Rats can learn to forage among olfactory cues to associate one with reward in only 3 massed trials. The learning is achieved in less than 10 min and results in a memory trace lasting at least 1wk week. To study the neuro-anatomical circuits involved in the memory formation we used immunoreactivity to the immediate early gene c-fos as a marker for neuronal activity induced by the learning. The p...

Objective(s): Intracerebroventricular injection of orexin-A (hypocretin-1) antagonist has been shown to inhibit stress-induced analgesia. However the locations of central sites that may mediate these effects have not been totally demonstrated. This study was performed to investigate the role of rostral ventromedial medulla (RVM) orexin receptor 1 in stress-induced analgesia (SIA). Materials and...

Introduction: Oxytocin is a active neuropeptide of central nervous system. In this study the effects of naloxone (opioid receptor antagonist) and yohimbine (α-2 adrenergic receptor antagonist) on analgesic effect of oxytocin applied into the locus coeruleus (LC) nucleus were investigated. Methods: Adult male Wistar rats were used. Animals divided into different groups receiving saline, oxy...

In the present study, the effects of caerulein and CCK receptor antagonist< on tolerance to the anti-pentylenetetrazol activity of diazepam has been studied. Different doses of diazepam (20, 30, 35, 40 and 50 mg/kg) were administered intraperitoneally for a period of 6 days in order to induce tolerance to diazepam. 48 h after the last dose of diazepam, a test dose of diazepam was tested for...

In vivo microdialysis was used to study the effects of morphine on glutamate release from the ventral tegmentum area (VTA) in freely moving rats. Intraperitoneal (i.p.) injection of acute and repeated morphine at increasing doses significantly enhanced glutamate release. Only a minor tolerance developed to this dosage of morphine. AP-S (2-amino-5-phosphonovaleric acid, 0.5 mg/kg i.p.), a N...

the parafascicular nucleus (pfn) of thalamus, as a supraspinal structure, has an important role in processing of nociceptive information. in addition, μ-opioid receptor contributes to supraspinal modulation of nociception. in the present study, the effects of microinjection of naloxone (a non-specific opioid-receptor antagonist) and naloxonazine (a specific μ-opioid receptor antagonist) were in...

estrogen (e2) has neuroprotective effects on blood-brain-barrier (bbb) after traumatic brain injury (tbi). in order to investigate the roles of estrogen receptors (ers) in these kind of effects, er-α antagonist (mpp) and, er-β antagonist (phtpp), or non-selective estrogen receptors antagonist (ici 182780) were administered as regulators of cns cytokines levels and neuroinflammation after tbi. m...

in vivo microdialysis was used to study the effects of morphine on glutamate release from the ventral tegmentum area (vta) in freely moving rats. intraperitoneal (i.p.) injection of acute and repeated morphine at increasing doses significantly enhanced glutamate release. only a minor tolerance developed to this dosage of morphine. ap-s (2-amino-5-phosphonovaleric acid, 0.5 mg/kg i.p.), a nmda r...

Rats can learn to forage among olfactory cues to associate one with reward in only 3 massed trials. The learning is achieved in less than 10 min and results in a memory trace lasting at least 1wk week. To study the neuro-anatomical circuits involved in the memory formation we used immunoreactivity to the immediate early gene c-fos as a marker for neuronal activity induced by the learning. The p...

The parafascicular nucleus (PFN) of thalamus, as a supraspinal structure, has an important role in processing of nociceptive information. In addition, μ-opioid receptor contributes to supraspinal modulation of nociception. In the present study, the effects of microinjection of naloxone (a non-specific opioid-receptor antagonist) and naloxonazine (a specific μ-opioid receptor antagonist) were in...