There are several conflicting evidences showing the effect of morphine on learning and memory processes. In the present study the effect of chronic morphine administration on passive avoidance, active avoidance and spatial learning and memory of morphine dependent male rats using Passive Avoidance shuttle box and Morris Water Maze tasks were investigated, respectively. Male rats received morphi...

introduction: the aim of this study was to evaluate the changes in camp and some other cellular ingredients following adenyl cyclase activation in paragigantocellularis (pgi) neurons of morphine dependent and withdrawn rats. material and methods: the 3.5 mm thick brainstem slice prepared from pgi area (-10.04 to -13.24 from bregma) of control and morphine dependent rats (n=5 in each group). wer...

introduction: activity of the paragigantocellularis (pgi) nucleus located in the rostral ventrolateral medulla is the mediator of dependence, tolerance and withdrawal syndrome. the most important systems which change their activity during morphine consumption include glutaminergic, opioidergicand purinergic (especially adenosine) receptors in the pgi nucleus. however, it has been shown that the...

In the present study, involvement of the N-methyl-d-aspartate (NMDA) receptors of the CA1 region of dorsal hippocampus (intra-CA1) in the acquisition or expression of morphine-induced conditioned place preference in rats was studied. Male Wistar rats were used in these experiments. NMDA-receptor agonist (NMDA) and antagonist (MK-801) were injected into the CA1 region of the dorsal hippocampus (...

Several lines of evidence have indicated that many nuclei in the brain including preoptic nucleus, AV3V, subfornical organ, septal area and lateral hypothalamus are the targets of efferents from chemo-sensitive and pressure-sensitive systems. These areas may concern with regulation of fluid homeostasis. In the present study, intracerebroventricular injections were carried out in all experiments...

introduction: opiates cause dependency via affect on central nervous system. locus coeruleus nucleus is a main group of noradrenergic neurons in the brain that plays an important role in the expression of opioid withdrawal signs. during opioid withdrawal, brain waves change in addition to physical and behavioral signs. in this study, we examined the effects of locus coeruleus electrical stimula...

in this study the effect of adenosine and caffeine on spontaneous activity of paragigantocellularis (pgi) neurons was investigated. the spontaneous activity of pgi neurons was significantly decreased by microinjection of adenosine (10 nm, 0.5 µl) into pgi nucleus of both control and morphine-dependent rats. the decrease in firing rate of pgi neurons of morphine-dependent rats was greater than t...

introduction: nucleus reticularis paragigantocellularis (pgi) is one of the major components of the rostral ventromedial medulla (rvm), which is involved in nociceptive processing and pain modulation. the aim of this study was to examine the effect of c fiber destruction on responsiveness of nucleus reticularis paragigantocellularis (pgi) to formalin, as a noxious stimulus, in normal and morphi...

Morphine activates mu-opioid receptors (MORs) without promoting their rapid endocytosis in a number of cell types. A previous study suggested that morphine can drive rapid redistribution of MORs in the nucleus accumbens, but it was not possible in this in vivo study to identify a specific membrane trafficking pathway affected by morphine, to exclude possible indirect actions of morphine via opi...