EEG and other effects of naltrexone and heroin in man

Event-Related Oscillations in Alcoholism Research: A Review

Alcohol dependence is characterized as a multi-factorial disorder caused by a complex interaction between genetic and environmental liabilities across development. A variety of neurocognitive deficits/dysfunctions involving impairments in different brain regions and/or neural circuitries have been associated with chronic alcoholism, as well as with a predisposition to develop alcoholism. Several neurobiological and neurobehavioral approaches and methods of analyses have been used to understand the nature of these neurocognitive impairments/deficits in alcoholism. In the present review, we have examined relatively novel methods of analyses of the brain signals that are collectively referred to as event-related oscillations (EROs) and show promise to further our understanding of human brain dynamics while performing various tasks. These new measures of dynamic brain processes have exquisite temporal resolution and allow the study of neural networks underlying responses to sensory and cognitive events, thus providing a closer link to the physiology underlying them. Here, we have reviewed EROs in the study of alcoholism, their usefulness in understanding dynamical brain functions/dysfunctions associated with alcoholism as well as their utility as effective endophenotypes to identify and understand genes associated with both brain oscillations and alcoholism.

An analysis of naltrexone and naloxone's possible agonistic actions in the dog

Naltrexone (0.01-2.0 mg/kg, i.v.) produced dose-dependent EEG slowing in the conscious dog as did morphine (0.5-8 mg/kg, i.v.) and fentanyl (5-20 micrograms/kg, i.v.). However, the dose-response curve for naltrexone was not parallel to the morphine or fentanyl dose-response curves. Morphine and fentanyl but not naltrexone also produced dose-dependent miosis and increased the skin twitch reflex latency. When administered into the fourth cerebral ventricle naltrexone (60 micrograms), morphine (80 micrograms) and ethylketazocine (30 micrograms) produced EEG slowing. Again, naltrexone did not alter the skin twitch latency whereas morphine lengthened it and ethylketazocine reduced it. The pharmacological profiles obtained from different routes of administration indicate that naltrexone is clearly different from morphine, fentanyl and ethylketazocine. However, naltrexone may act as a partial agonist in the production of EEG slowing at a previously unidentified opioid receptor.