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D Kandel

Publications and source records attributed to D Kandel.

35 records · Page 2Linked to original sources
PubMed1978

Effects of repeated administration of cocaine on schedule-controlled behavior of rats.

The effects of cocaine (4.0--32 mg/kg) on schedule-controlled behavior of rats were determined before and during a period of repeated administration of cocaine. In rats trained to lever press on a fixed ratio 40 schedule for food delivery, cocaine (8.0--32 mg/kg) initially decreased response rate in a dose-related manner. During the period of repeated administration, the effects of cocaine on response rate and running rate were attenuated in 2 rats and did not change in 2 others. When dose-effect functions of cocaine were redetermined, a shift to the right was observed in several measures indicating the development of tolerance to these effects of cocaine on performance. In rats trained to lever press on a DRL 20" schedule for food delivery, cocaine (4.0--32 mg/kg) increased response rates, decreased number of reinforcements per session and shifted interresponse time distributions to the left (shorter IRT's in all rats). During the period of repeated administration, the effects of the daily dose of cocaine (16 mg/kg) on all these measures were attenuated. Tolerance to cocaine was further indicated by a shift in the dose effect function of cocaine to the right during the redetermination.

Animals↗
PubMed1978

Tolerance and cross-tolerance to cocaine and d-amphetamine.

The effects of cocaine (4.0-32 mg/kg) and d-amphetamine (0.5-4.0 mg/kg) on milk intake of rats were determined before and during periods of repeated daily administration of each drug. Experimental sessions consisted of 15 minutes access to 50 ml of a sweetened condensed milk solution. After the determination of the disruptive effects of single injections of cocaine or d-amphetamine on milk intake, rats were injected daily with either 16 mg/kg of cocaine 15 minutes before the session, 16 mg/kg of cocaine immediately after the session, 2.0 mg/kg of d-amphetamine 15 minutes before the session or saline before the session. During the period of repeated administration when milk intake had stabilized in each group, dose-effect functions for cocaine and d-amphetamine on milk intake were redetermined. On selected days, test doses of either drug were substituted for the usual daily injection. Test doses were separated by at least 3 days of stable intake after injection of the appropriate drug or saline. During the period of repeated administration, milk intake returned toward control levels for animals receiving daily cocaine or daily d-amphetamine before the session. Further, when the dose-effect functions for cocaine and d-amphetamine on milk intake were redetermined, a shift to the right (i.e., toward larger doses) was observed in all groups that had received drug presession during the repeated administration. This indicates that the animals became tolerant to cocaine and d-amphetamine as well as cross-tolerant to both drugs. The development of tolerance to cocaine was contingent upon the relationship of the time of injection to milk availability. Animals that had received postsession injections of cocaine during repeated administration were more sensitive to the effects of cocaine and d-amphetamine on milk intake.

Animals↗
PubMed1977

Depressive mood and adolescent illicit drug use: a longitudinal analysis.

Through the technique of Goodman's log linear method, longitudinal data are analyzed to clarify the relationship between depressive mood and illicit drug use among youths. A representative sample of adolescents (N = 8206) from New York State secondary schools was followed over one academic year. At one point in time, users of illicit drugs other than marihuana (multiple drug users) were significantly more depressed than either nonusers or users of marihuana only. Differing interactive relationships were found over time depending upon the drugs involved. Depressive mood was related to the onset of marihuana use among nonusers and to the termination of marihuana use among users. Depressive mood also predicted the use of other illicit drugs by marihuana users. While the beginning use of illicit drugs other than marihuana was positively associated with increased depressive mood, continued multiple drug use was related to reduced depressive mood.

Adolescent↗
PubMed1976

The epidemiology of drug use among New York State high school students: Distribution, trends, and change in rates of use.

A two-wave panel survey was carried out on a representative sample of New York State public secondary school students in fall 1971 and spring 1972. The majority of adolsecents have drunk beer or wine (82 per cent) smoked cigarettes (72 per cent) or used hard liquor (65 per cent). Better than one third (35 per cent) report the use of one or more illegal drugs. The illicit drugs most frequently used are marijuana (29 per cent) and hashish (21 per cent). About one in eight adolescents have used pills such as amphetamines and barbiturates, and about one in 12 have tried LSD or other psychedelics. Four per cent have used cocaine and 3 per cent heroin. Use of illicit drugs tends to be experimental and sporadic rather than regular. By contrast, about one in four regularly use beer or wine or smoke cigarettes. Self-reported rates of use increase over the course of a school year, and there is considerable turnover with respect to which adolescents are users. The increased number of hard liquor and marijuana users through the high school years results predominantly from more stability among users, rather than increased conversion of nonusers to users over the teen years.

Adolescent↗
PubMed1975

Stages in adolescent involvement in drug use.

Two longitudinal surveys based on random samples of high school students in New York State indicate four stages in the sequence of involvement with drugs: beer or wine, or both; cigarettes or hard liquor; marihuana; and other illicit drugs. The legal drugs are necessary intermediates between nonuse and marihuana. Whereas 27 percent of high school students who smoke and drink progress to marihuana within a 5- to 6-month follow-up period, only 2 percent of those who have not used any legal substance do so. Marihuana, in turn, is a crucial step on the way to other illicit drugs. While 26 percent of marihuana users progress to LSD, amphetamines, or heroin, only 1 percent of nondrug marihuana users and 4 percent of legal drug users do so. This sequence is found in each of the 4 years in high school and in the year after graduation. The reverse sequence holds for regression in drug use.

Adolescent↗
PubMed1975

Sequence and stages in patterns of adolescent drug use.

Two prospective longitudinal surveys based on New York State high school students indicate well-defined steps underlying adolescent progression and regression in drug use. At least four stages of involvement with drugs can be identified: (1) beer or wine; (2) cigarettes or hard liquor; (3) marijuana; and (4) other illcit drugs. Two stages of legal drugs are necessary intermediates between nonuse and marijuana. Very few youths progress to other illicit drugs without prior experience with marijuana. This sequence is found in each year of high school in the year following graduation. Progression to a higher-ranked drug is directly related to intensity of use at the prior stage. The identification of stages in drug behavior has implications regarding the optimum strategy for studying factors that predict, differentiate, or result from drug use.

Adolescent↗
PubMed1975

Reaching the hard-to-reach: illicit drug use among high school absentees.

As part of a large-scale survey of adolescent drug use in the State of New York, two absentee studies were carried out to estimate levels of drug use among school absentees. Students interviewed in households reported very little drug use. By contrast, absentees self-selecting themselves to participate in a group-administered questionnaire reported much higher illicit drug use than regular students from the same schools. However, comparison of students in the absentee sample with the total target absentee population, and the reverse association between drug use and selected background factors among absentees, suggest that most chronic absentees and heavy users, especially blacks and males, did not participate in the self-selected absentee sample. Attempts to identify factors related to higher drug use among absentees were unsuccessful. While poor school performance brings levels of illicit drug use among regular students to levels comparable to those of the absentees, poor school performances per se does not explain the higher rates of illicit drug use among the absentees. It is clear that school absentees who are generally excluded from school surveys are extremely hard to reach for research purposes.

Achievement↗
PubMed1973

Adolescent marihuana use: role of parents and peers.

In order to examine the relative influence of parents and peers on marihuana use among adolescents, independent data have been obtained from adolescents, their parents, and their best school friends in a sample of secondary school students in New York State. The data indicate that drug use by peers exerts a greater influence than drug use by parents. Friends are more similar in their use of marihuana than in any other activity or attitude. Parental use of psychotropic drugs has only a small influence, mostly related to maternal use. Peer and parental influences are synergistic; the highest rates of marihuana usage are observed among adolescents whose parents and friends are drug users.

Adolescent↗
PubMedDate not supplied

Tolerance and cross-tolerance to the effects of amphetamine, methamphetamine and fenfluramine on milk consumption in the rat.

It has been reported that rats develop tolerance to the milk intake suppressant effects of d-amphetamine, d-methamphetamine, and d, l-fenfluramine. However, it has been hypothesized that the mechanism of action of fenfluramine is different from that of the other two drugs. In the present experiment, rats were given one of these 3 phenylethylamine derivatives each day until tolerance developed to the suppression of milk intake. A second of these drug s was then substituted and milk intake measured. There was cross-tolerance to the drug-induced suppression between d-amphetamine and d-methamphetamine, but not between d-amphetamine and d,l-fenfluramine. The lack of cross tolerance suggests a different mechanism of action for these drugs.

Animals↗
PubMedDate not supplied

Substance abuse by adolescents in Israel and France: a cross-cultural perspective.

Household surveys of urban youths 14-18 years of age were conducted in 1979 with 609 Israeli adolescents and in 1977 with 499 French adolescents. The overall order in the prevalence of use of legal and illegal drugs was identical in both countries. Cigarettes and alcohol were used by a larger proportion of young people than the illegal drugs; marijuana was used much more frequently than any other illicit drug. The same cumulative sequence of drug use appeared in the survey data for French and Israeli adolescents as in comparative data for adolescents in the United States--cigarette and alcohol use preceded the use of illicit drugs. Striking cross-cultural differences appeared in the overall lifetime and current prevalences of use of all drugs, in the frequency of use, and in the age- and sex-specific rates for adolescents in Israel and in France. French youths uniformly reported greater lifetime and current use of all alcoholic beverages, cigarettes, and illegal drugs, more extensive involvement, and smaller sex differences than the Israeli youths. Prevalence of the use of drugs in a culture appears to be associated with four social processes: higher number of times each drug has been used; greater persistence of involvement, as reflected by the proportions of current users among those who ever tried a particular drug; earlier age of first use; and a spread of the phenomenon throughout all groups in society that attenuates group differences in drug experiences. These cross-cultural results suggest a relatively conservative position with regard to accessibility and availability of substances: reducing availability may be one way to reduce individual consumption by impinging not on individual persons directly but on society.

Adolescent↗