Phencyclidine-induced stereotyped behavior and serotonergic syndrome in rat

Phencyclidine (50 mg/kg, i.p.) induced in rats a biphasic response consisting of serotonergic syndrome followed by stereotyped behavior. The initial serotonergic syndrome was significantly reduced by cinanserin (20 mg/kg, i.p.) and cyproheptadine (2.0 mg/kg, i.p.) but not influenced by haloperidol (0.5 mg/kg, i.p.). The later stereotyped behavior was significantly reduced by haloperidol (0.5 mg/kg, i.p.) but not influenced by cinanserin (20 mg/kg, i.p.) or cyproheptadine (2.0 mg/kg, i.p.). A lower dose of phencyclidine (5.0 mg/kg, i.p.) elicited only haloperidol-sensitive stereotyped behavior. These results indicate that serotonergic and dopaminergic mechanisms may mediate the behavioral effects of phencyclidine in rats.     

The influence of caffeine on d-amphetamine- and apomorphine-induced stereotyped behavior

The influence of caffeine on amphetamine- and apomorphine-induced stereotyped behavior in guinea pigs has been investigated. Caffeine potentiated amphetamine- and apomorphine-induced stereotyped behavior. These observations support the concept that a dopamine sensitive adenyl cyclase and cAMP play a role in mediating the effect of dopamine at specific striatal dopamine receptors.     

Factors influencing stereotyped behavior of primates in a zoo

Stereotyped behavior is the uniform repetition of a motor pattern that occurs at a higher frequency than considered typical for a species when observed in a natural environment. Stereotypies may be considered atypical behavior and usually indicate that an animal's psychological welfare is at a suboptimal level. Instantaneous scans at 30-sec intervals during 20-min observation periods were conducted on eight primate species at the St. Louis Zoo to determine frequency of occurrence of stereotyped behavior. Results indicated that many biotic and abiotic factors were related to the frequency of stereotyped behavior by captive primates, although rearing method was more important than present environmental conditions. © 1994 Wiley-Liss, Inc.     

Selective dopaminergic regulation of stereotyped forms of aggressive and defensive behavior

In rabbits the dopaminergic agonists (L-DOPA, apomorphine) induce and control the stereotypic forms of behaviour (thumping, licking and biting) selectively. These forms of behaviour can be used as test-responses for quantitative studies of the neuropsychotropic substances acting on the central dopaminergic synapses, and also for screening the antiparkinsonic agents.     

A single gene encodes multiple neuropeptides mediating a stereotyped behavior

Egg laying in Aplysia is characterized by a stereotyped behavioral array which is mediated by several neuroactive peptides. We have sequenced two genes encoding the A and B peptides thought to initiate the egg-laying process, as well as a gene encoding egg-laying hormone (ELH) which directly mediates the behavioral array. The three genes share 90% sequence homology and are representatives of a small multigene family. Each gene encodes a protein precursor in which the active peptides are flanked by internal cleavage sites providing the potential to generate multiple small peptides. Each of the three genes consists of sequences homologous to A or B peptide as well as ELH. Although these genes share significant nucleotide homology, they have diverged such that different member genes express functionally related but nonoverlapping sets of neuroactive peptides in different tissues.     

Sparse and stereotyped encoding implicates a core glomerulus for ant alarm behavior

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The effect of haloperidol on the performance of stereotyped behavior in sows

Environmentally induced stereotypies in gestating sows were inhibited by haloperidol. This inhibitory effect was stronger in sows that directed stereotyped activities toward objects in the environment than in sows performing self-directed stereotypies. The results indicate that dopamine is involved in the performance of stereotypies in pigs, and that haloperidol seem to impair motivational arousal primarily by reducing the rewarding impact of stereotyped self-stimulation.     

Phencyclidine-induced stereotyped behavior in rats: dose response effects and antagonism by neuroleptics.

Phencyclidine hydrochloride produced a very characteristic and reproducible stereotyped behavioral syndrome in rats. Both the intensity and the duration of the phencyclidine-induced stereotyped behavior are elicited in a dose-dependent manner in the 2–16 mg/kg dose range. The predominant behavior elicited by low doses was repetitive lateral head swaying, while with higher doses circling and backward walking were observed in addition to the head swaying. This behavior was antagonized by the neuroleptic agents chlorpromazine, haloperidol, and pimozide, but not by α- or β-adrenergic blockers. These results indicate that the phencyclidine-induced stereotyped behavior may be mediated by central dopaminergic mechanisms.     

The effect of dimethylaminoethanol (deanol) on amphetamine-induced stereotyped behavior (AISB).

The effect of dimethylaminoethanol (deanol) on amphetamine-induced stereotyped behavior (AISB) in guinea pigs was studied. Deanol had no effect on AISB which suggests that deanol has little if any central cholinergic effect on dopamine related stereotyped behavior. This lack of central cholinergic effect is discussed in relationship to the reported clinical efficacy of deanol in human movement disorders.     

Participation of the globus pallidus in the organization of stereotyped behavior in the cat

Electrical stimulation of the globus pallidus of cats produces a stereotype behaviour like that following the injection of high doses of d,1-amphetamine. This drug enhances pallidal response. On the other hand, pallidal stimulation facilitates formation of amphetamine-induced stereotypy which weakens after bilateral destruction of the globus pallidus. Neuroleptic haloperidol in very low doses abolishes pallidal as well as amphetamine-induced stereotypy. As supposed pallidal stereotypy may be connected with the disturbance of nigro-strio-pallidal relations.     

Different role of various regions of the caudate nucleus in phenamine-induced stereotyped behavior in cats

Electrolytic ablation of the ventral parts of the cat caudate nucleus head results in an increase of frequency and disorganization of the pattern of the stereotype head turnings, induced by large doses of amphetamine. Lesion of the dorsal parts, on the other hand, is attended with a decreased number and limited manifestation of stereotype movements. A similar effect appears following a low frequency electrical stimulation of the nucleus ventral part. The disrupting action of neuroleptic haloperidol on the amphetamine-induced stereotype is weakened in animals with ventral lesions and enhanced in those with dorsal lesions. Due to dopaminergic activity, the amphetamine, apparently, produces a functional unbalance between different zones of the caudate nucleus, which underlies stereotype behaviour.     

The effect of housing and environmental enrichment on stereotyped behavior of adult vervet monkeys (Chlorocebus aethiops)

Little information is available on the response of vervet monkeys to different housing conditions or on the suitability of enrichment devices or methods for vervet monkeys. In this study, the authors evaluated the occurrence of stereotyped behavior in adult vervet monkeys under various conditions of housing and enrichment. The variables included cage size, cage level (upper or lower), enrichment with a foraging log, enrichment with an exercise cage and presence of a mate. The authors first determined the incidence of stereotyped behavior in captive-bred, singly housed adult female and male vervet monkeys. They then exposed monkeys to different housing and enrichment situations and compared the incidence of stereotyped behavior among the monkeys. The authors found that more females than males engaged in stereotyped behavior and that females, on average, engaged in such behavior for longer periods of time than males. Stereotyped behavior was most often associated with a small, single cage. The average amount of observed stereotyped activity in monkeys housed in a small cage was significantly lower when the monkeys had access to either a foraging log or an exercise cage. Stereotyped behavior was also lower in female monkeys that were housed (either with a male or without a male) in a larger cage. The least amount of abnormal behavior was associated with the largest, most complex and enriched housing situation. Males and females housed in cages on the lower level of two-level housing engaged in more stereotyped behavior than did monkeys housed in the upper level, regardless of the presence or type of enrichment provided.     

Influence of sarmesin on some dopamine-related types of behaviour

Summary The present study was undertaken to investigate the effects of sarmesin, an analogue of [Sar¹] angiotensin II (ANG II) where the tyrosine hydroxyl group in position 4 is methylated, on dopamine (DA)-related paradigms: locomotor and exploratory behaviour as well as apomorphine (3 mg/kg, ip)-induced stereotypy in rats. Sarmesin (0.5 and 1 g, icv) significantly decreased ambulation and rearing movements, and blocked the inhibitory effect of ANG II (0.1 g) on both types of activity. Sarmesin induced biphasic effects on apomorphine-induced stereotypy depending on the dose increase (0.5 and 5 g, icv) and decrease (10 g). Moreover, sarmesin (5 g) blocked the inhibitory effect of ANG II (2 g, icv) on apomorphine stereotypy. Taken together, these results suggest that sarmesin might interact with AT₁ and AT₂ receptor subtypes. The results further confirm the statement for ANG II-DA interaction in brain structures involved in these types of behaviour.     

Clonazepam use in pregnancy and the risk of malformations

BACKGROUND: Clonazepam (Klonopin) is a benzodiazepine that has been used widely to treat seizures and conditions such as panic attacks and anxiety disorder. However, the current findings about its use in pregnancy are derived from limited studies of small sample size. Because it is commonly prescribed during pregnancy, more information about its safety is needed. METHODS: The medical records of 28,565 infants were surveyed as part of a hospital-based malformation surveillance program to identify those who had been exposed prenatally to an anticonvulsant, including clonazepam. RESULTS: During a 32-month period, 166 anticonvulsant-exposed infants were identified; 52 had been exposed to clonazepam, 43 as monotherapy. A total of 33 (76.7%) of the monotherapy infants were exposed during the first trimester. One (3.0%) infant had dysmorphic features, growth retardation, and a heart malformation (tetralogy of Fallot). CONCLUSIONS: This study did not observe an increase in major malformations in births exposed to clonazepam monotherapy. However, this study is not large enough to have adequate power to determine whether or not the rate of major malformations is increased in clonazepam-exposed pregnancies. No increase has been identified in three other case series. Although the number of patients in this series was larger than previous reports, continued monitoring of pregnancies is needed to determine whether or not clonazepam is teratogenic.     

Disturbed prolactin responses to dopamine-related substances in patients with acromegaly and hyperprolactinemia

We undertook this study, because conflicting data were reported about the dopaminergic regulation of prolactin (PRL) secretion in patients with acromegaly and hyperprolactinemia. In order to clarify the dopaminergic regulation of PRL secretion in patients with acromegaly and hyperprolactinemia, the effects of nomifensine, a central dopamine agonist, FK 33-824, a centrally antidopaminergically acting agent, and domperidone, a peripheral dopamine antagonist, on plasma PRL in these patients were studied. The results were compared with those observed in normal subjects and hyperprolactinemic patients, with or without a pituitary tumor. Nomifensine did not lower the PRL levels and FK 33-824 did not raise the PRL levels in acromegalic patients. In hyperprolactinemic patients, nomifensine did not lower the PRL levels and FK 33-824 failed to raise the PRL levels. Domperidone did not increase PRL in about a third of acromegalic patients, while TRH increased PRL in the all normoprolactinemic acromegalic patients. These results suggest that in acromegalic patients there may be a disturbance in dopamine related neurotransmission and that such disorders also seem to be present in patients with hyperprolactinemia, with or without a pituitary tumor.