Most behavioral, physiological and cellular effects of theneurotransmitter dopamine require concomitant activation of both D1 and D2 receptors, a phenomenon referred to as D1/D2 synergism. Since D1 and D2 receptors are located mostly on separate neurons, and since D1/D2 synergism occurs in the absence of action potentials, we have suggested that electrotonic coupling via gap junctions plays an important role in this phenomenon. A major constituent of gap junctions is connexin36 (Cx36), a protein that is abundant in neurons. The role Cx36 in D1/D2 synergism, as manifested behaviorally, was studied here in mice genetically engineered to express normal, reduced, or undetectable amounts of this protein. The results show that D1/D2 synergism and its breakdown were not affected by the presence or absence of Cx36. Unexpectedly, it was observed that the absence of Cx36 leads to resistance to the cataleptic effects of reserpine in a gene dosage-dependent manner.

Because the tripeptide MIF-1 (Pro-Leu-Gly-NH2) is known to attenuate the effects of neuroleptic-induced catalepsy as well as neuroleptic-induced proliferation of dopamine (DA) receptors, we studied the related naturally occurring peptide, Tyr-MIF-1 (Tyr-Pro-Leu-Gly-NH2) for similar properties. Male rats were treated SC for 11 consecutive days with either the DA D1 receptor antagonist SCH 23390 HC1 (0.50 mg/kg per day), the DA D2 receptor antagonist spiperone HCl (0.30 mg/kg per day), or vehicle. Half the rats were cotreated daily with Tyr-MIF-1 (1.0 mg/kg per day). The cataleptic effects of SCH 23390 were not altered by Tyr-MIF-1. Tolerance to SCH 23390-induced catalepsy did not develop during the 11-day treatment, and Tyr-MIF-1 had no effect on SCH 23390-induced catalepsy. However, tolerance developed to spiperone-induced catalepsy, and Tyr-MIF-1 attenuated this development of tolerance (p < 0.001). Locomotor and stereotyped activities of the DA D1 and D2 agonists, SKF 39393 (3.0 mg/kg) and quinpirole (3.0 mg/kg) were not affected by Tyr-MIF-1 after treatment with the DA antagonists was discontinued. Tyr-MIF-1 did not alter the Bmax or Kd for in vitro binding of [3H]SCH 23390 and [3H]spiperone to homogenates of the striatum. These findings indicate that Tyr-MIF-1 is able to selectively affect the development of receptor tolerance to a DA D2 receptor antagonist, and that this effect is unrelated to changes in affinity or numbers of D2 receptors.

Nitric oxide (NO) in brain has been implicated in neuronal regulatory processes and in neuropathologies. Previously we showed that NO modified quinpirole-induced yawning, a behavioral measure of dopamine (DA) Da receptor activation in rats. The aim of this study was to characterize the effect of nitro-L-arginine methyl ester HC1 (NAME) and L-arginine HC1 on reactivity of rats to the DA DI receptor agonist SKF 38393 and DA DI antagonist SCH 23390 in intact and neonatal 6-hydroxydopamine (o-OHDA)-lesioned rats (134 ng of base ICV at 3rd day after birth). L-arginine HC1 (300 mg/kg IP) increased the oral activity response in 6-OHDA-lesioned rats, like SKF 38393, and induced catalepsy in intact control rats, like SCH 23390. In contrast, NAME had no effect on oral activity or catalepsy, but fully attenuated SKF 38393-induced oral activity. These findings indicate that L-arginine HC1 has no apparent effect at the DA DI receptor, but that NAME is effective in attenuating a DA DI agonist induced effect. Consequently NO may be an intracellular second messenger for supersensitized receptors associated with DA DI agonist - induced oral activity.

Orientadora: Profª Drª Marcela Bermúdez Echeverry / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Neurociência e Cognição, 2015. / Estudos tem mostrado que o fator de transcricao FosB/ delta FosB e regulado em resposta ao tratamento cronico com antipsicoticos. Porem, so a regulacao do fator FosB no estriado pode ter uma relevancia funcional nas alteracoes motoras pelos antipsicoticos tipicos e atipicos, uma vez que o gene e expressado na via direta e indireta do estriado. Assim, o objetivo do presente trabalho foi determinar se as alteracoes motoras induzidas pela administracao cronica de haloperidol, olanzapina ou clozapina regulam a expressao do FosB de maneira diferenciada no estriado motor e limbico. Metodos: Camundongos adultos machos C57Bl receberam injecao intraperitoneal agudo, subcronico ou cronico de Haloperidol, Olanzapina ou Clozapina. Tambem foram avaliados os efeitos extrapiramidais. Experimento 1: Administracao subcronica (5 dias) foi estudado com haloperidol 4 mg/Kg, olanzapina 15 mg/Kg ou Clozapina 20 mg/Kg para confirmar o efeito cataleptico. Experimento 2: As alteracoes motoras apos do tratamento cronico (77 dias) foram avaliadas com o teste de catalepsia, campo aberto, rota rod, pole test e vacuous chewing movement, com as mesmas doses do experimento 2. No ultimo experimento a expressao da proteina FosB foi avaliada. Resultados: Experimento 1: Com a administracao subcronica tipicos e atipicos induzem a catalepsia, sendo menor com os atipicos. Experimento 2: O tratamento cronico com os dois grupos de neurolepticos induzem alteracoes motoras. Foi observado aumenta da imobilizacao no teste de catalepsia e no campo aberto, sendo maior no grupo Haloperidol. Tambem foi observado alteracao no rota rod. Los grupos Haloperidol e Olanzapina tiveram aumento da expressao do FosB no estriado dorsal e ventral. Porem, o grupo Olanzapina no mostrou aumento na regiao Core do nucleo accumbens, resultado oposto observado com a Clozapina, onde mostrou aumento da expressao na regiao limbica do estriado, sem ser significativo na parte dorsal. Conclusoes: O padrao da expressao do FosB na regiao Core do nucleo accumbens, pode ser correlacionado com os sintomas parkinsonianos induzidos pelos antipsicoticos atipicos como a Clozapina. Assim, a regiao Core, poder ser inclusa na circuitaria dos nucleos basais para o estudo das alteracoes motoras induzidas pelos antipsicoticos. / Background: Studies have shown that the transcription factor FosB/ÄFosB is upregulated in response to chronic neuroleptic treatment. Moreover, regulation of only the factor FosB in striatum might have functional relevance to the motor side effects by either typical or atypical neuroleptics, once this gene is expressed in striatal direct and indirect pathways. Therefore, the goal of this study was determine whether the motor side effects after chronic administration of haloperidol, olanzapine or clozapine shown differential regulation FosB expression in motor and limbic caudate putamen. Methods: Adult male mice C57Bl received either acute, subchronic, or chronic intraperitoneally injections of haloperidol, olanzapine or clozapine, and extrapyramidal effects were evaluated.. Experiment 1: Subchronic administration (5 days) was studied with haloperidol 4 mg/Kg, Olanzapine 15 mg/Kg and clozapine 20 mg/Kg to confirm a steady cataleptic effect. Experiment 2: the motor side effects after chronic treatment (77 days) was evaluated through the catalepsy test, open field, Rota Rod, pole test and vacuous chewing movements, with same doses that experiment 2. Expression FosB protein in the last experiment was examined. Results: Experiment 1: with subchronic administration both typical and atypical neuroleptics induced cataleptic effect, even though the effect was lower with olanzapine and clozapine Experiment 2: chronic treatment showed motor side effects in both neuroleptics groups, evaluated with catalepsy test, open field, with an increased immobilization time in haloperidol group. Also, an alteration in Rota Rod test was observed with both neuroleptics groups, however, haloperidol group was unique showing increased time in pole test, with a little number of vacuous chewing movements but not significant. Haloperidol and olanzapine groups showed increased FosB protein expression in dorsal and ventral striatum. However, olanzapine group had not expression in the Core region in accumbens nucleus, opposite to clozapine group that showed an enlarged expression in this limbic/motor region, with scarcely expression in dorsal striatum. Conclusions: A unique pattern of regulation of FosB expression in core region, accumbens nucleus, may correlates with parkinsonism effect of the atypical neuroleptics, clozapine. Therefore, core region could be included in the basal ganglia circuit to study motor alterations by neuroleptics.

Au XIXe siècle, la science et le fantastique produisent le même effet chez les gens : en mettant ceux-ci en contact avec des phénomènes inouïs, ils les inscrivent dans un rapport dialectique – entre le connu et l’inconnu – qui doit déboucher sur le non-encore-connu, comme s’ils recelaient la promesse d’une révélation. En effet, à la fois les sciences de l’esprit et le récit fantastique permettent de franchir les frontières entre le moi et l’autre, la vie et la mort, le corps et l’esprit. Explorant autant de domaines inconnus relatifs à l’homme, ils redéfinissent les contours de celui-ci. C’est donc en tant que moyens de savoir que ce mémoire met en relation ces sciences (psychiatrie, psychophysiologie, hypnotisme…) et trois récits fantastiques, « Onuphrius » de Théophile Gautier, « La Mort d’Olivier Bécaille » d’Émile Zola et « L’Homme voilé » de Marcel Schwob, où une crise de catalepsie subie par le héros déclenche le processus dialectique. / In the 19th century, science and the fantastic generated the same effect in people’s minds: by making them encounter incredible phenomena, they place them in a dialectical relation – between what is known and the unknown – which leads to the not-yet-known, as if they were concealing a promise of revelation. Indeed, both sciences of the mind and fantastic narratives enable the crossing of frontiers between the self and the other, life and death, body and mind. Exploring all these unknown territories related to man, they redefine his contours. Therefore, it is as means of knowledge that this dissertation is establishing a link between these sciences (psychiatry, psychophysiology, hypnotism...) and three fantastic narratives, “Onuphrius” by Théophile Gautier, “La Mort d’Olivier Bécaille” by Émile Zola and “L’Homme voilé” by Marcel Schwob, where catalepsy crises trigger the dialectical process.

Au XIXe siècle, la science et le fantastique produisent le même effet chez les gens : en mettant ceux-ci en contact avec des phénomènes inouïs, ils les inscrivent dans un rapport dialectique – entre le connu et l’inconnu – qui doit déboucher sur le non-encore-connu, comme s’ils recelaient la promesse d’une révélation. En effet, à la fois les sciences de l’esprit et le récit fantastique permettent de franchir les frontières entre le moi et l’autre, la vie et la mort, le corps et l’esprit. Explorant autant de domaines inconnus relatifs à l’homme, ils redéfinissent les contours de celui-ci. C’est donc en tant que moyens de savoir que ce mémoire met en relation ces sciences (psychiatrie, psychophysiologie, hypnotisme…) et trois récits fantastiques, « Onuphrius » de Théophile Gautier, « La Mort d’Olivier Bécaille » d’Émile Zola et « L’Homme voilé » de Marcel Schwob, où une crise de catalepsie subie par le héros déclenche le processus dialectique. / In the 19th century, science and the fantastic generated the same effect in people’s minds: by making them encounter incredible phenomena, they place them in a dialectical relation – between what is known and the unknown – which leads to the not-yet-known, as if they were concealing a promise of revelation. Indeed, both sciences of the mind and fantastic narratives enable the crossing of frontiers between the self and the other, life and death, body and mind. Exploring all these unknown territories related to man, they redefine his contours. Therefore, it is as means of knowledge that this dissertation is establishing a link between these sciences (psychiatry, psychophysiology, hypnotism...) and three fantastic narratives, “Onuphrius” by Théophile Gautier, “La Mort d’Olivier Bécaille” by Émile Zola and “L’Homme voilé” by Marcel Schwob, where catalepsy crises trigger the dialectical process.

Nitric acid has been implicated in a variety of physiological functions of the mammalian brain, and in a large number of its pathologies. Recently we have demonstrated that a nitric oxide donor (L-arginine) and a nitric-oxide-synthase-inhibitor (nitro-L-arginine-methyl-ester) modified the response of central al dopamine D 1 and D 3 receptors to some of their agonists. In the present study we demonstrate the modulatory effect of L-arginine, nitro-L-arginine-methyl-ester and molsidomine (another nitric oxide donor) on the reactivity of the central dopamine receptors to specific agonists and antagonists. The agonists tested were SKF-38393, 7-OH-DPAT and quinpirole, and the antagonists - SCH-23390 and haloperidol. They were evaluated in the rat by the following behavioral methods: locomotor activity, locomotor coordination, rearings and cataleptogenic activity (D 2 modulation); grooming time (D 1 activation); yawning (D 3 activation) and ethanol- and phenobarbital-sleeping-time parameters after SKF-38393 or quinpirole pretreatment. Our results suggest that nitro-L-arginine-methyl-ester is effective in modulating the reactivity of the central dopamine receptors D 2, D 1 and D 3, to their agonists and antagonists, and that it is much more effective than L-arginine in regulating the righting reflex after ethanol and phenobarbital, in both female and male mature rats.

In rats lesioned neonatally with 6-hydroxydopamine (6-OHDA), repeated treatment with SKF 38393 (1-phenyl-2,3,4,5-tetrahydro-(1H)-3-benzazepine-7,8-diol), a dopamine D1/D5 receptor agonist, produces robust stereotyped and locomotor activities. The gradual induction of dopamine D1 receptor supersensitivity is known as a priming phenomenon, and this process is thought to underlie not only the appearance of vacuous chewing movements in humans with tardive dyskinesia, but also the onset of motor dyskinesias in l-dihydroxyphenylalanine (l-DOPA)-treated Parkinson's disease patients. The object of the present study was to determine the possible influence of the histaminergic system on dopamine D1 agonist-induced activities. We found that neither imetit (5.0 mg/kg i.p.), a histamine H3 receptor agonist, nor thioperamide (5.0 mg/kg i.p.), a histamine H3 receptor antagonist/inverse agonist, altered the numbers of vacuous chewing movements in non-primed-lesioned rats. However, in dopamine D1 agonist-primed rats, thioperamide alone produced a vacuous chewing movements response (i.e., P < 0.05 vs SKF 38393, 1.0 mg/kg i.p.), but did not modify the SKF 38393 effect. Notably, both imetit and thioperamide-induced catalepsy in both non-primed and primed 6-OHDA-lesioned rats, comparable in magnitude to the effect of the dopamine D1/D5 receptor antagonist SCH 23390 (7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine; 0.5 mg/kg i.p.). Furthermore, in primed animals both imetit and thioperamide intensified SCH 23390-evoked catalepsy. In vivo microdialysis established that neither imetit nor thioperamide altered extraneuronal levels of dopamine and its metabolites in the striatum of 6-OHDA-lesioned rats. On the basis of the present study, we believe that histaminergic systems may augment dyskinesias induced by dopamine receptor agonists, independent of direct actions on dopaminergic neurons.

<p>Anti-psychotic drug (APD) administration can induce movement disorders including tardive dyskinesia (TD), characterized by abnormal movements of the oro-facial region and occasionally the trunk and limbs. The most widely accepted model of TD is the APD-induced vacuous chewing movement (VCM). While the mechanism of induction of TD remains unclear, there are two prevailing hypothesis: oxidative stress and dopamine supersensitivity. Currently available APDs antagonize dopamine D2 receptors (D2R) which can result in excessive dopamine accumulation and oxidation which was demonstrated to induce striatal neurodegeneration and increased oxidative stress. The dopamine supersensitivity hypothesis proposes that APD treatment causes an up-regulation of high affinity D2Rs to compensate for D2R antagonism. Curcumin, a derivative of turmeric, has been demonstrated to affect dopamine levels and hold significant anti-apoptotic potential. Thus, the goal of this study was to investigate curcumin’s potential to prevent haloperidol-induced behavioural and biochemical abnormalities. Four groups of rats were treated daily: control; haloperidol (at 2mg/kg intra-peritoneally); curcumin (at 200mg/kg orally in jello) and curcumin plus haloperidol. VCMs, catalepsy and locomotor activity were assessed. Animals were sacrificed and tissues removed for qPCR, immunoblot, receptor binding, and UPLC assessments. At day14 there was a significant increase in VCMs and catalepsy following haloperidol treatment, which was prevented by curcumin treatment. However, curcumin did not alter locomotor activity. Curcumin was demonstrated to increase the expression of the anti-apoptotic molecule BclXL and to increase striatal D2Rs. These investigations support the potential of curcumin in the prevention of TD and provide insight into the complex pathophysiology of this disorder.</p> / Doctor of Philosophy (Medical Science)