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Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

With its chronic administration in a dose of 100 mg/kg lithium carbonate inhibited shaking of the head induced in mice with 5-hydroxytryptophan (5-HTP). This effect did not differ from the action following a single injection of lithium, when the interval between injection of lithium and of 5-HTP was one hour. With the interval lengthened to 24 hours the frequency of shaking diminished only under the effect of chronic administration. At the 5th, 10th and 21st day of a daily administration lithium failed to produce any effect on the hypothermal action of a reserpine-like agent Po 4-1284, but would reduce the protective action of imipramine in a ptosis test. A single injection of lithium made against the background of a chronic injection of water produced an opposite effect, viz. it significantly reduced the protective action of imipramine in hypothermia, but did not affect it with reference to ptosis. Hence, chronic administration of lithium leads to potentiation in its action of the serotonin-negative and central adreno-negative componets and to extenuating the peripheral adreno-negative component.
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PMID:[Effect of lithium on the central serotonin- and adrenergic processes after its chronic administration]. 108 64

We studied the biochemical and pharmacologic modes of action of piribedil and apomorphine in the rat. Although both drugs have many points in common, they are also different in many of their manifestations. Apomorphine causes high-intensity, short-duration stereotyped behavior; it is distributed within the brain in uneven fashion, the striatum being the area of lowest concentration as measured by fluorometry. Direct stereotactic injection within the dopaminergic mesolimbic system, and particularly the tuberculum olfactorium, produced constant intense responses. All effects of apomorphine can be blocked by pimozide, but propanolol, a beta blocker, only reduces aggression and ferocity, leaving stereotyped behaviors intact. Finally, L-5-HTP tends to reduce aggression, ferocity, and to a lesser extent stereotypy; MIF or piribedil, as well as reserpine, potentiates the stereotyped behaviors induced by apomorphine, whereas L-DOPA usually decreases them. Piribedil, on the other hand, causes low-intensity, long-duration stereotyped behavior. It is distributed within the brain almost uniformly. Most effects of piribedil can be blocked by pimozide, but propanolol blocks only aggression and ferocity, leaving stereotyped behaviors intact. On the other hand, clonidine, an alpha-receptor agonist, blocks stereotyped behaviors induced by piribedil but markedly increases aggression, ferocity, and motor activity. L-5-HTP and L-DOPA have little effect on piribedil-induced manifestations. Reserpine decreases piribedil stereotypy. The main metabolite of piribedil, S 584, had no clear-cut pharmacologic action in our hands at the dosage used. It is concluded that both apomorphine and piribedil produce stereotyped behavior by modifying the physiologic balance between mesolimbic and nigrostriatal dopaminergic systems. The other actions of apomorphine and piribedil upon aggression, ferocity, and motor activity are not always in parallel and depend probably on the fact that piribedil is less specific, affecting also noradrenergic, serotonergic, histaminergic, and/or cholinergic circuits. The usefulness of piribedil against some forms of human tremor and its low-intensity antiakinetic action probably result from this pattern of pharmacologic activity.
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PMID:Apomorphine and piribedil in rats: biochemical and pharmacologic studies. 117 Jul 16

The brain lesion technique was used to destroy the ascending 5-hydroxytryptamine (5-HT) system at its cell bodies in the dorsal and medial raphe nuclei in order to assess the importance of 5-HT for the induction of harmine tremor and its antagonism by the dopaminergic agonists, L-DOPA, apomorphine and d-amphetamine. Lesions of the medial or dorsal raphe nucleus reduced the intensity of harmine tremor. The remaining tremor was generally resistant to further reduction by the dopaminergic agonists. 5-hydroxytryptophan was shown to enhance tremor: this effect was reduced both by the raphe lesions and by treatment with L-DOPA. The data are discussed in terms of the possible relationship between 5-HT and dopamine.
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PMID:The importance of 5-hydroxytryptamine for the induction of harmine tremor and its antagonism by dopaminergic agonists assessed by lesions of the midbrain raphe nuclei. 125 13

Olanzapine (LY170053, 2-methyl-4-(4-methyl-1-piperazinyl)-10H-thieno[2,3-b][1,5] benzodiazepine) is a novel "atypical" antipsychotic agent with 5-hydroxytryptamine2.dopamine D1/D2 antagonist activity and anticholinergic properties. In behavioral studies, olanzapine (1.25-10 mg/kg, p.o.) antagonizes apomorphine-induced climbing behavior in mice, demonstrating that the compound possesses D1/D2 antagonist activity in vivo. Olanzapine (0.3-20 mg/kg, p.o.) antagonizes 5-hydroxytryptophan-induced head twitches in mice at doses much lower than those required to block the climbing response, confirming that in vivo, the compound is a more potent 5-hydroxytryptamine2 antagonist than dopamine antagonist. Olanzapine (2.5-10 mg/kg, p.o.) also antagonized oxotremorine-induced tremor in mice. In a conditioned avoidance paradigm in rats, olanzapine inhibits the avoidance response with an ED50 of 4.7 mg/kg p.o; however, unlike other antipsychotic agents, catalepsy is only observed at much higher doses (ED50 39.4 mg/kg, p.o.). These data would suggest that the compound will be less likely to produce undesirable extrapyramidal symptoms. Unlike "typical" antipsychotics, olanzapine (1.25-5 mg/kg p.o.) increases responding during the conflict component of a modified Geller Seifter test, demonstrating that the compound may also possess anxiolytic activity. In another series of experiments, olanzapine (1.25 mg/kg, i.p.) produced clozapine-appropriate responding in a drug discrimination model in which animals had been trained to discriminate clozapine (5 mg/kg, i.p.) from vehicle. On the basis of these results, it would therefore be predicted that olanzapine will have an atypical profile and will be less likely to induce undesirable extrapyramidal symptoms than currently available drugs.
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PMID:The behavioral pharmacology of olanzapine, a novel "atypical" antipsychotic agent. 135 53

The behaviors induced by the 5-hydroxytryptamine (5-HT) precursor 5-hydroxytryptophan (5-HTP) has been called the "5-HT (serotonin) syndrome." These behaviors and others identified in rat pups were observed following administration of 5-HTP (300 mg/kg, SC) on postnatal (PN) days 3, 14, and 28 and in adult rats. Certain 5-HT syndrome behaviors and other uniquely neonatal behaviors were present in PN3 pups treated with vehicle. 5-HTP-treated PN3 pups showed increased head-shakes, rollovers, vocalizations, and forepaw treading and decreased hindlimb abduction. No 5-HT syndrome or neonatal behaviors were present at PN14 or PN28 or in adults treated with vehicle. 5-HTP administered at PN14 stimulated circling, forepaw treading, and resting tremor; at PN28, stimulated head-shakes and resting tremor; and in adults produced only head-shakes. To determine if prior exposure to 5-HTP affected the sensitivity of 5-HT receptor subtypes, the 5-HT1A agonist (+/-)-8-hydroxy-dipropylaminotetralin (8-OH-DPAT) and the 5-HT2/1C agonist (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) were administered to all rats as adults. 8-OH-DPAT (1 mg/kg, SC) produced flattened body posture unaffected by prior exposure to 5-HTP. Head-shakes induced by DOI (5mg/kg, IP) were decreased by prior exposure to 5-HTP at PN3 and adult, but increased by preexposure at PN28. Thus, serotonergic neural systems are implicated in some behaviors of neonates. The developmental patterns suggest changes in the sensitivity to these systems. Further, lasting changes in 5-HT2/1C receptor sensitivity occur due to exposure to 5-HTP.
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PMID:Behaviors induced by 5-hydroxytryptophan in neonatal, preweaning, postweaning, and adult Sprague-Dawley rats. 140 74

The antiserotonin properties of a series of new ergoline derivatives were investigated in several pharmacological test systems which have been proposed for the characterization of putative antagonists at central and peripheral 5-HT2 receptors. In radioligand binding studies with [3H]ketanserin among the new ergolines only 1-methyl-2-brom-9,10-dihydrolysergic acid-bis(beta-acetoxyethyl)-amide (AWD 52-336) showed high affinity at cortical 5-HT2 receptors (Ki-5.4 nmol/l). In 5-HT-amplified ADP-induced aggregation of human platelets 6-nor-6-propyl-9,10-dihydro ergometrine (AWD 52-227) and 9,10-dihydrolysergic acid-di-ethanol-amide (AWD 52-302) were potent inhibitors of 5-HT response. Comparison of this two in vitro tests demonstrated a significant correlation (r = 0.636; p < 0.05) between the ability of the ergolines to block the 5-HT aggregation mediated by platelet 5-HT2 receptors and their affinity to [3H]ketanserin-labelled binding sites in rat cortical membranes. In the used in vivo tests (tryptamine tremor, 5-HTP-induced head twitches) 1-methyl-9,10-dihydrolysergic acid-bis(beta-acetoxyethyl)-amide (AWD 52-83) and AWD 52-336 were found to antagonize the behavioural responses with comparatively moderate potency. The results suggest, therefore, that AWD 52-83 and AWD 52-336 may be both central and peripheral acting 5-HT2 antagonists, whereas AWD 52-227 and AWD 52-302 seem to be potent blockers at peripheral 5-HT2 receptors. Furthermore, the obtained results allow to reveal structure-activity relationships of ergolines. Substitution in position 1 in the tetracyclic ergoline ring system may be important with respect to the efficacy at central 5-HT2 receptors.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Studies with new ergoline derivatives on the effects of central and peripheral 5-hydroxytryptamine receptors. 147 37

Carbaryl (50-200 mg/kg, p.o.) produced dose-dependent tremors and inhibition of striatal AChE activity. A dose-dependent elevation of striatal 5-HT and 5-HIAA levels was also observed with carbaryl but at the higher doses (100-200 mg/kg p.o.). L-Trp or 5-HTP or haloperidol potentiated the carbaryl-induced tremors. Further, 5-HTP or haloperidol, when administered (i) alone, reduced the ED50 value and increased the duration of carbaryl-induced tremors without affecting the maximum tremorogenic response of rats and (ii) together, did not change any of these measures significantly. Atropine (acetylcholine antagonist) completely blocked the tremors produced by carbaryl in the absence or presence of 5-HTP or haloperidol. Methysergide (5-HT antagonist) and bromocriptine (DA agonist) antagonised the potentiating effect of 5-HTP and haloperidol, respectively, on the carbaryl-induced tremors. Furthermore, bromocriptine antagonised the potentiating effect of 5-HTP on the carbaryl-induced tremor but, methysergide failed to achieve this antagonism in presence of haloperidol. These results indicate that carbaryl-induced tremors primarily involve the activation of central cholinoceptors and that the serotonergic potentiation of carbaryl-induced tremors is possibly mediated through the dopaminergic disinhibition of cholinergic neurons.
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PMID:Interaction of central serotonin and dopamine in the regulation of carbaryl-induced tremor. 169 44

The novel tricyclic antidepressant drug tianeptine had an antidepressant-like effect on a rat model of depression based on the deficit in open field activity observed on the day after 2 h restraint. Thus, when tianeptine (10 mg/kg IP) was given 2 h after the end of the restraint to either untreated rats or to animals previously given 10 mg/kg of the drug per day for 13 days, then the deficit was opposed. Tianeptine, given acutely but not chronically, moderately enhanced the 5-HT1C receptor-dependent hypolocomotor effect of m-chlorophenylpiperazine (mCPP) but did not alter other 5-HT1 receptor subtype-dependent behaviour. Acute but not chronic tianeptine also decreased 5-HT2 receptor-dependent body shakes induced by 5-hydroxytryptophan. Shakes induced by the 5-HT2 agonist 1-(2,5-dimethoxy-4-iodophenyl)-2 aminopropane (DOI) were unaffected. The results are discussed in relation to the possible mechanism of antidepressant action of tianeptine.
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PMID:Effects of tianeptine on stress-induced behavioural deficits and 5-HT dependent behaviour. 183 9

Tianeptine is a novel antidepressant which uniquely facilitates 5-hydroxytryptamine (5-HT) uptake. When given in a dose of 10 mg/kg to rats pretreated with either carbidopa or phenelzine, it markedly reduced the frequency of wet-dog shakes, fore-paw treading, tremor and hind-limb abduction evoked by L-5-hydroxytryptophan (L-5-HTP) given 30 or 60 min later. This effect of tianeptine was opposite to that of paroxetine, a selective 5-HT uptake inhibitor, which greatly increased the 5-HTP-induced behavioural syndrome. In contrast, tianeptine did not affect behaviours elicited by the 5-HT receptor agonists, 5-methoxy-N,N-dimethyltryptamine (5-MeODMT) or (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane hydrochloride (DOI), which are not substrates for the 5-HT uptake process. In spinal animals, tianeptine attenuated an ipsilateral flexor reflex, an effect opposite to that of citalopram, a selective 5-HT uptake inhibitor. These effects of tianeptine are consistent with its ability to increase 5-HT reuptake.
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PMID:The effects of tianeptine on wet-dog shakes, fore-paw treading and a flexor reflex in rats are consistent with enhancement of 5-hydroxytryptamine uptake. 191 78

The effect of central serotonergic stimulation on hippocampal and neocortical electrical activity and behavior was studied in freely moving rats by administering: (a) tranylcypromine followed by tryptophan, (b) fluoxetine followed by 5-hydroxytryptophan, or (c) p-chloroamphetamine alone. In all rats, scopolamine-resistant hippocampal rhythmical slow activity (RSA), thought to be dependent on brain serotonin, maintained its normal relation to behavior, occurring in close correlation with Type 1 behaviors (postural changes, turning of the head, walking). This RSA was generally absent during stereotyped behavior (head weaving, forepaw treading, hindlimb splaying and tremor). Scopolamine-resistant neocortical low-voltage fast activity (LVFA), also though to be dependent on brain serotonin, was present during Type 1 behaviors and also during stereotyped behavior. Most rats that developed a full stereotyped behavior syndrome had behavioral and electrocortical seizures which were associated with a reduction in the amplitude of hippocampal activity. These seizures were suppressed by methysergide or benserazide. Metergoline (and methysergide to a lesser extent) suppressed the stereotypic behaviors of the serotonin syndrome, resulting in a striking increase in the locomotion caused by central serotonergic stimulation. Such locomotion was accompanied by RSA and LVFA. It was concluded that increased serotonergic activity in the CNS causes an increase in motor activity and a correlated increase in scopolamine-resistant hippocampal RSA and scopolamine-resistant neocortical LVFA and suggested that metergoline blocks serotonin receptors mediating stereotyped behaviors, thereby permitting the expression of serotonin-mediated locomotion.
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PMID:The effects of serotonergic stimulation on hippocampal and neocortical slow waves and behavior. 193 39


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