Anna Fundaro

Action of a chronic arecoline administration on mouse motility and on acetylcholine concentrations in the CNS.

Abstract— The modifications of mouse motility and of the levels of acetylcholine (ACh) in two sections of the CNS caused by a chronic administration of 4.5; 9.5; 28.5 and 60 mg kg‐−1 day−1 of arecoline for 20 days have been studied. At low doses (4.5 and 9.5 mg kg−1 day−1), arecoline caused no modification of the ACh levels and of the motility. The higher doses (28.5 and 60 mg kg−1 day−1) caused a reduction of the mouse motility and an increase of the ACh levels in the subcortical structures of the CNS of the mouse.

Pinch-induced catalepsy in mice : A useful model to investigate antidepressant or anxiolytic drugs

1. Repeated pinching at the scruff produces, in experimental test/retest sessions, prolonged cataleptic-like immobility in mice that may mimic immobilities seen in some natural situations. 2. In the first experiment, on male mice, imipramine and amitriptiline (20 and 30 mg/kg i.p.) augmented the number of pinches necessary to reach the criterion of induced catalepsy and reduced the total time of catalepsy. 3. In the second experiment, on female mice, compounds that modulate the central 5-HT transmission, like fluvoxamine, fluoxetine (20 mg/kg i.p.) and ondansetron (0.1 and 1 mg/kg i.p.), retarded the occurrence and shortened the duration of pinch induced catalepsy at doses that did not modify the open field performances. Maprotiline (a selective inhibitor of the NA reuptake) did not modify the mices performances in respect to controls. 4. Female mice presented a more rapid occurrence and a prolonged duration of pinch-induced catalepsy in respect to male controls. The present behavioral test may become a simple experimental model to detect new antidepressant or anxiolytic compounds and the significant sex difference could make the test a more useful tool in investigating anxiety behaviour in rodents.

The effect of chronic atropine administration on mouse motility and on ACh levels in the central nervous system.

Changes in mouse motility and CNS cortical and subcortical ACh levels were studied after chronic (20 days) administration of 30, 40 and 60 mg/kg/day atropine. An increase in motility similar to that induced by acute atropine administration was observed, whereas the ACh levels reduction caused by acute administration was not repeated. These results suggest that changes in mouse motility caused by atropine are not correlated to its modification of ACh levels in the CNS.

Action of 5-hydroxytryptamine, histamine and methergoline on phagocytosis.

Polymorphonuclear leukocytes of guinea pig were used to study the action of 5-hydroxytryptamine, histamine and methergoline on phagocytosis. Phagocytosis was reduced by 5-HT; this effect was only in p

Behavioural effects of chronic administration of nimodipine in grouped or individually housed rats

Abstract 1. 1. Behavioural experiments were carried out on grouped or individually housed rats, which assumed a daily dose of nimodipine (around 30 mg/kg/day). 2. 2. Two operant tests plus an open field session were made. In the “periodic conditioning” test, the schedule of reinforcement was changed from a fixed ratio to a fixed interval schedule. In the “reversal” test the contingency for food delivery was switched four times from one lever to the other in a two lever Skinner box. 3. 3. In the “periodic conditioning” test, nimodipine treatment did not cause significant modifications in grouped rats. Isolated controls showed a depressed performance, which was overcome by nimodipine treatment. 4. 4. In the “reversal” test nimodipine treatment seemed to improve the cognitive performances of grouped and isolated rats. No differences were found between experimental groups in “open field” test.

Chronic nimodipine and yawning behaviour in grouped or individually housed rats

1. The effects of a chronic administration (around 30 mg/ kg/day) of the dihydropyridine calcium antagonist nimodipine, on apomorphine induced yawning behaviour of grouped or individual housed rats, were studied. 2. Nimodipine treatment had no effect in grouped rats. 3. Individually housed animals gave a significant lower number of yawns in respect to grouped controls: this difference disappeared in isolated, nimodipine treated, group. 4. The results show the ability of nimodipine to restore a depressed behavioural performance.