GLORIA

GEOMAR Library Ocean Research Information Access

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
    Springer
    Psychopharmacology 93 (1987), S. 182-187 
    ISSN: 1432-2072
    Keywords: Nomifensine ; B-HT 920 ; Dopamine receptors ; Conditioning ; Dopamine-mediated behaviours ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Conditioning of behavioural effects produced by two drugs acting differently upon dopaminergic neurotransmission was studied. Nomifensine and the putative dopamine autoreceptor agonist B-HT 920 produce contrasting effects on motility, namely increases in locomotor activity and stereotypies as compared to hypokinesia and ptosis. The administration of each of these drugs (US) was repeatedly associated with well-defined environmental stimuli (CS): a wire cage associated with an auditory and on olfactory stimulus. The rats were conditioned for 7 days with 20 mg/kg nomifensine IP each day. After conditioning, the rats were treated with the solvent alone in presence of the CS. Not only did sniffing and licking occur, but also gnawing, even though the latter response was not evident after acute administration of the drug or during the conditioning period. Nomifensine (20 mg/kg IP) also acutely decreased the ratio of 3,4-dihydroxyphenylacetic acid/dopamine concentrations (DOPAC/DOPAMINE); this ratio was not altered in the conditioned rats, 60 min after solvent administration in presence of the CS. Rats were conditioned with 0.02 mg/kg IP B-HT 920 daily for 8 days. During the conditioning phase, akinesia and ptosis showed a slight enhancement and a faster onset. After conditioning, when the rats were treated with the solvent alone, the majority of them showed akinesia and/or ptosis during the observation period, in contrast to pseudoconditioned controls. When these rats were conditioned or pseudoconditioned, respectively, with B-HT 920 for further 5 days using 0.02 mg/kg again, treatment with the same dose in presence of the CS produced a significant enhancement and acceleration of these signs in conditioned as compared with pseudoconditioned control rats. The results show that stereotypies producd by nomifensine and akinesia and ptosis produced by B-HT 920 can be conditioned and that, in addition, a sign of stereotypies which was not manifest during the conditioning period appeared as conditioned response.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-2072
    Keywords: Apomorphine ; Conditioned dopaminergic activity ; Stereotyped behaviour ; Dopamine autoreceptors ; Dopamine metabolism ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We investigated whether pharmacological effects of the dopamine agonist apomorphine can be conditioned by establishing an association of apomorphine administration with exteroceptive cues. Apomorphine was repeatedly administered and subsequently, the rat was put into a test cage and exposed to an acoustic and an olfactory stimulus (“conditioned rats”). Control animals (“pseudoconditioned” rats) were treated with the same pharmacological schedule of apomorphine not temporally associated with the stimuli. On the test day, both groups were injected with saline and exposed to the stimuli described. The stereotyped behaviour produced by large doses of apomorphine (0.5 or 2.0 mg/kg SC), namely sniffing, licking and gnawing, could be conditioned in a pronounced way. During the conditioning period, a change in the stereotypies was observed with regard to the time-course (earlier occurrence) and to the character of the stereotypies (from sniffing to licking and gnawing), when 0.5 mg/kg apomorphine was used, but not with the dose of 2.0 mg/kg. The conditioned responses showed a relatively uniform distribution during the observation period with some increase towards the end of the observation period. Some signs produced by a low dose of apomorphine (0.07 mg/kg SC), namely hypomotility and ptosis, but not yawning, could also be conditioned, although in a less pronounced way. An intermediate dose of apomorphine (0.18 mg/kg SC) produced both signs observed after large doses and those observed after a small dose, occurring alternatingly. Both types of signs could be conditioned using this dosage. Conditioning did not alter striatal or mesolimbic dopamine turnover. These results suggest that only behavioural signs due to an activation of postsynaptic dopamine receptors, but also some symptoms produced by an activation of dopamine autoreceptors can be conditioned.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-2072
    Keywords: Apomorphine ; Stereotypy ; Environmental influence ; Automatic recording ; Dopamine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The topography of stereotyped behaviour produced by apomorphine in rats was studied by using either a scoring system, based on observation in a wire cage, or by quantification of horizontal and vertical activities, and of the total distances run in an open field, using an automatic recording system. The latter design was combined with a classification of the type of stereotyped behaviour observed during recording. In addition, the reproducibility of the nature of the stereotyped behaviour and its dose-dependence in individual animals was evaluated. In rats observed in a wire cage, apomorphine at lower doses (0.25 or 0.50 mg/kg SC) produced stereotyped sniffing. Increasing the doses led to stereotyped licking and the largest dose (5.00 mg/kg SC) produced predominantly stereotyped gnawing, as was demonstrated graphically. The type of behaviour produced by 2 mg/kg apomorphine in the open field was reproduced well in individuals after a second administration 4 days later. The shift from sniffing to gnawing was observed in most, but not all of the individually classified animals after administration of the largest dose (5 mg/kg). The locomotor part of motility was highest in “sniffing animals” and lower when gnawing occurred. The non-locomotor part of motility was low in “sniffing rats” and increased when licking and gnawing occurred. In some of the animals a characteristic “climbing” behaviour was observed in addition after the larger doses, which did not interfere with sniffing, licking or gnawing. A combination of classification by observation and automatic recording seems the most appropriate way to study the topography of stereotyped behaviour produced by apomorphine.
    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...