Pharmacology, biochemistry, and behavior
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Pharmacol. Biochem. Behav. · Jul 2013
2-AG into the lateral hypothalamus increases REM sleep and cFos expression in melanin concentrating hormone neurons in rats.
Orexins/hypocretins (OX) and melanin-concentrating hormone (MCH) neurons located in the lateral hypothalamus seem to modulate different stages of the sleep-wake cycle. OX are necessary for wakefulness and MCH appears to regulate rapid eye movement sleep (REMS). Likewise, endocannabinoids, the endogenous ligands for cannabinoid receptors 1 and 2 (CB1R, CB2R), also modulate REMS in rats. ⋯ We also utilized the CB1R inverse agonist AM251 to further support the involvement of this receptor, and we performed double immunofluorescence experiments to detect c-Fos, as a marker of neural activation, in OX and in MCH neurons to determine which neurons were activated. Our results indicate that 2-AG increases REMS through CB1R activation, and increases c-Fos expression in MCH neurons. These results suggest that endocannabinoid activation of the CB1R in the lateral hypothalamus, which activates MCH neurons, is one mechanism by which REMS is triggered.
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Pharmacol. Biochem. Behav. · Jul 2013
Short and long-term motor and behavioral effects of diazoxide and dimethyl sulfoxide administration in the mouse after traumatic brain injury.
Traumatic brain injury (TBI) is a worldwide phenomenon that affects all ages and socioeconomic classes and results in varying degrees of immediate and delayed motor, cognitive, and emotional deficiencies. A plethora of pharmacologic interventions that target recognized initiators and propagators of pathology are being investigated in an attempt to ameliorate secondary injury processes that follow primary injury. Diazoxide (DZ), a K(ATP) channel activator, has been shown to provide short- and long-term protective effects in a variety of in vitro and in vivo cerebral ischemia models. ⋯ In addition, animals exposed to DMSO or DZ+DMSO exhibited slower swimming speed in the Morris water maze on the final day of testing. There was no therapeutic effect, however, of the treatment or vehicle on open field behavior or learning and memory function in the Morris water maze. In summary, CCI produced significant long-term impairment of motor, memory, and behavioral performance measures, and DZ administration, under the conditions used, provided no functional benefits following injury.
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Pharmacol. Biochem. Behav. · May 2013
Optimization and characterization of a rat model of prostate cancer-induced bone pain using behavioral, pharmacological, radiological, histological and immunohistochemical methods.
The major limitation of currently utilized rodent models of prostate cancer (PCa)-induced bone pain (PCIBP) involving intra-osseous injection of PCa cells, is their relatively short-term applicability due to progressive deterioration of animal health necessitating euthanasia. Here, we describe establishment of an optimized rat model of PCIBP where good animal health was maintained for at least 90-days following unilateral intra-tibial injection (ITI) of PCa cells. We have characterized this model using behavioral, pharmacological, radiological, histological and immunohistochemical methods. ⋯ Importantly, the histological and radiological assessments confirmed that tumor formation and development of osteosclerotic metastases was confined to the APCC-injected tibial bones. In our rat model of PCIBP, single bolus doses of morphine, gabapentin, meloxicam and amitriptyline produced dose-dependent relief of mechanical allodynia and thermal hyperalgesia in the bilateral hindpaws. The optimized rat model of PCIBP characterized herein has potential to provide new insights into the pathophysiological mechanisms associated with long-term (mal)adaptive pain due to advanced PCa-induced bony metastases and for screening novel compounds with potential for improved alleviation of this condition.
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Pharmacol. Biochem. Behav. · Apr 2013
Etazolate, a phosphodiesterase 4 inhibitor reverses chronic unpredictable mild stress-induced depression-like behavior and brain oxidative damage.
Etazolate, a pyrazolopyridine class compound is selective inhibitor of type 4 phosphodiesterase (PDE4). Previous study in our laboratory has demonstrated that etazolate produced antidepressant-like effect in rodent models of behavioral despair. The present study was designed to investigate whether etazolate could affect the chronic unpredictable mild stress (CUMS)-induced depression in mice. ⋯ No alteration was observed in locomotor activity. Additionally, in the present study, the efficacy of etazolate (1mg/kg., p.o.) on the behavioral and biochemical paradigms was found comparable to that of fluoxetine, used as standard antidepressant. In conclusion, the results of the present study suggested that etazolate alleviated the CUMS-induced depression in mice, which is at least in part mediated by modulating oxidative-nitrosative stress status in mice brain.
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Pharmacol. Biochem. Behav. · Apr 2013
Characterization of cannabinoid-induced relief of neuropathic pain in a rat model of cisplatin-induced neuropathy.
Clinical use of antineoplastic drugs is associated with the development of numerous adverse effects that many patients find intolerable, including peripheral neuropathy. Cannabinoids have relieved neuropathic pain in different animal models. But their therapeutic activities could be affected by their psychoactive properties. ⋯ In a rat model of cisplatin-induced neuropathy, cannabinoids have an antinociceptive effect, but the cannabinoid receptors involved could be different depending on the route of administration. Non-psychoactive doses of cannabinoid agonists are capable of alleviating the signs of peripheral neuropathy when systemically applied. Interestingly, local administration of selective CB1 agonists or systemic administration of CB2 agonists, which are non-psychoactive, may serve as new therapeutic alternatives for symptom management in painful neuropathy associated with cisplatin treatment.