D-cycloserine inhibits the development and the expression of locomotor sensitization to amphetamine in rats

Amphetamine use is now an epidemic of global proportions; however, no approved medications are available to treat amphetamine abusers. Since glutamate plays a crucial role in regulating the development and expression of addictive behaviors, such as sensitization, in the present study we examined the possible effect of D-cycloserine, a partial agonist at the glycine site of N-methyl-D-aspartate receptors, on the development and expression of locomotor sensitization to amphetamine. Rats were intraperitoneally injected with saline or D-cycloserine (6 mg/kg), before saline or amphetamine (1.5 mg/kg), on days 1–10. Three days after ceasing the chronic treatment, a challenge test was run. The animals received saline or 6 mg/kg D-cycloserine and, 1 h later, they received 0.75 or 1.5 mg/kg amphetamine; motility was recorded for 2 h. The chronic treatment with D-cycloserine alone had no influence on the acute behavioral response to amphetamine. However, D-cycloserine prevented the development and inhibited the expression of amphetamine sensitization; in both cases the D-cycloserine effect was not significantly different as a function of amphetamine challenge dose. As behavioral sensitization is proposed to model the enhanced ‘drug wanting’ observed in psychostimulant abusers, the present data suggest that D-cycloserine might be a useful therapeutic approach to its treatment

SINGLE AND REPEATED BACLOFEN TREATMENT ATTENUATES THE DISCRIMINATIVE STIMULUS EFFECTS OF MORPHINE IN RATS

The GABAB agonists block the rewarding properties of opiates. However, the role of GABAB receptors in the discriminative properties of these drugs has received little attention. In this line, the present study was performed to investigate the effects of acute (Experiment 1) and chronic (Experiment 2) pretreatment with baclofen on the discriminative stimulus effects of morphine. Rats were trained to discriminate morphine (5 mg/kg i.p.) from saline under a two-lever fixed-ratio schedule of food reinforcement. Experiment 1: a morphine generalization curve was obtained under standard conditions in control and baclofen (1 and 2 mg/kg i.p.) pretreated animals. Acute baclofen pretreatment attenuated morphine-lever responding and response rate at both doses. Experiment 2: the animals were randomly divided in two groups and a morphine generalization curve was obtained in daily consecutive test sessions before (TEST1) and after (TEST2) chronic saline (Group I) or chronic baclofen (2mg/kg) (Group II) administration. As expected, chronic saline pre-treatment was ineffective, while chronic baclofen pretreatment attenuated the stimulus properties of morphine, without modifying the rate-decreasing effect of the drug. The data support a role for GABAergic neurotransmission in the discriminative effects of opiates and demonstrate that a short-term treatment with baclofen is useful for decreasing the sensitivity to narcotic cue

Rm values and structure activity relationships of benzodiazepines

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Observations sur un foyer de Trichinose humaine en Italie

Les auteurs font connaître l'existence d'un foyer de Trichinose humaine découvert, au mois de septembre 1975, dans la commune de Bagnolo in Piano, à proximité de Reggio Emilia. Quatre-vingt-neuf personnes furent atteintes sans qu'il y eut de décès. Après une vaste et rigoureuse enquête sur le terrain, dans les charcuteries et les boucheries, l’origine de la contamination semble pouvoir être attribuée à la consommation de viande d'un cheval provenant d’un pays d'Europe de l’Est ( Pologne ou Yougoslavie)