Studies on behavioral and biochemical changes in rats after lesion of midbrain raphé

Behavioral Effect of Selective and Non-selective Lesions of Median Raphe Nucleus in the Rat

“…These results are principally in agreement with those obtained in a previous study by WEISSMAN (1973). However, the results are at variance with the observations that lesions of 5-HT neurons (KOSTOWSKI et al, 1968) and decreased synthesis of 5-HT (JACOBS et al, 1974a) increases motor activity. The reason for this difference is the different recording technique used by us, since the spontaneous activity was recorded in the presence of the researchers in the former and by means of stabilimeter cages in the latter study.…”

“…Serotonergic (5-HT) fibers are one of these systems that are interrupted when the medial forebrain bundle is cut (GROSSMAN, 1971;GROSSMAN and GROSSMAN, 1977) or damaged by electrolytic (ANDEN et al, 1966b) and chemical lesions (GERSON and BALDESSARINI, 1975). The functional significance of 5-HT fibers is not clear, but it has been suggested that they are involved in the regulation of locomotor activity (KOSTOWSKI et al, 1968;ROSERCRANS, 1970;JACOBS et al, 1974a, b;SREBO and LORENS, 1975) and consumption of food and water intake (CLINESCHMIDT , 1973;BREISCH et al, 1976;SALLER and STRICKER, 1976;COSCINA , 1977;SAMANIN et al, 1977).…”

Alterations in Brain 5‐hydroxy‐tryptamine Metabolism During the ‘Withdrawal’ Phase After Chronic Treatment With Diazepam and Bromazepam

“…In contrast, a state of general excitement with increased locomotor activity was noted after pharmacological and neurological manipulations which selectively lowered brain 5-HT (e.g. inhibition of 5-HT synthesis by p-chlorophenylalanine: Sheard, 1969;Brody, 1970) and destroyed 5-hydroxytryptaminergic neurones by electrolytic lesions placed in the mid-brain raphe (Kostowski, Giacalone, Garattini & Valzelli, 1968;Neill, Grant & Grossman, 1972). Recently, it was shown that there is a decrease in brain catecholamine turnover (Rastogi et al, 1976c) (Rastogi et al, 1976b).…”

Efeitos comportamentais da lesão eletrolítica da região do núcleo mediano da rafe como modelo experimental de mania no rato e no camundongo

“…Estes resultados, somados aos dados descritos em diversas publicações feitas por diferentes grupos de pesquisa nos últimos 40 anos sobre os efeitos da lesão do MnR em animais de laboratório (Albinsson, Andersson, Andersson, Vega-Matuszczyk, & Larsson, 1996;Andrade, 1997;Andrade & Graeff, 2001;Arpa & De Andres, 1993;Asin, Wirtshafter, & Fibiger, 1985;Asin, Wirtshafter, & Kent, 1979aFile, Hyde, & MacLeod, 1979;Jacobs, Wise, & Taylor, 1974;Kostowski, Giacalone, Garattini, & Valzelli, 1968;Le, Harding, Juzytsch, Fletcher, & Shaham, 2002;Wirtshafter & Asin, 1983;Wogar, Bradshaw, & Szabadi, 1991) permitiram identificar inúmeras semelhanças entre o quadro comportamental induzido pela lesão do MnR e o conjunto de comportamentos esperados para atribuição de validade de face em modelos animais do episódio maníaco do transtorno bipolar (Einat, 2006;Lyon, 1991). A avaliação da literatura especializada mostra, como veremos a seguir, que existem vários dados que dão embasamento à hipótese do envolvimento do núcleo mediano da rafe na neurofisiologia da mania e justificam a proposição do objetivo do presente trabalho.…”

“…Em síntese, a inativação desta estrutura por diferentes procedimentos induz: a) hiperatividade (Albinsson et al, 1996;Jacobs et al, 1974); b) estereotipia ; c) facilitação no comportamento sexual (Albinsson et al, 1996); d) agressividade e desrespeito à hierarquia social (File et al, 1979); e) impulsividade (Fletcher, 1995;Le et al, 2002) e exposição ao "risco" (Andrade & Graeff, 2001;Andrade et al, 1999); f) alterações na aprendizagem e controle de estímulos (Asin et al, 1979a(Asin et al, , 1980Wirtshafter & Asin, 1983); g) aumento no valor reforçador dos estímulos incondicionados e condicionados (Fletcher, Korth, & Chambers, 1999;Vollrath-Smith et al, 2012;Wogar et al, 1991); h) irritabilidade (Kostowski et al, 1968) e i) diminuição do tempo total de sono (Arpa & De Andres, 1993;Arpa, Padrino, Rodriguez-Albarino, & de Andres, 1998).…”