Induction of rotational behaviour by intranigral baclofen suggests possible GABA-agonist activity

Summary In rats, unilateral injections of the GABA-derivative baclofen into the zona reticulata of the substantia nigra produced a contralateral rotation that was translated to ipsilateral rotation under the influence of amphetamine. These results mimic those following unilateral elevation of GABA levels in the substantia nigra and suggest that baclofen may have some GABA agonist activity following intracerebral injection.Baclofen was a generous gift of Ciba-Geigy Ltd.J. L. W. is a Medical Research Council Scholar.     

In vivo continuous electrochemical determination of dopamine release in rat neostriatum]

Polarographic micro-electrodes (carbon fiber, o. d. 8 micron) implanted in the Rat caudate nucleus, allowed a practically continuous in vivo monitoring (one measurement every 5 sec.) of the extra-cellular concentration of dopamine released by striatal dopaminergic terminals. Administration of amphetamine produced a reproducible increase of the oxidation current. This effect was suppressed after the selective degeneration of the striatal dopaminergic terminals following the injection of 6-OHDA into the substantia nigra or after inhibition of the synthesis of the amine by alpha methyl-p-tyrosin. After 5 hrs. this drug produced a 70% decrease of the oxidation current.     

Behavior modifications induced by unilateral administration of picrotoxin into rat substantia nigra]

Intranigral injection of picrotoxin in Rats induced contralateral rotation and stereotyped behaviour. These responses were significantly altered following neuroleptic treatment (haloperiod, pimozide) or ipsilateral striatal electrolytic destruction. The present results provide behavioural evidence for gamma-aminobutyric acid-mediated inhibition of the dopaminergic nigrostriatal pathway.     

Der Einfluss verschiedener Psychopharmaka auf den Bluthistamingehalt von Ratten

Summary The concentration of histamine in plasma of rats is changed by injection of psychopharmacons as follows: decreased by narcotics (ether, chloroform) and phantastics (LSD, mescaline), increased by tranquilizers (reserpine, chlorpromazine) a hypnotic (numal) and psychotomimetics (iproniacide, amphetamine).     

Effect of ethanol on toxicity and metabolism of amphetamine in the mouse.

Ethanol, 3 g/kg i.p., did not significantly alter the acute toxicity of amphetamine in the mouse. However, the urinary metabolite pattern was changed, suggesting that ethanol suppressed metabolism of the stimulant during the initial 6 h period. After 24 h, the mouse metabolized the same fraction of a given dose of amphetamine, whether it was given as amphetamine alone or amphetamine mixed with 2,3 or 4 g/kg ethanol.     

Reduced tuberoinfundibular dopaminergic neuronal function in rats after long-term withdrawal of estrogen treatment

Summary Hypothalamic fragments from female rats treated repeatedly with estradiol valerate (EV) and bearing prolactin (PRL)-secreting tumors contained, seven months after the last EV injection, lower concentrations of dopamine (DA) than age-matched controls. Depolarizing concentrations of K⁺ (35 mM) and amphetamine (50 M) evoked in PRL-secreting tumor bearing rats an endogenous DA release significantly lower than in controls.     

The C-terminal tetrapeptide of cholecystokinin decreases hunger in rats

Summary Intraperitoneal injection of the C-terminal tetrapeptide amide of cholecystokinin (CCK) suppressed feeding behaviour and food intake in rats deprived of food for 12 h in a dose-dependent manner. The CCK-4 possesses a hunger suppressive property similar to the full molecule of CCK.     

Pseudolymphoma of skin induced by oriental hornet (Vespa orientalis) venom.

Intradermal injection of saline suspension of Vespa orientalis venom sac to 57 black mice caused a local nodule composed of lymphocytes, few histiocytes and plasma cells 10 to 12 days following the injection. This reaction simulates the pseudolymphoma reaction observed in humans following arthropode stings.     

Reconsideration of a test for dopaminergic stimulation: inability of apomorphine to induce mouse jumping

Apomorphine was administered parenterally to mice in an unsuccessful attempt to induce amphetamine and L-3,4-dihydroxyphenylalanine-like elicited jumping. The efficacy of jumping behavior as an indicator of dopaminergic overstimulation is criticized in light of the results.     

Reconsideration of a test for dopaminergic stimulation: Inability of apomorphine to induce mouse jumping

Summary Apomorphine was administered parenterally to mice in an unsuccessful attempt to induce amphetamine and L-3,4-dihydroxyphenylalanine-like elicited jumping. The efficacy of jumping behavior as an indicator of dopaminergic overstimulation is criticized in light of the results.     

Pseudolymphoma of skin induced by oriental hornet (Vespa orientalis) venom

Summary Intradermal injection of saline suspension ofVespa orientalis venom sac to 57 black mice caused a local nodule composed o flymphocytes, few histiocytes and plasma cells 10 to 12 days following the injection. This reaction simulates the pseudolymphoma reaction observed in humans following arthropode stings.     

The cause of the primary asymmetry of germ cell distribution in the gonadal primordia of chick embryo]

The primary asymmetry of the distribution of PGCs in the germinal epithelia of the chick embryo is the result of a numerically unequal distribution of these cells in the left and right vascular networks. A statistical proportionality exists between the increases in the degree of primary asymmetry and those in the degree of asymmetry of distribution in the circulation.     

Versuche zur chemischen GedächtnisÜbertragung von farbdressierten Goldfischen auf undressierte Tiere

Summary 36–48 h after the i.p. injection of a low molecular brain extract prepared from colour-trained goldfishes into naive goldfish, these recipients show positive reactions comparable to those shown by the donors. 12–24 h after the injection, the recipients showed an increased activity. No changes in behaviour have been noticed in the recipients of i.p. injections of low molecular brain material from untrained donor fish.     

A preliminary study on the behaviour and biochemical responses subsequent to the injection of 5,6-dihydroxytryptamine into the substantia nigra of the rat.

Injection of 5,7-dihydroxytryptamine into the substantia nigra of rats produces an increase of dopamine in the ipsilateral striatum, and when these animals are injected with amphetamine they do not exhibit any rotation. The mode of action of this neurotoxin is compared with that of 6-hydroxydopamine.     

A preliminary study on the behaviour and biochemical responses subsequent to the injection of 5,6-dihydroxy-tryptamine into the substantia nigra of the rat

Summary Injection of 5,7-dihydroxytryptamine into the substantia nigra of rats produces an increase of dopamine in the ipsilateral striatum, and when these animals are injected with amphetamine they do not exhibit any rotation. The mode of action of this neurotoxin is compared with that of 6-hydroxydopamine.     

On the mechanism of the amphetamine induced vasodilatation at the rat's cerebral cortex

Summary Cerebral cortical blood flow was measured with the hydrogen clearance technique. It was found that the increase in CoBF induced by amphetamine is blocked by atropine or chlorpromazine.This work was supported by grants from Consejo Nacional de Investigaciones Cientificas y Tecnicas and Consejo de Investigaciones de la Provincia de Santa Fé, Argentina.     

Comparison of the morphogenic effects of JH-I and JH-III during the solitary phase of Locusta migratoria]

After injection of oiled solutions of JH-I metamorphosis was much more disturbed than following the same treatment with JH-III. The two hormones reduced in the same way the mortality which occurred after injection of pure peanut oil in the first hours of a larval stage. JH-1 and JH-III seemed to have the same effect on the two phases of Locusta.     

Amphetamine induced turning behavior as an index of stroke in the mongolian gerbil

Summary The effects of i.p. injections of amphetamine and apomorphine were determined before and after unilateral ligation of the carotid artery in the gerbil. Significant increases in turning behavior were observed in the absence of neurohistological evidence of infarction.     

Statistical study of the primary asymmetry in primordial germ cells distribution in the chick embryo]

Statistical analysis of quantitative data obtained from a population of 493 chick embryos shows that the degree of primary asymmetry of PGC distribution in favour of the left side of the embryo is highly significant. Our previously published kinetic interpretation of the same data is confirmed and the origin of the primary asymmetry is discussed.     

Transfer and isolation effects on the feeding behaviour of the angelfish,Pterophyllum scalare

The feeding behaviour of juvenile angelfish (Pterophyllum scalare) has been used as an indicator of their recovery following handling and transfer to a new environment, both with and without conspecifics. Isolated specimens fed less readily than group-housed fish, or those transferred to the test aquaria in groups of three or five, and continued to do so for at least ten days following isolation. Feeding rank-order frequently changed following isolation, suggesting that better foragers may not take the greatest risks in isolation.