Effects of cocaine on sensory motor function in baboons

Effects of Cocaine on Simple Reaction Times and Sensory Thresholds in Baboons

“…Previous experiments showed that single injections of cocaine produce shortened reaction times that followed a specific time course over a session (Hienz et al, 1993). To distinguish the possibility of such effects in the present study, the data were examined for both increases and decreases in the reaction-time and sensory-threshold measures over the course of each individual session.…”

“…Conversely, for possible decreases in these measures, the block of trials in each session for which the greatest decrease occurred was defined as the maximum effect of the prior drug dose in, for example, shortening reaction times. This analysis avoids the averaging of cocaine's effects over sessions when the drug's effects have been shown to vary (Hienz et al, 1993). The resulting maximum and minimum drug-effect values were then subtracted from mean saline-performance values to produce change scores.…”

“…Medi (0.32 to 1.0 mg/kg) were most ef shortening reaction times, whereas doses either shortened or lengthene times were seen, depending upon th Furthermore, chronic cocaine dosing had similar effects on both auditory; reaction times, suggesting that coc action-time-shortening effects were dality specific. (Hienz et al, 1993) te the mean and d-methamphetamine (Hienz et al, 1985) given once or twice weekly. For comparison, Figure 9 shows these previous results compared to the present data.…”

“…Shown are changes in auditory and visual reaction times as a function of cocaine dose for both acute and chronic ly cocaine administrations. To make the data comparable ;ignificant to the acute cocaine data of Hienz et al (1993) Sensitization to cocaine's stimulant effects (an increased responsiveness often indicated by a shift in the dose-effect function to the left) often occurs for "naturally occurring" behavior in a variety of species, including monkeys Uohanson & Fischman, 1989); for many operant performances, on the other hand, tolerance is often the more typical finding (e.g., Hoffman, Branch & Sizemore, 1987;Thompson, 1977). One of the more widely supported hypotheses concerning behavioral tolerance is that if a drug initially decreases reinforcement frequency for a behavior, tolerance is more likely to develop (Schuster, Dockens, & Woods, 1966).…”

“…Given acutely, cocaine can produce dose-related decreases in reaction times in nonhuman pri- mates responding to visual and auditory stimuli (Hienz, Spear, Brady, & Bowers, 1993). More generally, cocaine and other stimulants are known to increase the frequency of general motor behavior in many species, especially repetitive stereotypic movements (Bauer & Fuster, 1978;Kilbey & Ellinwood, 1977;Koek & Slangen, 1984;Ljunberg & Enquist, 1987;Post & Rose, 1976;Ridley, Baker, Owen, Cross, & Crow, 1982;Stripling & Ellinwood, 1977).…”