Navegando por Palavras-chave "Catalepsy"
Agora exibindo 1 - 4 de 4
Resultados por página
Opções de Ordenação
- ItemSomente MetadadadosDeep brain stimulation of the inferior colliculus: A possible animal model to study paradoxical kinesia observed in some parkinsonian patients?(Elsevier B.V., 2015-02-15) Melo-Thomas, Liana [UNIFESP]; Thomas, Uwe; Universidade Federal de São Paulo (UNIFESP); INEC; Univ Marburg; Thomas RECORDING GmbHThe inferior colliculus (IC) plays an important role in the normal processing of the acoustic message and is also involved in the filtering of acoustic stimuli of aversive nature. the neural substrate of the IC can also influence haloperidol-induced catalepsy. Considering that (i) paradoxical kinesia, observed in some parkinsonian patients, seems to be dependent of their emotional state and (ii) deep brain stimulation (DBS) represents an alternative therapeutic route for the relief of parkinsonian symptoms, the present study investigated the consequence of DBS at the IC on the catalepsy induced by haloperidol in rats. Additionally, we investigated if DBS of the IC can elicit motor responses in anesthetized rats and whether DBS elicits distinct neural firing patterns of activity at the dorsal cortex (DCIC) or central nucleus (CNIC) of the IC. A significant reduction of the catalepsy response was seen in rats previously given haloperidol and receiving DBS at the IC. in addition, electrical stimulation to the ventral part of the CNIC induced immediate motor responses in anesthetized rats. the neuronal spontaneous activity was higher at the ventral part of the CNIC than the dorsal part. DBS to the ventral part but not to the dorsal part of the CNIC increased the spike rate at neurons a few hundred microns away from the stimulation site. It is possible that the IC plays a role in the sensorimotor gating activated by emotional stimuli, and that DBS at the IC can be a promising new animal model to study paradoxical kinesia in rats. (C) 2014 Elsevier B.V. All rights reserved.
- ItemSomente MetadadadosGlutamatergic neurotransmission in the inferior colliculus influences intrastriatal haloperidol-induced catalepsy(Elsevier B.V., 2014-07-15) Medeiros, Priscila [UNIFESP]; Viana, Milena de Barros [UNIFESP]; Silva, Regina Cláudia Barbosa da [UNIFESP]; Tonelli, Luan Castro [UNIFESP]; Melo-Thomas, Liana [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Inst Neurociencias & Comportamento INECThe inferior colliculus (IC) is an important midbrain relay station for the integration of descending and ascending auditory information. in addition, it has also been implicated in the processing of acoustic information of aversive nature, as well as in sensory-motor gating. There is evidence that glutamate-mediated mechanisms at the IC level influence haloperidol-induced catalepsy. the present study investigated the influence of glutamate-mediated mechanisms in the IC on catalepsy induced by intrastriatal microinjection of haloperidol (10 mu g/0.5 mu l). Male Wistar rats received bilateral intracollicular microinjections of the glutamate receptor agonist NMDA (10 or 20 nmol/0.5 mu l), the NMDA receptor antagonists MK-801 (15 or 30 nmol/0.5 mu l) or physiological saline (0.5 mu l), followed by bilateral microinjections of haloperidol (10 mu g/0.5 mu l) or vehicle (0.5 mu l) into the dorso-rostral or ventro-rostral striatum. the catalepsy test was performed positioning both forepaws of the rats on an elevated horizontal wooden bar and recording the time during which the animal remained in this position. the results showed that the administration of physiological saline in the IC followed by the microinjection of haloperidol in the dorso-rostral region of the striatum was not able to induce catalepsy. However, when the bilateral administration of NMDA into the IC was followed by microinjection of haloperidol into the dorso-rostral striatum, catalepsy was observed. the microinjection of haloperidol into the ventro-rostral striatum induced catalepsy, counteracted by previous administration of MK-801 into the IC. These findings suggest that glutamate-mediated mechanisms in the IC can influence the intrastriatal haloperidol-induced catalepsy and that the IC plays an important role as a sensorimotor interface. (C) 2014 Elsevier B.V. All rights reserved.
- ItemAcesso aberto (Open Access)Investigação do papel dos receptores glutamatérgicos do tipo ampa no colículo inferior sobre a catalepsia induzida pelo haloperidol em ratos(Universidade Federal de São Paulo (UNIFESP), 2013-12-16) Tonelli, Luan Castro [UNIFESP]; Santos, Ronaldo Vagner Thomatieli dos [UNIFESP]; Melo, Liana Lins; http://lattes.cnpq.br/9928572887023286; http://lattes.cnpq.br/2108039540261881; Universidade Federal de São Paulo (UNIFESP)O colículo inferior (CI) é uma estrutura mesencefálica primariamente envolvida no processamento da informação auditiva, mas também integra informação sensorial de natureza aversiva. A estimulação elétrica ou química dessa estrutura induz respostas típicas de medo tais como alerta, congelamento e fuga, eliciadas por ameaças ambientais. Evidências científicas sugerem que o substrato neural responsável pelo comportamento defensivo no colículo inferior pode também ser regulado por aminoácidos excitatórios uma vez que a microinjeção de NMDA nessa estrutura induz comportamento defensivo caracterizado por corrida, levantamentos e saltos. Entretanto, a microinjeção de AP7, um antagonista competitivo de receptores NMDA impede a expressão desses comportamentos. Tem sido demonstrado que a estimulação do substrato neural do medo no colículo inferior causa um aumento significante nos níveis extracelulares de dopamina em outras estruturas tais como o córtex frontal. Estudos prévios realizados em nosso laboratório mostram que a microinjeção de antagonistas de receptores glutamatérgicos do tipo NMDA no CI é capaz de reverter a catalepsia induzida pelo haloperidol. Mas ainda não se sabe se os receptores glutamatérgicos do tipo AMPA no CI também podem ser responsáveis por modular o processo de catalepsia. O presente trabalho investigou se a microinjeção de DNQX, um antagonista de receptores glutamatérgicos do tipo AMPA, diretamente no colículo inferior, foi capaz de influenciar a catalepsia induzida pela administração sistêmica do neuroléptico haloperidol. Os animais foram submetidos a uma cirurgia para implantação de uma cânula no CI e receberam microinjeções de DNQX (1,0μg/0,5μl e 2,5μg/0,5μl). Em seguida foi realizada a administração sistêmica de haloperidol (1,0 mg/kg) e imediatamente após, os animais foram colocados em uma arena onde foi realizada a avaliação da catalepsia. Os resultados mostram que a microinjeção de DNQX, um antagonista de receptores AMPA diretamente no colículo inferior na dose de 1,0μg/0,5μl, pode reverter a catalepsia induzida pelo haloperidol.
- ItemSomente MetadadadosL-NOARG-induced catalepsy can be influenced by glutamatergic neurotransmission mediated by NMDA receptors in the inferior colliculus(Elsevier B.V., 2012-10-01) Iacopucci, Ana Paula; Mello, Rodrigo de Oliveira; Silva, Regina Cláudia Barbosa da [UNIFESP]; Melo-Thomas, Liana [UNIFESP]; Inst Neurociencias & Comportamento INEC; Univ Sao Francisco; Universidade Federal de São Paulo (UNIFESP)The inferior colliculus (IC), a midbrain structure that processes acoustic information of aversive nature, is distinguished from other auditory nuclei in the brainstem by its connections with structures of the motor system. Recent evidence relating the IC to motor behavior shows that glutamate-mediated mechanisms in the neural circuits at the IC level modulate haloperidol-induced catalepsy. It has been shown that N-G-nitro-L-arginine (L-NOARG), inhibitor of enzyme nitric oxide synthase (NOS), can induce catalepsy after intraperitoneal (ip), intracerebroventricular or intrastriatal administration. the present study examined whether the catalepsy induced by L-NOARG (ip) can be influenced by collicular glutamatergic mechanisms and if a NO-dependent neural substrate into the IC plays a role in this immobility state. L-NOARG-induced catalepsy was challenged with prior intracollicular microinjections of glutamate NMDA receptor antagonists, AP7 (20 or 40 nmo1/0.5 mu l), or of the NMDA receptor agonist N-methyl-D-aspartate (NMDA, 30 nmo1/0.5 mu l). Catalepsy was evaluated by positioning both forepaws of the rats on an elevated horizontal wooden bar and recording the time for which the animal maintained this position. the results showed that intracollicular microinjection of AP7 previous to systemic injections of L-NOARG (90 mg/kg) significantly attenuated the catalepsy. Conversely, intracollicular microinjection of NMDA increased the time of catalepsy when administered 10 min before systemic L-NOARG (10 or 45 mg/kg). the microinjection of L-NOARG (50 or 100 nmol) directly into the IC was not able to induce catalepsy. These findings suggest that glutamate-mediated mechanisms in the neural circuits of the IC modulate L-NOARG-induced catalepsy and participate in the regulation of motor activity. (C) 2012 Elsevier B.V. All rights reserved.