John Brick

Effects of chronic exposure to stressors on avoidance-escape behavior and on brain norepinephrine.

&NA; A single exposure to a severe stressor (either cold swim or inescapable shock) impairs subsequent performance in a shuttle avoidance‐escape task (1), a deficit attributed to reduction in brain noradrenergic activity produced by these stressors. In the present paper, two experiments are described which examine how repeated exposure to such stressors affects (a) shuttle avoidance‐escape performance (Experiment 1), and (b) aspects of brain norepinephrine metabolism (Experiment 2). Experiment 1 showed that, whereas subjects receiving the single exposure to cold swim or shock showed a large avoidance‐escape deficit, subjects that received repeated exposure to these stressors for 14 days performed similarly to the control group that received no stressor. Experiment 2 showed that, whereas subjects that received one session of the inescapable shock stressor showed a lower level of norepinephrine in hypothalamus and cortex than did subjects that received no shock, subjects that received repeated exposure to inescapable shock or cold swim showed neurochemical “habituation.” Subjects that received repeated shock showed elevated tyrosine hydroxylase activity and no depletion of norepinephrine level, and both repeated shock and cold swim caused a decrease in uptake of 3H‐norepinephrine by slices of cortex in vitro. Thus, it is concluded that the behavioral and neurochemical changes that were observed after the stressful conditions studied are consistent with the hypothesis that changes in avoidance‐escape responding following exposure to these stressful events are due to changes in brain noradrenergic activity.

Ethanol and the response to electric shock in rats.

Abstract Moderate doses of ethanol (2 g/kg) were found to have an analgesic effect in rats. When tested with either foot- or tail-shock, the animals showed progressive analgesia with increasing levels of ethanol in the blood. The vocalization response seemed to be the most sensitive indicator of this parameter. The analgesic effect of ethanol was decreased by half when serotonin levels in the brain were decreased after treatment of animals with p-chloroamphetamine. Inhibition of catecholamine synthesis with α-methyl tyrosine had no effect on the analgesic effect of ethanol.

Intoxication Is Not Always Visible: An Unrecognized Prevention Challenge

T HE USE OF alcohol or other drugs (AOD) to alter consciousness and produce intoxication is not new. Alcohol, for example, is the most widely used and abused drug on earth and has been consumed for its intoxicating effects for thousands of years. One consequence of AOD intoxication is impaired driving. One of the challenges facing prevention specialists is that many factors contribute to intoxication as well as to whether a person is ‘‘visibly intoxicated.’’ ‘‘Visible intoxication’’ (meaning a series of perceptible acts and behaviors consistent with gross impairment) is, in some cases, different from ‘‘obvious intoxication,’’ a term used in some state statutes (and some older studies to mean visibly intoxicated), that relates to a combination of all the factors used to determine whether a person is or is likely to be alcohol impaired. ‘‘Intoxication’’ is not always visible even to trained observers. The goals of this review are (i) to educate prevention specialists about the state of knowledge in determining intoxication, (ii) to provide an authoritative treatise on the subject of visible intoxication, and (iii) to address the medicolegal consequences of such intoxication—primarily the prevention of impaired driving. Historically, most of the direct consequences of intoxication have been limited to individual drinkers who, if they lived long enough, would eventually incur significant medical consequences (Brick, 2008). However, the introduction of motor vehicles and the eventual proliferation of mechanized transportation dramatically changed society. No longer were the effects of alcohol overuse limited to the drinker, but now others (passengers, occupants of other vehicles, and pedestrians) were included as well. Today about 14,000 alcohol-related fatal crashes occur per year (Yi et al., 2006). The actual number of crashes directly due to intoxication is probably lower as most recent epidemiological studies of this type include drivers with blood alcohol concentrations (BACs) of more than zero, and statistical methods, such as intupation, assume intoxication based on driver and crash profiles. But even when objective blood alcohol evidence is missing (US Department of Transportation ⁄National Highway Traffic Safety Administration, 2002), drunken driving is a major health hazard. Diverse approaches have been applied to prevent drunken driving (Hingson et al., 1996a,b, 1999; Holder et al., 2000; NIAAA, 2000) but only three approaches specifically relate to identifying signs of alcohol intoxication: DWI laws, dramshop ⁄ related host liability, and Alcohol Beverage Control Board laws. A review of differences between DWI-related issues and visible intoxication (the focus of dram shop laws) is important to the general public’s awareness and understanding of this problem, and the reduction of motor vehicle and other injuries due to intoxication. In this article, we review the development, scientific foundation, implications, and interrelationships among these approaches.