces orexin, is vital for body solution homeostasis. Lateral hypothalamus (LH) lesion causes adipsia and its stimulation increases water intake. Objective: This study aimed to investigate the effect of an intracerebroventricular (ICV) injection of orexin-A (OXA) on water-drinking behavior in water-deprived rats. Metods: A total of 32 male W...

EXPERIMENTAL DATA Orexinergic neurotransmission is involved in mediating temperature responses to methamphetamine (Meth). In experiments in rats, SB-334867 (SB), an antagonist of orexin receptors (OX1R), at a dose of 10 mg/kg decreases late temperature responses (t > 60 min) to an intermediate dose of Meth (5 mg/kg). A higher dose of SB (30 mg/kg) attenuates temperature responses to low dose (1...

Orexin/hypocretin signaling at the orexin 1 receptor (OX(1)R) has recently been implicated in addiction and relapse. We examined the role of the orexin system in cocaine-seeking elicited by a drug-associated context following abstinence or extinction from chronic cocaine self-administration. Male Sprague-Dawley rats self-administered cocaine in 2-h sessions for 10 days, followed by extinction t...

The orexin/hypocretin system is involved in multiple cocaine addiction processes that involve drug-associated environmental cues, including cue-induced reinstatement of extinguished cocaine seeking and expression of conditioned place preference. However, the orexin system does not play a role in several behaviors that are less cue-dependent, such as cocaine-primed reinstatement of extinguished ...

The orexin/hypocretin system has recently been implicated in reward-seeking, especially for highly salient food and drug rewards. Given that eating disorders affect women more than men, we reasoned that the orexin system may be strongly engaged in female rats, and during periods of food restriction as we recently reported in male rats. Therefore, the present study examined the involvement of th...

Learned food cues can drive feeding in the absence of hunger, and orexin/hypocretin signaling is necessary for this type of overeating. The current study examined whether orexin also mediates cue-food learning during the acquisition and extinction of these associations. In Experiment 1, rats underwent two sessions of Pavlovian appetitive conditioning, consisting of tone-food presentations. Prio...

Seasonal affective disorder (SAD), a major depressive disorder recurring in the fall and winter, is caused by the reduction of light in the environment, and its depressive symptoms can be alleviated by bright light therapy. Both circadian and monoaminergic systems have been implicated in the etiology of SAD. However, the underlying neural pathways through which light regulates mood are not well...