WILBERT

Wildauer Bücher+E-Medien Recherche-Tool

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science, Ltd
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Previously, it was reported that both norepinephrine transporter (NET) and dopamine transporter (DAT) knockout (KO) mice were sensitive to the reinforcing effects of cocaine. However, assessing the locomotor-stimulant effects of cocaine in these subjects has proven difficult due to significant differences in their baseline activity compared to wild-type controls. The present studies were designed to clarify the role of NET and DAT in the stimulant effects of acute and repeated cocaine utilizing these knockout mice, and thereby assess the role of these substrates in the locomotor stimulant effects of cocaine. Mice were habituated to the test environment for sufficient time to ensure equal baselines at the time of cocaine administration. Mice then received cocaine (3–25 mg/kg) intravenously according to a within-session cumulative dose–response design. Cocaine dosing was repeated at 48-h intervals for four sessions to assess behavioural sensitization. NET-KO mice exhibited a reduced response to acute cocaine administration compared to wild-type (WT) controls. However, comparable sensitization developed in NET-KO and WT mice. The DAT-KO and DAT-heterozygote (HT) mice displayed no locomotor activation following either acute or repeated cocaine administration. These data suggest a role for the NET in the acute response to cocaine, but no involvement in sensitization to cocaine. In contrast, DAT appears to be necessary for both the acute locomotor response to cocaine and the subsequent development of sensitization. In addition to existing data concerning the reinforcing effects of cocaine in DAT-KO mice, these data suggest a dissociation between the reinforcing and locomotor stimulant effects of cocaine.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of medicinal chemistry 37 (1994), S. 2258-2261 
    ISSN: 1520-4804
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of medicinal chemistry 38 (1995), S. 3933-3940 
    ISSN: 1520-4804
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of medicinal chemistry 37 (1994), S. 3875-3877 
    ISSN: 1520-4804
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 109 (1992), S. 241-244 
    ISSN: 1432-2072
    Keywords: Cocaine ; Self administration ; D1 dopamine agonists ; SKF 38393 ; Reinforcement ; Squirrel monkeys
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects of the dopamine receptor D1 partial agonist, SKF 38393, on behavior maintained by cocaine was assessed in squirrel monkeys (Saimiri sciureus). One group of subjects was trained to press a key under a fixed-ratio 30-response schedule of cocaine injection; when green stimulus lamps were illuminated each 30th response produced an injection (17 µg/kg) followed by a 1-min period during which the lights were out and responses had no scheduled consequences. Another group of squirrel monkeys was trained under an identical schedule with food reinforcement. SKF 38393 produced dose-related decreases in rates of responding maintained by either cocaine injection or food presentation. Rates of responding maintained by cocaine were decreased to a greater extent than those maintained by food. The ED50 value for SKF 38393 for responding maintained by cocaine was 2.53 mg/kg (95% CL: 1.22–5.23), whereas that value was 15.63 mg/kg (95% CL: 2.83–86.33) for responding maintained by food. Rates of responding maintained by cocaine were an inverted-U-shaped function of dose. Pretreatment with 3.0 mg/kg SKF 38393 shifted the ascending limb of the cocaine dose-effect curve to the right. These findings suggest that indirect D1-receptor activation plays a role in the reinforcing effects of cocaine, and that drugs acting at D1 receptors may show promise as therapeutic agents in the treatment of cocaine abuse.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 113 (1993), S. 19-25 
    ISSN: 1432-2072
    Keywords: Quinpirole ; SKF 38393 ; SCH 23390 ; Haloperidol ; Spiperone ; Schedule-controlled responding ; Squirrel monkeys
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects on schedule-controlled operant behavior of the D2 receptor agonist, quinpirole, and the D1 agonist, SKF 38393, were assessed alone and in combination with selective dopamine-receptor antagonists. Squirrel monkeys (Saimiri sciureus) were trained to press a response key under fixed-interval and fixed-ratio schedules of food reinforcement. The fixed-interval schedule maintained relatively low rates of responding that increased up to food presentation. The fixed-ratio schedule maintained relatively constant high rates of responding. Quinpirole increased rates and disrupted the temporal pattern of responding under the fixed-interval schedule at doses (0.1–1.0 mg/kg) that decreased rates of responding under the fixed-ratio schedule. Under the fixed-interval schedule, the D2 antagonists, spiperone (0.003–0.006 mg/kg) and haloperidol (0.003–0.01 mg/kg), and the D1 antagonist, SCH 23390 (0.03 mg/kg), shifted the quinpirole dose-effect curve to the right. The maximal effects of quinpirole were decreased at the highest doses of the antagonists. However, only spiperone antagonized effects of quinpirole on the rates of responding under the fixed-ratio schedule. The D1 agonist, SKF 38393, dose-dependently (1.0–10.0 mg/kg) decreased rates of responding under both schedules. Those effects were not antagonized by any doses studied of either spiperone (0.003 mg/kg) or SCH 23390 (0.003–0.3 mg/kg). Rather, both antagonists enhanced the effects of SKF 38393. The present study suggests significant differences between the effects of D1 and D2 agonists on schedule-controlled behavior, and differences in the antagonist actions of the D2 antagonists haloperidol and spiperone. Further, the “selective” dopamine D1 agonist, SKF 38393, has behavioral effects that cannot be antagonized by either a D1 or D2 antagonist, suggesting that some other mechanism has a significant role in mediating its behavioral effects.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 134 (1997), S. 201-212 
    ISSN: 1432-2072
    Keywords: Key words Bupropion ; Cocaine ; Dopamine transporter ; Uptake inhibition ; Antidepressants ; Drug abuse ; Drug discrimination ; D1 receptors ; D2 receptors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Bupropion is a novel, non-tricyclic antidepressant with a primary pharmacological action of monoamine uptake inhibition. The drug resembles a psychostimulant in terms of its neurochemical and behavioural profiles in vivo, but it does not reliably produce stimulant-like effects in humans at clinically prescribed doses. Bupropion binds with modest selectivity to the dopamine transporter, but its behavioural effects have often been attributed to its inhibition of norepinephrine uptake. This experiment examines monoaminergic involvement in the discriminative stimulus effects of bupropion. Rats were trained to press one lever when injected IP with bupropion (17.0 mg/kg), and another lever when injected with saline. In substitution tests, dose-response curves were obtained for several monoamine uptake inhibitors. Nine of ten dopamine uptake blockers fully substituted for bupropion; the exception, indatraline (LU 19-005), partially substituted (71% bupropion-appropriate responding). Serotonin and norepinephrine uptake blockers (zimelidine and nisoxetine, respectively) produced negligible or limited substitution, and the anti-muscarinic dopamine uptake blocker benztropine produced limited partial substitution. A series of dopamine D1-like and D2-like receptor agonists were also tested: only the D2-like agonist RU 24213 fully substituted; three other D2-like agonists and four D1-like agonists partially substituted (50% 〈 drug responding 〈 80%). Antagonism of the discriminative effects of bupropion was obtained with a D1- and a D2-like dopamine antagonist. The results demonstrate strong similarities with those obtained using other dopamine uptake inhibitors as training drugs, and support the view that the behavioural effects of bupropion are primarily mediated by dopaminergic mechanisms.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 87 (1985), S. 272-277 
    ISSN: 1432-2072
    Keywords: N6-(phenylisopropyl)-adenosine ; Caffeine ; Schedule-controlled responding ; Fixed-interval schedule ; Fixed-ratio schedule
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Effects of the (-)- and (+)-isomers of N6-(phenylisopropyl)-adenosine (PIA) were studied in rats trained to respond under fixed-interval and fixed-ratio schedules of food reinforcement. Both isomers of PIA decreased response rates; however, the (-)-isomer decreased response rates at doses as low as 0.1 μM/kg and was 100–300 times more potent than the (+)-isomer. The potency differences suggest that the effects observed were due to actions at A1-adenosine receptors. Caffeine, an adenosine-receptor antagonist, when administered alone in doses of 10–154 μM/kg, increased response rates under the fixed-interval schedule and did not affect rates of responding under the fixed-ratio schedule. Higher doses decreased response rates under both schedules. Caffeine shifted the (-)-PIA dose-effect curve to the right. At a low dose of caffeine (25.7 μM/kg), which alone modestly increased response rates under the 5-min fixed-interval schedule, the disruptions in rates and patterns of responding produced by (-)-PIA were restored to resemble control performances. The higher dose of caffeine (77.2 μM/kg), which alone produced larger increases in rates of responding under the fixed-interval schedule, restored overall response rates to control levels when administered in combination with (-)-PIA. However, patterns of responding after the combination of doses remained disrupted. These effects suggest that some of the behavioral effects of caffeine are a result of mechanisms other than adenosine-receptor blockade.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 88 (1986), S. 392-397 
    ISSN: 1432-2072
    Keywords: Opioid withdrawal ; Morphine ; Clonidine ; Naloxone ; Rhesus monkeys
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rhesus monkeys undergoing opioid withdrawal either due to withholding morphine administration for 14 h or due to administration of naloxone, were treated with either morphine or clonidine. Morphine eliminated all of the withdrawal signs that developed when morphine was withheld for 14 h. Clonidine also eliminated some but not all signs that developed when morphine was withheld. The frequencies of individual signs prior to drug administration were directly related to the minimal doses necessary to eliminate signs for morphine but not for clonidine. Morphine also eliminated most of the signs precipitated by naloxone, whereas clonidine did not eliminate as many of the naloxone-precipitated signs. Additionally, some of the naloxone-precipitated signs that were eliminated by clonidine were not eliminated by morphine. The present results are consistent with clinical findings indicating an efficacy of clonidine in the treatment of opioid withdrawal through a non-opioid mechanism.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 90 (1986), S. 461-467 
    ISSN: 1432-2072
    Keywords: Histamine ; H1 antagonists ; Chlordiazepoxide ; Punished responding ; Squirrel monkeys
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Squirrel monkeys were trained to press a key under a two-component schedule of food presentation. In the presence of either green or red stimulus lights, the 30th response produced a food pellet (fixed-ratio schedule). During the red stimulus lights (punishment component), the first response of each fixed ratio produced either an IV injection of histamine (100.0 μg/kg/inj) or a brief electric shock (3.0 mA). Responding was selectively suppressed in either punishment component. Presession IM administration of chlorpheniramine (0.1 and 0.3 mg/kg), diphenhydramine (1.0 and 3.0 mg/kg), or pyrilamine (0.1 and 0.3 mg/kg) increased rates of responding punished by histamine but not those punished by electric shock. Presession administration of promethazine (0.1–3.0 mg/kg) or tripelennamine (0.1 and 0.3 mg/kg) also increased rates of responding punished by histamine in all subjects and response rates punished by electric shock in one of three subjects. Chlordiazepoxide (3.0–56.0 mg/kg) increased rates of responding punished by either histamine or electric shock. These results suggest that the punishing effects of histamine injection are mediated by H1 receptors and that H1-receptor antagonists increase rates of responding suppressed by punishment only under limited conditions including those in which histamine is the punishing stimulus.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...