Effects of physostigmine on scopolamine–induced changes in quantitative electroencephalogram and cognitive performance

Muscarinic and nicotinic receptors synergistically modulate working memory and attention in humans

“…In addition to effects on memory and learning, scopolamine also impaired sustained attention as evidenced by impairments in the Digit Vigilance task and psychomotor function as evidenced by impairments in SRT and CRT tasks. These findings are again consistent with previous studies showing deficits in sustained attention (Broks et al, 1988 ;Ebert et al, 1998 ;Wesnes and Revell, 1984 ;Wesnes and Warburton, 1983 ;Wesnes et al, 1988) and psychomotor performance (i.e. SRT and CRT) with scopolamine (Broks et al, 1988 ;Ebert et al, 1998 ;Flicker et al, 1990 ;Little et al, 1998 ;Mintzer and Griffiths, 2003 ;Nuotto, 1983 ;Wesnes et al, 1988).…”

“…Mecamylamine and scopolamine were chosen for this study, as they are the most selective antagonists available for human use, with high affinity for nicotinic and muscarinic receptors respectively (Brown, 1992 ;Varanda et al, 1985 ;Young et al, 2001). The doses of mecamylamine and scopolamine chosen for this study were based on (1) previous findings reporting cognitive impairments following mecamylamine doses ranging from 5 mg to 20 mg (Newhouse et al, 1992, Pickworth et al, 1997 and scopolamine doses ranging from 0.3 mg to 0.6 mg (Ebert et al, 1998 ;Wesnes et al, 1988) and (2) minimizing the chance of sedation interfering with task performance (especially in the MS condition).…”

Pharmacokinetic‐Pharmacodynamic Modeling of the Electroencephalogram Effects of Scopolamine in Healthy Volunteers

“…Investigations in young healthy volunteers who received scopolamine have been described to influence delta, theta, alpha, and beta frequency bands in EEG. 7,8,[10][11][12][13] After both routes of administration of scopolamine, we observed a significant decrease in total power in the alpha frequency band in all electrode positions (central, frontal, occipital). The scopolamineinduced influence on delta and beta frequency bands observed could only be described as a trend.…”

“…In previous studies, scopolamine was usually administered subcutaneously. 6,9,10 In a recent study, we observed maximum scopolamine serum concentrations of 3.27, 8.99, and 18.81 ng/ml after subcutaneous injection of 0.4, 0.6, and 0.8 mg scopolamine, respectively. 9 We also observed a large variability of the C max values after subcutaneous administration that could limit the application of the sigmoidal E max model.…”

Scopolamine model of dementia: electroencephalogram findings and cognitive performance

“…[ 13] have shown a dose‐related increase in relative power in the 0.5–3.5 and 4.0–7.5 Hz spectral segments (delta and theta frequency bands) and a concomitant reduction in the relative power in the 8.0–13.5 Hz frequency band (part of the alpha and beta frequency bands). We also observed an increase in spectral power density in the delta frequency band (1.25–4.50 Hz) 1 h after subcutaneous administration of 0.6 mg of scopolamine compared with baseline [ 42]. In a recent study in young healthy male volunteers, an increase in spectral delta (1.25–4.50 Hz) and theta power density (4.75–6.75 Hz) and a decrease in spectral alpha 1 (7.00–9.50 Hz), alpha 2 (9.75–12.50 Hz), beta 1 (12.75–18.50 Hz) and beta 2 power density (18.75–35.00 Hz) were found in qEEG after subcutaneous administration of scopolamine compared with placebo [ 45].…”