Library

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Articles: DFG German National Licenses  (37)
  • Cell & Developmental Biology  (22)
  • Physics  (7)
  • Organic Chemistry  (5)
  • Morphine  (3)
Source
  • Articles: DFG German National Licenses  (37)
Material
  • 1
    ISSN: 1432-2072
    Keywords: Discriminative stimulus properties ; ICSS detection thresholds ; d-Amphetamine ; Morphine ; Haloperidol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A two-choice discrimination task was used to evaluate the effects of psychoactive drugs on the discriminative stimulus properties of brain self-stimulation in rats. In these experiments, brain stimulation served both as a discriminative stimulus and as a reinforcing stimulus, but the two effects were manipulated separately. Animals were trained to a criterion of 95% correct in choosing between two levers, and when this levels of accuracy was reached, the ability to choose correctly remained stable over an 8-month period. Increasing the current strength of the discriminative stimulus from zero to 100% of the training current produced a graded increase in the number of trials completed on the appropriate lever. The discriminative effects produced by brain stimulation were evaluated pharmacologically by using three prototypical psychoactive drugs in an attempt to change the detection threshold for the discriminative stimulus. Morphine, d-amphetamine, and haloperidol, drugs that reliably alter reinforcement thresholds for brain stimulation, failed to change detection thresholds. These results demonstrated that: (1) brain stimulation produces potent and reliable discriminative effects and (2) the effects of psychoactive drugs on detection thresholds can be dissociated from their effects on reinforcement thresholds for brain stimulation.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-2072
    Keywords: Brain self-stimulation ; Fixed ratio reinforcement ; Morphine ; Naloxone ; Naltrexone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats were implanted with stimulating electrodes aimed either at the medial forebrain bundle-lateral hypothalamus (MFB-LH) or the midbrain-central gray (MID-GG), and were trained to lever-press for brain self-stimulation on a fixed ratio: 15 schedule of reinforcement. The dose-dependent effects of morphine (0.1–3.0 mg/kg), naloxone (0.1–30 mg/kg), and naltrexone (0.1–30 mg/kg) were then determined during 1 h test sessions. Both naloxone and naltrexone decreased the rate of responding in the MFB-LH as well as in the MID-CG. However, decrements in response rates were produced in the MID-CG by both naloxone and naltrexone at one tenth the doses required to produce similar decrements with electrodes in the MFB-LH. Dose-dependent decreases in response rates produced by morphine occurred at the same doses in the two electrode sites. At both sites, the decreases in response rates produced by the highest dose of morphine were antagonized completely by a low dose of naloxone (0.1 mg/kg). At an intermediate dose of naloxone (1.0 mg/kg), antagonism occurred in the MFB-LH but not in the MID-CG. At a high dose of naloxone (10 mg/kg), a depression in lever-pressing occurred at both sites in the morphine-treated animal indicating that the depressive action predominated over antagonism. These data explain the lack of consistency of the effects of naloxone on brain self-stimulation previously reported by different laboratories, and demonstrate that the use of partial reinforcement schedules in a rational approach to the evaluation of opioid effects on brain self-stimulation behavior.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-2072
    Keywords: Fixed interval: 60 s schedule ; Intracranial self-stimulation ; Naloxone ; Morphine ; d-Amphetamine ; Phencyclidine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats were implanted with stimulating electrodes aimed at the medial forebrain bundle-lateral hypothalamus (MFB-LH) and were trained to lever-press for brain self-stimulation on a fixed interval: 60 s schedule of reinforcement. The effects of graded doses of naloxone (0.1–30 mg/kg), morphine (0.3–5.6 mg/kg), naloxone plus morphine,d-amphetamine (0.03–1.0 mg/kg), naloxone plusd-amphetamine, phencyclidine (0.3–5.6 mg/kg), and naloxone plus phencyclidine were tested. Naloxone produced a significant decrease in rates at 30 mg/kg. Naloxone (0.1–1.0 mg/kg) plus morphine blocked the dose-dependent decrease produced by morphine alone. In contrast, naloxone (1.0–10 mg/kg) plusd-amphetamine attenuated the graded increase in response rates produced byd-amphetamine. Naloxone (1.0–10 mg/kg) plus phencyclidine did not reliably change the increase in response rates produced by phencyclidine alone. The use of the fixed interval schedule of brain self-stimulation to study these drug interactions is novel, and further demonstrates that the highly reinforcing aspects of brain stimulation, known to be influenced by dopamine, may also be modulated by the endogenous opiate system.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 65 (1982), S. 1743-1751 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Some benzobarrelenes were studied by photoelectron (PE.) spectroscopy. The results can be interpreted by considering dominant through-space interaction of the π-molecular fragments in a Möbius-fashion, Some chemical features of the substrates are rationalized on the basis of these findings.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 8 (1925), S. 490-500 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The rearrangements of 4′-methoxy-N-methyl- and N-methyl-4′-nitro-diatzoaminobenzene have been studied in 20% acetonitrile/aqueous buffers. The reactions are specifically acid catalyzed and involve pre-equilibrium formation of amine and diazonium salt followed by rate-limiting attack of the diazonium ion at a C-atom (C-coupling) to give the corresponding aminoazo compounds. There is no evidence to suggest that, under the present conditions, mechanisms other than the established Friswell-Green mechanism occur. The traditional two-stage synthesis of aminoazo compounds via isolated diazoamino compounds can therefore be replaced by a one stage process for amines which undergo initial attack at a N-atom by diazonium ion (N-coupling).
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 76 (1993), S. 407-415 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Transport processes in plasticized PVC membranes containing the H+ chromoionophore ETH 5294 and additional tetraphenylborate-type mobile sites were analyzed by employing the potential-step method. Using chronoamperometry, impedance spectroscopy, and UV/VIS absorbance measurements, it is shown that the ionophore behaves as a carrier for protons, when the membranes are immersed between two aqueous solutions. It was possible to document the changes in the concentration profiles of both free ionophores and ionic species in some of the membranes. There is no evidence of proton hopping between the ionophores.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 49 (1930), S. 139-151 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In Trichamoeba sp two types of inclusions are recognized on the basis of reaction to vital dyes and tomethods of osmic and silver impregnation. Globular inclusions, which are stained selectively with neutral red, may be blackened under direct observation by exposure to osmic vapor in hanging-drop preparations and demonstrated by osmic and silver impregnation. Rod-like and granular mitochondria, stainable vitally with Janus green, may be distinguished from the neutral-red globules in preparations stained with a mixture of Janus green and neutral red, and are demonstrated by Regaud's chondriosome method.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 51 (1931), S. 527-543 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A vacuome (‘Golgi apparatus’) consisting of small globular inclusions has been demonstrated in Chlamydomonas sp. These inclusions may be seen in the living, unstained organism; they are stainable vitally with neutral red; they have been stained vitally with neutral red and then blackened with osmic vapor under direct observation, and they have been impregnated by osmic and silver methods without previous treatment with neutral red.The reaction of these inclusions to the iodin test for starch suggests that they may play some rǒle, possibly one of storage, in the cycle of starch metabolism.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 193 (1987), S. 217-224 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The Puerto Rican tree frog, Eleutherodactylus coqui, has internal fertilization and direct development on land. In light of these reproductive adaptations, the events of fertilization and early development were studied. Cytological examination of just-fertilized eggs showed that sperm entry is restricted to about 10% of the surface of these large, yolky eggs, and all nuclear events of the first cell cycle occur near the animal pole. Although the oocytes have cortical granules, a number of polyspermic fertilizations were found. One clutch consisted of eggs with a high frequency of polyspermy and of normal development. This raises the possibility that normal development can occur despite multiple sperm entry, a situation not found in other anuran amphibians. With respect to saline requirements, the sperm and the embryo are similar to those in amphibians with external fertilization and aqueous development. Sperm motility was high in low-tonicity conditions, and the normally terrestrial embryo could develop completely from a fertilized egg to a froglet in a low-tonicity aqueous solution.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...