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J L Slangen

Publications and source records attributed to J L Slangen.

At least 91 records · Page 5Linked to original sources
PubMed1983

Effects of d-amphetamine and morphine on discrimination: signal detection analysis and assessment of response repetition in the performance deficits.

Signal detection analysis was used to examine the effects of d-amphetamine and of morphine on auditory discrimination in female rats. The probability of response repetition in the discrete trial two-choice discrimination procedure was used as an additional behavioral measure. d-Amphetamine (0.4-3.2 mg/kg) and morphine (1.88-15.0 mg/kg) decreased the sensitivity measures (A' and SI) but did not consistently affect the response bias measures (B" and RI). The probability of response repetition was increased by d-amphetamine and was not affected by morphine. It is concluded that the response bias measure B", derived from signal detection theory, and the empirical response bias measure RI, do not discriminate between the different ways in which d-amphetamine and morphine affect discriminative responding, under the conditions of this study.

Animals↗
PubMed1982

The role of fentanyl training dose and of the alternative stimulus condition in drug generalization.

Different groups of rats were trained to discriminate fentanyl (F) (0.03, 0.02, or 0.01 mg/kg) from saline or to discriminate 0.03 mg/kg fentanyl (F) from alternative stimulus conditions (saline, 0.15 mg/kg nicotine, or 0.01 mg/kg F). When percentage of responses on the drug lever and percentage of time spent responding on the drug lever were used as dependent variables, it was found that training dose and alternative stimulus condition both affected the ED50 and the slope of the F generalization gradient. ED50 and slope values based on group data were not significantly different from values based on individual data. Differences between from values based on individual data. Differences between the results of the first and second 2.5-min period of the extinction test were not significant. ED50 and slope values were unaffected by the preceding training session, except in the group trained to discriminate 0.03 from 0.01 mg/kg F. A lever selection measure showed a significant effect of alternative stimulus condition on ED50 values only. Training dose and alternative stimulus condition also affected the generalization to morphine. Under none of the conditions explored in this study did generalization occur to amphetamine or nicotine. The results are discussed in terms of the relative nature of drug generalization.

Amphetamine↗
PubMed1981

Habituation of the head-poke response: effects of an amphetamine-barbiturate mixture, PLG and fenfluramine.

A test situation was developed in which the effects of drugs on habituation of exploratory behavior (head-poke responses) could be assessed independently of their effects on general activity (locomotion and rearing). Habituation, spontaneous recovery from habituation and stimulus specificity of habituation were studied. An amphetamine-barbiturate mixture attenuated habituation of the head-poke response without influencing general activity. Pro-Leu-Gly-NH2 (PLG), an oxytocin fragment, increased locomotor activity and did not alter the course of habituation of the head-poke response. Since exploratory behavior and general activity can be pharmacologically dissociated in the test situation used, it is concluded that the test situation is suitable for studying the effects of drugs on habituation of exploratory behavior. The amphetamine-barbiturate mixture did not influence the stimulus specificity of habituation of the head-poke response. Fenfluramine however increased the effects of stimulus change on the head-poke response while not influencing habituation of this response. These results show that habituation and stimulus specificity of habituation of exploratory behavior can be pharmacologically dissociated.

Amobarbital↗
PubMed1981

The influence of information on habituation of the "Wiener" filtered visual even related potential and the skin conductance reaction.

In this study the influence of the information value of visual stimuli on habituation in event related potentials (ERPs) at Fz, Cz and Oz locations and the skin conductance reaction (SCR) was investigated. An improved 'Wiener' filter was used to reduce the number of stimulus presentations. This enabled us to study P300 and SCR decrement in the same period of time. SCRs and Wiener filtered ERPs were determined over six stimulus presentations. Half of the 26 subjects received for 36 times a stimulus with a high information value in terms of complexity and the other half of the subjects 36 stimuli with a low information value. The results of this study show that decrement of the P300 amplitude occurs in about the same period of time as the SCR magnitude decrement. P300 habituation was manifested only in the fronto-central leads, the occipital P300 did not show habituation. A second difference in the topography of the P300 was that the effect of stimulus information was only found in the fronto-central leads and not in the occipital lead. As earlier studies, we did not find an effect of information on SCR habituation. The results show that the fronto-central P300 showed two important characteristics of the orienting response (OR). They are that habituation occurs in about the same period of time as in which a classical OR index as the SCR habituates and P300 amplitudes are larger when the information value of the stimuli is higher.

Adult↗
PubMed1981

A statistical Wiener filter using complex analysis of variance.

The Wiener filter is a digital filter in the frequency domain which enables the detection of signals in noise on the basis of a relatively small number (N) of signals-in-noise series. However, the variance associated with the Wiener filter increases sharply with low N or low signal-to-noise ratio, sometimes resulting in large negative transfer coefficients (H(w)'s). This causes an unacceptable distortion of the extracted signal. The classical solution for this problem is rather arbitrary; clipping all H(w)'s less than zero. It can be shown that this approach has limited practical value and does not lead to optimal filtering of the signal. The solution presented in this paper is based on the fact that the large negative H(w)'s in the case of a small N are caused by using an estimate for the noise-power which deviates from the actual noise-power. This makes the use of a statistical procedure feasible. By using complex analysis of variance it is possible to test which part of the spectrum is due to the signal and which part of the spectrum is due to the noise. H(w)'s not reaching a preset significance criterion are set to zero. The statistical Wiener filter acts as an adaptive multi-band-pass filter with band-passes determined by (a posteriori) detected signal components. It is demonstrated that this procedure leads to better suppression of the noise in signal-in-noise series.

Analysis of Variance↗
PubMed1978

Intravenous self-administration of drugs in rats.

A standardized self-administration procedure in rats was used to determine the intravenous self-administration liability of graded doses of various drugs. Self-administration was reliably established with the tested addictive drugs (morphine, heroin, fentanyl and d-amphetamine), but not with the nonaddictive drugs (chlorpromazine and nalorphine). However, 1 out of 14 animals on nalorphine clearly demonstrated self-administering behavior. Self-administration was observed with delta1-tetrahydrocannabinol, but the percentage of animals (40% on the highest dose) that initiated this behavior and the amount of drug intake were low in comparison with amphetamine and narcotics. Concerning the narcotic drugs, approximate ED50 values for self-administration under the described conditions were calculated (morphine: 0.65; heroin: 0.05; fentanyl: 0.0025 mg/kg/injection). Total daily drug intake was related to the unit dose delivered per injection in that a higher drug dosage led to more drug intake. In experiments with heroin, this relationship was not caused by prior forced injections. The approximate ED50 value for amphetamine appeared to be 0.145 mg/kg/injection. Narcotic drug administration resulted in a disturbance of the patterns of food and water intake. Shortly after drug administration food intake was stimulated, followed by an increased consumption of water. The patterns of food and water intake remained disturbed in animals showing self-injecting behavior. With amphetamine both the quantity of food and the frequency of eating were reduced. These effects were observed only temporarily in animals tested without prior forced injections. The present results indicate that measuring the reinforcing efficacy of drugs under strictly defined experimental conditions provides quantitative criteria for intravenous self-administration of drugs in rats.

Animals↗
PubMedDate not supplied

Norepinephrine uptake by hypothalamic tissue from the rat related to feeding.

Norepinephrine (NE) uptake by rat hypothalamus in vitro was studied in relation to food intake. Significant daily variations in NE uptake were observed in caudal hypothalamus from freely feeding rats. A maximal elevation occurred at the beginning of the night when food intake is also increasing to a maximum. NE uptake by caudal hypothalamus from relatively hungry rats previously adjusted to restricted feeding during the daytime was enhanced in afternoon and evening when compared with uptake by tissue from ad lib feeding animals. Determination of NE uptake by caudal hypothalamus from freely feeding individual rats and registration of individual meals taken by these rats revealed a relation between hypothalamic neuronal activity and the feeding pattern of the rat. A positive correlation was observed between NE uptake in vitro and feeding rate during a 2- to 4-hr interval. It also appeared that NE uptake by caudal hypothalamus is dependent on the time elapsed after the last meal. The data were evaluated in view of physiological studies concerning the onset of feeding and the hypothesis of hypothalamic adrenergic control of food intake.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Single trial ERP estimation in the frequency domain using orthogonal polynomial trend analysis (OPTA): estimation of individual habituation.

A new Event Related Potential (ERP) model is described in which ERPs are estimated as single cortical responses. This model is based on an Orthogonal Polynomial Trend Analysis of Variance (OPTA) in the frequency domain. The orthogonal polynomials are limited to the fifth order in this study. The means and trend-coefficients which are used to estimate the ERPs are tested for significance with the F-statistics. Coefficients not reaching a preset significance criterion are set to zero. Subsequently significant means and trend-coefficients multiplied with the polynomials are inversely transformed to the time domain for each trial. The method is demonstrated with artificial signal-in-noise EEG (electroencephalogram) series in which the signal component (the ERP) decreases in a relatively short time span. The estimated signals approximate closely the input signals and a signal-to-noise improvement on single trial level is reached of about a factor 10. Comparison with the statistical 'Wiener' filtering method shows that the OPTA detects weaker signals. Single trial ERPs estimated with the OPTA from EEGs collected in a habituation paradigm suggest that the averaged evoked potential model may be inadequate in detecting ERP change over a few trials. It is shown that the frontal P3b wave habituated in 7-9 trials, a habituation speed which is comparable to the habituation rate of the visual orienting reaction and the electrodermal orienting reaction.

Analysis of Variance↗