Serotonin (5-HT) has long been implicated in the pathophysiology of depression and anxiety, and the therapeutic effect of treatments. Several drugs useful in treatment produce either acute or neuroadaptive changes in 5-HT_2C receptor activity, and there has been growing interest in how alterations in the 5-HT_2C receptor might be important in mediating antidepressant and anxiolytic activity. The neuropsychological hypothesis of drug action implies that the clinical effects of medications active in anxiety and depression are best understood through the effects of these agents on the processing of emotional information. Thus far, however, there has been no systematic attempt to identify the role of the 5-HT_2C receptor in drug-induced changes in emotional processing in humans. The current research therefore investigated the effects of drug treatments with 5-HT_2C blocking properties on neural and behavioural responses to emotional information in healthy volunteers. An fMRI study demonstrated that a single dose of mirtazapine, an antidepressant with action at the 5-HT_2C receptor, reduces activation in regions important in emotional processing, such as the amygdala and the fusiform gyrus, to threat-relevant stimuli. A series of behavioural studies utilized drugs acting, at least in part, as 5-HT_2C antagonists and agonists to show that these drugs are able to alter emotional processing, particularly emotional memory. A seven-day administration of mirtazapine was shown to increase the recall of positive versus negative personality characteristics. A single dose of agomelatine, also an antidepressant with putative action at the 5-HT_2C receptor, did not increase slow wave sleep, suggesting, the drug had no effect of 5-HT_2C blockade in the brain. In Chapter 4, agomelatine and mCPP, a 5-HT_2C agonist, also shown to had no significant effect on emotional processing measures, but there was a statistical trend for agomelatine to increase memory for positive stimuli, and for mCPP to increase memory for negative stimuli. These findings suggest that antidepressants may work by altering the bias in emotional processing. Overall, the results of this exploration of the role of the 5-HT_2C receptor in emotional processing have contributed to the understanding of antidepressant treatment, and raise new possibilities for the continuation of study in this field.

O uso de drogas de abuso pode levar a alterações neuroplásticas duradouras no encéfalo, entre elas a sensibilização comportamental (SC), um fenômeno relacionado à dependência. O enriquecimento ambiental (EA) permite estudar a influência do ambiente na resposta a diversas manipulações, entre elas o tratamento com drogas de abuso. O objetivo deste trabalho foi avaliar o efeito do EA sobre a SC ao etanol, e sobre a expressão de proteínas envolvidas nas respostas às drogas de abuso: BDNF, TrkB e Egr-1. Para tanto, camundongos foram expostos ao EA, e então tratados repetidamente com uma dose baixa (1,8 g/kg) de etanol. Outros grupos foram submetidos ao protocolo de SC e posteriormente expostos ao EA. O EA protegeu os animais de desenvolverem a SC ao etanol, bem como promoveu sua reversão. O EA diminuiu os níveis de BDNF no córtex pré-frontal e de TrkB no hipocampo, e aumentou a expressão de Egr-1 no córtex insular. O EA pode ser considerado uma estratégia útil para a reversão dos efeitos da SC, que está associada à fissura e a episódios de recaídas na dependência. / The use of addiction drugs can lead to long-term neuroplastic changes on the brain, such as behavioral sensitization (BS), a phenomenon related to addiction. Environmental enrichment (EE) is a strategy used to study the environmental influence on the response to several manipulations, including the treatment with addiction drugs. The aim of this work was to evaluate the effects of EE on the BS to ethanol and on the expression of proteins related to the response to drugs of abuse, as BDNF, TrkB and Egr-1. Thus, mice were exposed to EE and then repeatedly treated with a low dose (1.8 g/kg) of ethanol. Other group of mice was first submitted to the BS protocol and then exposed to EE. EE protected the mice from developing the BS to ethanol, and promoted its reversion. EE decreased BDNF levels in the prefrontal cortex and TrkB in the hippocampus, and increased Egr-1 expression in the insular cortex. EE can be considered and useful strategy to block BS effects, a phenomenon related to craving and relapse.

Psychostimulant dependence is a major public health issue in many parts of the world associated with a wide range of psychological, medical and social problems. Psychosocial interventions are the mainstay of treatment for psychostimulant problems, although their effectiveness is compromised by poor uptake and compliance. Despite increasing knowledge of the neurobiological consequences of psychostimulant use, no medications to date have been any more successful than placebo in reducing psychostimulant use in dependent patients. Modafinil is a non-amphetamine type psychostimulant that may have potential as an agonist pharmacotherapy for psychostimulant dependence. The aim of this thesis was to examine the safety, efficacy and cost-effectiveness of modafinil 200 mg/day over ten weeks plus a four session brief CBT intervention for methamphetamine and cocaine dependence through two concurrent randomised placebo controlled trials. There were no statistically significant differences between modafinil and placebo in treatment retention, medication adherence, psychostimulant abstinence, psychostimulant craving or severity of psychostimulant dependence. Methamphetamine-dependent subjects tended to provide more illicit psychostimulant negative urine samples while in treatment than those who received placebo. There appeared to be a reduction in self-reported days of psychostimulant use among methamphetamine-dependent subjects who received modafinil compared to placebo, but the effect size was too small to be statistically significant in this sample. The reduction in self-reported psychostimulant use did reach statistical significance in methamphetamine-dependent subjects with no other substance dependence. Uptake of counselling was the most significant predictor of reduced psychostimulant use post treatment, and the addition of counselling improved the cost-effectiveness of modafinil relative to placebo. Modafinil appeared to be safe, well-tolerated, and non-reinforcing in this treatment population. Compared to placebo, there was a significant increase in weight in subjects who completed the 10-week course of treatment, and a significant decrease in systolic blood pressure in methamphetamine-dependent subjects who received modafinil. The results support further trials of modafinil in methamphetamine-dependent patients, although future trials in cocaine-dependent patients from this treatment population were not likely to be viable. Modafinil appeared to be modestly effective in reducing, but not stopping, methamphetamine use in selected patients. Multi-centre trials with larger sample sizes, and measures sensitive enough to detect quantitative changes in psychostimulant use would be needed to confirm the findings. Blood pressure and weight may be important indicators of clinical outcome, and warrant particular attention in future trials, particularly given the cardio-toxicity of both methamphetamine and cocaine. Strategies to enhance medication adherence including a higher dose and counselling adherence are recommended to improve outcomes. Given the predominance of behavioural and psychosocial factors in psychostimulant dependence, it is likely that the role of medications such as modafinil will be as an adjunct to psychosocial therapy.

The controversy surrounding the use of LSD as an adjunct to psychotherapy for alcoholics in Saskatchewan has not been explored by social or medical historians. From 1950 to 1967, Saskatchewan psychiatrists developed new treatments for chronic alcoholism by using LSD on themselves, on volunteers and finally on patients. Despite early success and praise, the use of LSD in psychotherapy was later condemned by the media, the general public, the medical profession and eventually the federal government and was discontinued after being banned in 1967. The reasons for the ban were far-reaching and diverse. LSD was exploited by the counter-culture for "kicks" and was later abandoned by pharmaceutical companies because of the negative reputation lay-professionals and the media had bestowed upon its therapeutic use. As it turned out, legitimate LSD research became too clouded in controversy to survive the 1960s as researchers failed to convince the masses that the drug did not pose a threat to the well-being of society. In many respects, the LSD controversy can be seen as more of a moral panic than a scientific debate. Nevertheless, the LSD controversy provides a unique and much needed look into the history of medicine from a social perspective, illustrating that social values often have more impact on medical research than empirical validity. As recent evidence suggests, the psychotherapeutic potential of LSD -- as developed by Saskatchewan psychiatrists -- has not been forgotten. Indeed, a renewal of interest in LSD research has surfaced in several U.S. states as American psychiatrists are discovering, once again, that LSD can be a valuable psychiatric research tool.

Psychostimulant dependence is a major public health issue in many parts of the world associated with a wide range of psychological, medical and social problems. Psychosocial interventions are the mainstay of treatment for psychostimulant problems, although their effectiveness is compromised by poor uptake and compliance. Despite increasing knowledge of the neurobiological consequences of psychostimulant use, no medications to date have been any more successful than placebo in reducing psychostimulant use in dependent patients. Modafinil is a non-amphetamine type psychostimulant that may have potential as an agonist pharmacotherapy for psychostimulant dependence. The aim of this thesis was to examine the safety, efficacy and cost-effectiveness of modafinil 200 mg/day over ten weeks plus a four session brief CBT intervention for methamphetamine and cocaine dependence through two concurrent randomised placebo controlled trials. There were no statistically significant differences between modafinil and placebo in treatment retention, medication adherence, psychostimulant abstinence, psychostimulant craving or severity of psychostimulant dependence. Methamphetamine-dependent subjects tended to provide more illicit psychostimulant negative urine samples while in treatment than those who received placebo. There appeared to be a reduction in self-reported days of psychostimulant use among methamphetamine-dependent subjects who received modafinil compared to placebo, but the effect size was too small to be statistically significant in this sample. The reduction in self-reported psychostimulant use did reach statistical significance in methamphetamine-dependent subjects with no other substance dependence. Uptake of counselling was the most significant predictor of reduced psychostimulant use post treatment, and the addition of counselling improved the cost-effectiveness of modafinil relative to placebo. Modafinil appeared to be safe, well-tolerated, and non-reinforcing in this treatment population. Compared to placebo, there was a significant increase in weight in subjects who completed the 10-week course of treatment, and a significant decrease in systolic blood pressure in methamphetamine-dependent subjects who received modafinil. The results support further trials of modafinil in methamphetamine-dependent patients, although future trials in cocaine-dependent patients from this treatment population were not likely to be viable. Modafinil appeared to be modestly effective in reducing, but not stopping, methamphetamine use in selected patients. Multi-centre trials with larger sample sizes, and measures sensitive enough to detect quantitative changes in psychostimulant use would be needed to confirm the findings. Blood pressure and weight may be important indicators of clinical outcome, and warrant particular attention in future trials, particularly given the cardio-toxicity of both methamphetamine and cocaine. Strategies to enhance medication adherence including a higher dose and counselling adherence are recommended to improve outcomes. Given the predominance of behavioural and psychosocial factors in psychostimulant dependence, it is likely that the role of medications such as modafinil will be as an adjunct to psychosocial therapy.

Diss. (sammanfattning) Stockholm : Karolinska institutet., 2005. / Härtill 5 uppsatser.

A pesquisa de substâncias biologicamente ativas, advinda principalmente de plantas, tem levado a descoberta de moléculas clinicamente benéficas. A família Amaryllidaceae é conhecida por sintetizar alcalóides biologicamente ativos, principalmente do grupo tetraisoquinolínico. Estudos têm demonstrado que a atividade biológica destes vegetais está relacionada com a presença deste grupo de metabólitos secundários. No Rio Grande do Sul, é encontrado o gênero Hippeastrum, pertencente a família Amaryllidaceae. Neste trabalho, realizou-se a investigação preliminar de alcalóides dos extratos de Hippeastrum papilio, coletada na região serrana do estado. Foram isoladas 12 substâncias, nas quais 9 apresentam carcaterísticas químicas de alcalóides de Amaryllidaceae. Estudos preliminares de CLAE-EM e CG-EM apontam para a existência de alcalóides de núcleos licorina e haemantamina, além de núcleo galantamina, em menor quantidade. Estas análises também mostram a possibilidade de estruturas inéditas. Os extratos enriquecidos em alcalóides de Hippeastrum papilio demonstraram uma grande capacidade de inibição da enzima acetilcolinesterase, pelo método da bioutografia em cromatoplaca. Além disso, foi realizada a análise comportamental do alcalóide montanina, previamente isolada de Hippeastrum vittatum Este alcalóide foi avaliado na tarefa de reconhecimento de objeto, com administração intrahipocampal, testado 24 horas pós-treino (memória de longa duração). Obteve-se curva dose-resposta para o alcalóide, com dose pró-cognitiva estatisticamente significante de 1μg/μl. Esta mesma dose foi avaliada na mesma tarefa para obtenção de curva temporal. Montanina demonstrou atividade pró-cognitiva na mesma tarefa e testada 24 horas pós-treino, em administração imediatamente pós-treino, 180 minutos pós-treino, mas não em 360 min pós-treino. O alcalóide montanina também foi avaliado quanto ao perfil de inibição da enzima acetilcolinesterase, utilizando método de ultravioleta. Obteve-se inibição da enzima em concentrações de 10 μM, 100 μM e 1 mM. Os resultados obtidos neste trabalho apontam para a necessidade de continuação da investigação química de Hippeastrum papilio, motivada pelo grande potencial de inibição da enzima acetilcolinesterase e por possibilidade de isolamento de estruturas inéditas. Além disso, foi confirmado um grande potencial pró-cognitivo do alcalóide montanina, demonstrado comportamentalmente, além de inibir a enzima acetilcolinesterase, atividade esta necessária e importante para que uma substância seja candidata à terapia da Doença de Alzheimer. / A search for biologically active substances in plants has led to the discovery of clinically beneficial molecules. The family Amaryllidaceae is known to synthesize biologically active alkaloids, principally of the tetraisoquinolinic group. Studies have shown that the biological activity of these plants is due to the presence of these secondary metabolites. The Hippeastrum genus, belonging to the Amaryllidaceae family, is found in Rio Grande do Sul. A preliminary investigation of alkaloids from extracts of Hippeastrum papilio, collected in the mountain region of the Rio Grande do Sul was done in this work. Twelve substances were isolated, in which nine have chemical profile of Amaryllidaceae alkaloids. Preliminary studies with HPLC-MS and GC-MS showed the existence of lycorine and haemantamine type alkaloids, as well as galantamine type alkaloids in a lower quantity. These analysis also showed a possibile presence of unknown structures. The extracts, enriched in alkaloids of Hippeastrum papilio, demonstrated a great ability to inhibit the acetylcholinesterase enzyme by a rapid thin layer chromatography bioautographic method. Furthermore, it was done a behavior analysis of montanine, previously isolated from Hippeastrum vittatum This alkaloid was evaluated in recognition object task with intrahippocampal administration and tested for 24 hours postrainig (long term memory). There was found a doseeffect curve of montanine with cognitive-enhanced dose at 1μg/μl. This dose was evaluated in the same task for temporal-curve. Montanine showed procognitive activity in immediately postraining administration and 180 minutes postraining but not with 360 min postraining in the same task. The acetylcholinesterase inhibition profile of montanine alkaloid was also evaluated by a ultraviolet method. The enzyme was inhibited in concentrations of 10 μM, 100 μM and 1 mM of montanine. The results obtained in the present study show a need for further chemical investigation on Hippeastrum papilio due to its large potential for inhibition of the acetylcholinesterase and isolation of potentially new structures. Moreover, these results confirm the great pro-cognitive potential of montanine, behaviorally demonstrated, as well as its ability to inhibit the acetylcholinesterase enzime, which makes the alkaloid a candidate substance for the treatment of Alzheimer's Disease.

A pesquisa de substâncias biologicamente ativas, advinda principalmente de plantas, tem levado a descoberta de moléculas clinicamente benéficas. A família Amaryllidaceae é conhecida por sintetizar alcalóides biologicamente ativos, principalmente do grupo tetraisoquinolínico. Estudos têm demonstrado que a atividade biológica destes vegetais está relacionada com a presença deste grupo de metabólitos secundários. No Rio Grande do Sul, é encontrado o gênero Hippeastrum, pertencente a família Amaryllidaceae. Neste trabalho, realizou-se a investigação preliminar de alcalóides dos extratos de Hippeastrum papilio, coletada na região serrana do estado. Foram isoladas 12 substâncias, nas quais 9 apresentam carcaterísticas químicas de alcalóides de Amaryllidaceae. Estudos preliminares de CLAE-EM e CG-EM apontam para a existência de alcalóides de núcleos licorina e haemantamina, além de núcleo galantamina, em menor quantidade. Estas análises também mostram a possibilidade de estruturas inéditas. Os extratos enriquecidos em alcalóides de Hippeastrum papilio demonstraram uma grande capacidade de inibição da enzima acetilcolinesterase, pelo método da bioutografia em cromatoplaca. Além disso, foi realizada a análise comportamental do alcalóide montanina, previamente isolada de Hippeastrum vittatum Este alcalóide foi avaliado na tarefa de reconhecimento de objeto, com administração intrahipocampal, testado 24 horas pós-treino (memória de longa duração). Obteve-se curva dose-resposta para o alcalóide, com dose pró-cognitiva estatisticamente significante de 1μg/μl. Esta mesma dose foi avaliada na mesma tarefa para obtenção de curva temporal. Montanina demonstrou atividade pró-cognitiva na mesma tarefa e testada 24 horas pós-treino, em administração imediatamente pós-treino, 180 minutos pós-treino, mas não em 360 min pós-treino. O alcalóide montanina também foi avaliado quanto ao perfil de inibição da enzima acetilcolinesterase, utilizando método de ultravioleta. Obteve-se inibição da enzima em concentrações de 10 μM, 100 μM e 1 mM. Os resultados obtidos neste trabalho apontam para a necessidade de continuação da investigação química de Hippeastrum papilio, motivada pelo grande potencial de inibição da enzima acetilcolinesterase e por possibilidade de isolamento de estruturas inéditas. Além disso, foi confirmado um grande potencial pró-cognitivo do alcalóide montanina, demonstrado comportamentalmente, além de inibir a enzima acetilcolinesterase, atividade esta necessária e importante para que uma substância seja candidata à terapia da Doença de Alzheimer. / A search for biologically active substances in plants has led to the discovery of clinically beneficial molecules. The family Amaryllidaceae is known to synthesize biologically active alkaloids, principally of the tetraisoquinolinic group. Studies have shown that the biological activity of these plants is due to the presence of these secondary metabolites. The Hippeastrum genus, belonging to the Amaryllidaceae family, is found in Rio Grande do Sul. A preliminary investigation of alkaloids from extracts of Hippeastrum papilio, collected in the mountain region of the Rio Grande do Sul was done in this work. Twelve substances were isolated, in which nine have chemical profile of Amaryllidaceae alkaloids. Preliminary studies with HPLC-MS and GC-MS showed the existence of lycorine and haemantamine type alkaloids, as well as galantamine type alkaloids in a lower quantity. These analysis also showed a possibile presence of unknown structures. The extracts, enriched in alkaloids of Hippeastrum papilio, demonstrated a great ability to inhibit the acetylcholinesterase enzyme by a rapid thin layer chromatography bioautographic method. Furthermore, it was done a behavior analysis of montanine, previously isolated from Hippeastrum vittatum This alkaloid was evaluated in recognition object task with intrahippocampal administration and tested for 24 hours postrainig (long term memory). There was found a doseeffect curve of montanine with cognitive-enhanced dose at 1μg/μl. This dose was evaluated in the same task for temporal-curve. Montanine showed procognitive activity in immediately postraining administration and 180 minutes postraining but not with 360 min postraining in the same task. The acetylcholinesterase inhibition profile of montanine alkaloid was also evaluated by a ultraviolet method. The enzyme was inhibited in concentrations of 10 μM, 100 μM and 1 mM of montanine. The results obtained in the present study show a need for further chemical investigation on Hippeastrum papilio due to its large potential for inhibition of the acetylcholinesterase and isolation of potentially new structures. Moreover, these results confirm the great pro-cognitive potential of montanine, behaviorally demonstrated, as well as its ability to inhibit the acetylcholinesterase enzime, which makes the alkaloid a candidate substance for the treatment of Alzheimer's Disease.

O uso de drogas de abuso pode levar a alterações neuroplásticas duradouras no encéfalo, entre elas a sensibilização comportamental (SC), um fenômeno relacionado à dependência. O enriquecimento ambiental (EA) permite estudar a influência do ambiente na resposta a diversas manipulações, entre elas o tratamento com drogas de abuso. O objetivo deste trabalho foi avaliar o efeito do EA sobre a SC ao etanol, e sobre a expressão de proteínas envolvidas nas respostas às drogas de abuso: BDNF, TrkB e Egr-1. Para tanto, camundongos foram expostos ao EA, e então tratados repetidamente com uma dose baixa (1,8 g/kg) de etanol. Outros grupos foram submetidos ao protocolo de SC e posteriormente expostos ao EA. O EA protegeu os animais de desenvolverem a SC ao etanol, bem como promoveu sua reversão. O EA diminuiu os níveis de BDNF no córtex pré-frontal e de TrkB no hipocampo, e aumentou a expressão de Egr-1 no córtex insular. O EA pode ser considerado uma estratégia útil para a reversão dos efeitos da SC, que está associada à fissura e a episódios de recaídas na dependência. / The use of addiction drugs can lead to long-term neuroplastic changes on the brain, such as behavioral sensitization (BS), a phenomenon related to addiction. Environmental enrichment (EE) is a strategy used to study the environmental influence on the response to several manipulations, including the treatment with addiction drugs. The aim of this work was to evaluate the effects of EE on the BS to ethanol and on the expression of proteins related to the response to drugs of abuse, as BDNF, TrkB and Egr-1. Thus, mice were exposed to EE and then repeatedly treated with a low dose (1.8 g/kg) of ethanol. Other group of mice was first submitted to the BS protocol and then exposed to EE. EE protected the mice from developing the BS to ethanol, and promoted its reversion. EE decreased BDNF levels in the prefrontal cortex and TrkB in the hippocampus, and increased Egr-1 expression in the insular cortex. EE can be considered and useful strategy to block BS effects, a phenomenon related to craving and relapse.

A pesquisa de substâncias biologicamente ativas, advinda principalmente de plantas, tem levado a descoberta de moléculas clinicamente benéficas. A família Amaryllidaceae é conhecida por sintetizar alcalóides biologicamente ativos, principalmente do grupo tetraisoquinolínico. Estudos têm demonstrado que a atividade biológica destes vegetais está relacionada com a presença deste grupo de metabólitos secundários. No Rio Grande do Sul, é encontrado o gênero Hippeastrum, pertencente a família Amaryllidaceae. Neste trabalho, realizou-se a investigação preliminar de alcalóides dos extratos de Hippeastrum papilio, coletada na região serrana do estado. Foram isoladas 12 substâncias, nas quais 9 apresentam carcaterísticas químicas de alcalóides de Amaryllidaceae. Estudos preliminares de CLAE-EM e CG-EM apontam para a existência de alcalóides de núcleos licorina e haemantamina, além de núcleo galantamina, em menor quantidade. Estas análises também mostram a possibilidade de estruturas inéditas. Os extratos enriquecidos em alcalóides de Hippeastrum papilio demonstraram uma grande capacidade de inibição da enzima acetilcolinesterase, pelo método da bioutografia em cromatoplaca. Além disso, foi realizada a análise comportamental do alcalóide montanina, previamente isolada de Hippeastrum vittatum Este alcalóide foi avaliado na tarefa de reconhecimento de objeto, com administração intrahipocampal, testado 24 horas pós-treino (memória de longa duração). Obteve-se curva dose-resposta para o alcalóide, com dose pró-cognitiva estatisticamente significante de 1μg/μl. Esta mesma dose foi avaliada na mesma tarefa para obtenção de curva temporal. Montanina demonstrou atividade pró-cognitiva na mesma tarefa e testada 24 horas pós-treino, em administração imediatamente pós-treino, 180 minutos pós-treino, mas não em 360 min pós-treino. O alcalóide montanina também foi avaliado quanto ao perfil de inibição da enzima acetilcolinesterase, utilizando método de ultravioleta. Obteve-se inibição da enzima em concentrações de 10 μM, 100 μM e 1 mM. Os resultados obtidos neste trabalho apontam para a necessidade de continuação da investigação química de Hippeastrum papilio, motivada pelo grande potencial de inibição da enzima acetilcolinesterase e por possibilidade de isolamento de estruturas inéditas. Além disso, foi confirmado um grande potencial pró-cognitivo do alcalóide montanina, demonstrado comportamentalmente, além de inibir a enzima acetilcolinesterase, atividade esta necessária e importante para que uma substância seja candidata à terapia da Doença de Alzheimer. / A search for biologically active substances in plants has led to the discovery of clinically beneficial molecules. The family Amaryllidaceae is known to synthesize biologically active alkaloids, principally of the tetraisoquinolinic group. Studies have shown that the biological activity of these plants is due to the presence of these secondary metabolites. The Hippeastrum genus, belonging to the Amaryllidaceae family, is found in Rio Grande do Sul. A preliminary investigation of alkaloids from extracts of Hippeastrum papilio, collected in the mountain region of the Rio Grande do Sul was done in this work. Twelve substances were isolated, in which nine have chemical profile of Amaryllidaceae alkaloids. Preliminary studies with HPLC-MS and GC-MS showed the existence of lycorine and haemantamine type alkaloids, as well as galantamine type alkaloids in a lower quantity. These analysis also showed a possibile presence of unknown structures. The extracts, enriched in alkaloids of Hippeastrum papilio, demonstrated a great ability to inhibit the acetylcholinesterase enzyme by a rapid thin layer chromatography bioautographic method. Furthermore, it was done a behavior analysis of montanine, previously isolated from Hippeastrum vittatum This alkaloid was evaluated in recognition object task with intrahippocampal administration and tested for 24 hours postrainig (long term memory). There was found a doseeffect curve of montanine with cognitive-enhanced dose at 1μg/μl. This dose was evaluated in the same task for temporal-curve. Montanine showed procognitive activity in immediately postraining administration and 180 minutes postraining but not with 360 min postraining in the same task. The acetylcholinesterase inhibition profile of montanine alkaloid was also evaluated by a ultraviolet method. The enzyme was inhibited in concentrations of 10 μM, 100 μM and 1 mM of montanine. The results obtained in the present study show a need for further chemical investigation on Hippeastrum papilio due to its large potential for inhibition of the acetylcholinesterase and isolation of potentially new structures. Moreover, these results confirm the great pro-cognitive potential of montanine, behaviorally demonstrated, as well as its ability to inhibit the acetylcholinesterase enzime, which makes the alkaloid a candidate substance for the treatment of Alzheimer's Disease.