No description available.

No description available.

The ability of the indirect dopamine agonist, amphetamine, to produce behavioral sensitization was assessed in adult D₁A-deficient and wild-type mice. It was originally predicted that : 1) dopamine (DA) D₁-like receptors are necessary for the occurrence of short- and long-term amphetamine-induced behavioral sensitization, 2) DA D₁-like receptors are necessary for environmental conditioning factors associated with amphetamine-induced behavioral sensitiazation, and 3) DA D₅ receptors are required for amphetamine-induced behavioral sensitization. Locomotor activity and sterotyped sniffing were assessed in each of three experiments.

The present study examined operant extinction in a controlled setting using a human operant paradigm. Participants watched a preferred video. During the video, either the video or audio portion of the video was selectively removed, on average every 15 s. Participants could restore the video by pressing a force transducer. In one group, relatively low forces were required (250 g) and in the other relatively high forces were required (750 g). At the 20th and 30th minute during the session, the video or audio was removed but the participants could not restore the component for 30 s. The results showed that responding during the probe increased relative to 30-s periods prior and following the probe, characteristic of an extinction burst. The results also showed that overall we saw increases in force under high force conditions during extinction when presses no longer produced sound or video, and force changed little during the low force conditions. We conclude that extinction bursts are a robust phenomenon that can be demonstrated in humans. Additionally, the topographies, i.e. force, established during baseline and the modality of the consequence appear to be two variables determining the short-term course of extinction.

The possible application of habit reversal to mentally ill institutional residents has not been investigated. While habit reversal holds considerable promise as a treatment mode, due to its rapid success and patient involvement in controlling his-her own behavior, further research is in order. To investigate the generality of habit reversal to an institutionalized population, the present study utilized self-monitoring, which has been found to be effective with hospitalized patients, and habit reversal, which has been found to be effective with a non-hospitalized population, as a treatment package for eliminating nervous tics. There are four major purposes for doing this present study: a) to see if modified habit reversal techniques could be used to successfully treat tics in institutionalised mental ill individuals, and in doing so look at; b) the effectiveness of procedures that involve the subject controlling his/her own behavior with that kind of population; c) To evaluate the within-in subject generality of the procedures by using a generalization measure in each subject’s living environment; and d) since Azrin and Nunn’s (1973) use of habit reversal was restricted to baseline-treatment (AB) replications, to provide an experimental analysis using a multiple baseline design.

Forty-five male, Sprague Dawley rats were used to determine if external stimuli could influence the length of a conditioned taste aversion. Animals were given a novel taste (sucrose), and then injected with one of three different substances, marihuana, LiCI, or saline. The animals were then placed into either a stimulation condition, a non-stimulation condition, or returned to the home cage. The stimulation condition contained aversive stimuli in the form of bright, flashing lights and loud noises. The other conditions had no aversive stimulation. It was expected that the animals receiving injections of marihuana would have an increase in their responsiveness to events in their environment, and thus be more sensitive to the aversive stimulation. By reacting to not only the internal toxicosis, but also the aversive external stimulation, it was hoped that the animals would undergo a more totally aversive experience in the stimulation condition. This increase in discomfort with the addition of external aversive stimuli was expected to be reflected in the development of longer conditioned aversions in animals receiving the marihuana and stimulation. The LiCI group was expected to show no reactiveness to the external aversive stimuli. Although taste aversions did develop in the marihuana and LiCI groups, no differences were found between treatment conditions nor between toxins. This study shows that external aversive stimuli do not play a role in an animal's conditioned aversion to sucrose after injection of a toxic drug such as marihuana or LiCI.

No description available.

O sistema endocanabinoide é composto por ligantes endógenos, enzimas responsáveis pela síntese e degradação desses ligantes, além de receptores específicos. As duas principais moléculas endógenas, anandamida (AEA) e 2- araquidonilglicerol (2-AG), após sintetizadas, são difundidos para a fenda sináptica e agem retrogradamente em receptores canabinóides do tipo 1 e/ou 2 (CB1 e CB2, respectivamente). A ação da AEA termina após processo de internalização seguido por hidrólise através da enzima FAAH (fatty acid amid hydrolase; amidohidrolase de acidos graxos), presente no neurônio pós-sináptico. O 2-AG, por sua vez, é degradado pela MAGL (monoacilglicerol lipase), localizada pré-sinapticamente. O receptor CB1 modula negativamente a liberação de diversos neurotransmissores no sistema nervoso central. A participação dos endocanabinoides é amplamente descrita em diversas estruturas cerebrais envolvidas na expressão de respostas relacionadas aos comportamentos de ansiedade e medo, tendo seus efeitos mediados principalmente por CB1 e CB2. Entretanto, o papel dos endocanabinoides em algumas estruturas ainda não está completamente elucidado. Dentre essas, destaca-se o Núcleo Leito da Estria Terminal (NLET), uma estrutura límbica com importante papel na integração de informações associadas com controle autonômico, endócrino e comportamental durante situações aversivas. Há poucas evidências da presença e do envolvimento do sistema endocanabinoide no NLET sobre a modulação de respostas de ansiedade. Desta forma, o objetivo do presente estudo foi avaliar o envolvimento do sistema endocanabinoide presente no NLET na modulação de respostas aversivas inata e aprendida. Para isso ratos Wistar (240g - 270g) foram implantados com cânulas guia bilateralmente no NLET para administração de drogas. Foram utilizados: veículo (DMSO 10%), antagonista de receptores CB1, o AM251 nas doses de 0,1 a 0,3 nmol/100nL e um inibidor da enzima FAAH, URB597 nas doses de 0,01 e 0,1 nmol/100nL. Cinco dias após a cirurgia estereotáxica, os animais foram submetidos ao teste de resposta inata do Labirinto em cruz elevado por 5 minutos. Avaliou-se o número de entradas e o tempo gasto nos braços abertos e fechados. Dois a três dias após, os animais foram submetidos ao protocolo do medo condicionado ao contexto, realizado em 3 dias consecutivos. No dia do teste, respostas comportamentais (tempo de congelamento) e autonômicas (Pressão arterial média; Frequência cardíaca, e Temperatura cutânea da cauda) foram continuamente avaliadas durante 10 min. Nossos resultados demonstraram que o bloqueio ou ativação de receptores CB1 no NLET não alterou as respostas de medo inato. Entretanto, no medo aprendido, o antagonismo de receptores CB1 no NLET aumentou o componente comportamental e pressórico. Ainda, a inibição da FAAH no NLET, via CB1, diminuiu o componente comportamental e pressórico da resposta emocional condicionada. Desta maneira, podemos sugerir que o sistema endocanabinoide presente no NLET modula respostas de medo aprendido, sem intervir nas respostas de medo inato. / The cannabinoid system is composed by two main endogenous ligands, enzymes responsible for synthesis and degradation of these ligands, and specific receptors. The two main endogenous molecules, anandamide (AEA) and 2-arachidonoylglycerol (2- AG), after synthesized post-synaptically, are released into the synaptic cleft, where they activate cannabinoid receptors type 1 and 2 (CB1 and CB2, respectively). AEA action terminates after internalization followed by enzymatic hydrolysis via FAAH (fatty acid amid hydrolase) located in the postsynaptic neuron. Meanwhile, 2-AG is degraded presynaptically by MAGL (monoacylglycerol lipase). CB1 receptor negatively modulates the release of several neurotransmitters in central nervous system. The endocannabinoid system is widely present in several brain structures involved on fear expression and anxiety-related responses, mostly mediated via CB1 and CB2 receptors. Nevertheless, the role of the endocannabinoids system role in specific brain structures is not yet completely elucidated. One structure in particular, is the Bed Nucleus of Stria Terminales (BNST), which is a limbic structure responsible for integration of autonomic, neuroendocrine and behavioral information during aversive situations. There is little evidence about the presence and involvement of endocannabinoid system in the BNST on anxiety responses modulation. Therefore, the aim of the present study was to evaluate the role of the endocannabinoid system in the BNST on the modulation of innate and learned aversive responses. Male Wistar rats (240 - 270g) were submitted to stereotaxic surgery for bilateral guide cannula implantation directed to the BNST, for drug administration. Animals received local injections of vehicle, AM251 (CB1-antagonist; 0,1 - 0,3 nmol/100nL), URB597 (an inhibitor of FAAH; 0,01 - 0,1 nmol/100nL). Five days after the stereotaxic surgery, animals were submitted to the innate response test, the elevated plus maze, for 5 minutes. The percentage of entries and time spent in open and the number of enclosed arms entries were analyzed. After two to three days, animals were submitted to the contextual fear conditioning protocol, performed in three consecutive days. On test day, behavioral (freezing) and autonomic responses (mean arterial pressure, heart rate and tail cutaneous temperature) were recorded for 10 min. Our data suggest that after CB1 receptors blocking or activation in the BNST do not promote changes in innate fear responses. However, during fear learning, CB1 receptor antagonism in the BNST increased freezing behavior and mean arterial pressure. In addition, FAAH inhibition in the BNST, via CB1, reduced freezing behavior and mean arterial pressure in the emotional conditioned response. These results suggest that endogenous cannabinoid system in the BNST can modulate defensive responses in fear learning, but not innate fear responses.

O sistema endocanabinoide é composto por ligantes endógenos, enzimas responsáveis pela síntese e degradação desses ligantes, além de receptores específicos. As duas principais moléculas endógenas, anandamida (AEA) e 2- araquidonilglicerol (2-AG), após sintetizadas, são difundidos para a fenda sináptica e agem retrogradamente em receptores canabinóides do tipo 1 e/ou 2 (CB1 e CB2, respectivamente). A ação da AEA termina após processo de internalização seguido por hidrólise através da enzima FAAH (fatty acid amid hydrolase; amidohidrolase de acidos graxos), presente no neurônio pós-sináptico. O 2-AG, por sua vez, é degradado pela MAGL (monoacilglicerol lipase), localizada pré-sinapticamente. O receptor CB1 modula negativamente a liberação de diversos neurotransmissores no sistema nervoso central. A participação dos endocanabinoides é amplamente descrita em diversas estruturas cerebrais envolvidas na expressão de respostas relacionadas aos comportamentos de ansiedade e medo, tendo seus efeitos mediados principalmente por CB1 e CB2. Entretanto, o papel dos endocanabinoides em algumas estruturas ainda não está completamente elucidado. Dentre essas, destaca-se o Núcleo Leito da Estria Terminal (NLET), uma estrutura límbica com importante papel na integração de informações associadas com controle autonômico, endócrino e comportamental durante situações aversivas. Há poucas evidências da presença e do envolvimento do sistema endocanabinoide no NLET sobre a modulação de respostas de ansiedade. Desta forma, o objetivo do presente estudo foi avaliar o envolvimento do sistema endocanabinoide presente no NLET na modulação de respostas aversivas inata e aprendida. Para isso ratos Wistar (240g - 270g) foram implantados com cânulas guia bilateralmente no NLET para administração de drogas. Foram utilizados: veículo (DMSO 10%), antagonista de receptores CB1, o AM251 nas doses de 0,1 a 0,3 nmol/100nL e um inibidor da enzima FAAH, URB597 nas doses de 0,01 e 0,1 nmol/100nL. Cinco dias após a cirurgia estereotáxica, os animais foram submetidos ao teste de resposta inata do Labirinto em cruz elevado por 5 minutos. Avaliou-se o número de entradas e o tempo gasto nos braços abertos e fechados. Dois a três dias após, os animais foram submetidos ao protocolo do medo condicionado ao contexto, realizado em 3 dias consecutivos. No dia do teste, respostas comportamentais (tempo de congelamento) e autonômicas (Pressão arterial média; Frequência cardíaca, e Temperatura cutânea da cauda) foram continuamente avaliadas durante 10 min. Nossos resultados demonstraram que o bloqueio ou ativação de receptores CB1 no NLET não alterou as respostas de medo inato. Entretanto, no medo aprendido, o antagonismo de receptores CB1 no NLET aumentou o componente comportamental e pressórico. Ainda, a inibição da FAAH no NLET, via CB1, diminuiu o componente comportamental e pressórico da resposta emocional condicionada. Desta maneira, podemos sugerir que o sistema endocanabinoide presente no NLET modula respostas de medo aprendido, sem intervir nas respostas de medo inato. / The cannabinoid system is composed by two main endogenous ligands, enzymes responsible for synthesis and degradation of these ligands, and specific receptors. The two main endogenous molecules, anandamide (AEA) and 2-arachidonoylglycerol (2- AG), after synthesized post-synaptically, are released into the synaptic cleft, where they activate cannabinoid receptors type 1 and 2 (CB1 and CB2, respectively). AEA action terminates after internalization followed by enzymatic hydrolysis via FAAH (fatty acid amid hydrolase) located in the postsynaptic neuron. Meanwhile, 2-AG is degraded presynaptically by MAGL (monoacylglycerol lipase). CB1 receptor negatively modulates the release of several neurotransmitters in central nervous system. The endocannabinoid system is widely present in several brain structures involved on fear expression and anxiety-related responses, mostly mediated via CB1 and CB2 receptors. Nevertheless, the role of the endocannabinoids system role in specific brain structures is not yet completely elucidated. One structure in particular, is the Bed Nucleus of Stria Terminales (BNST), which is a limbic structure responsible for integration of autonomic, neuroendocrine and behavioral information during aversive situations. There is little evidence about the presence and involvement of endocannabinoid system in the BNST on anxiety responses modulation. Therefore, the aim of the present study was to evaluate the role of the endocannabinoid system in the BNST on the modulation of innate and learned aversive responses. Male Wistar rats (240 - 270g) were submitted to stereotaxic surgery for bilateral guide cannula implantation directed to the BNST, for drug administration. Animals received local injections of vehicle, AM251 (CB1-antagonist; 0,1 - 0,3 nmol/100nL), URB597 (an inhibitor of FAAH; 0,01 - 0,1 nmol/100nL). Five days after the stereotaxic surgery, animals were submitted to the innate response test, the elevated plus maze, for 5 minutes. The percentage of entries and time spent in open and the number of enclosed arms entries were analyzed. After two to three days, animals were submitted to the contextual fear conditioning protocol, performed in three consecutive days. On test day, behavioral (freezing) and autonomic responses (mean arterial pressure, heart rate and tail cutaneous temperature) were recorded for 10 min. Our data suggest that after CB1 receptors blocking or activation in the BNST do not promote changes in innate fear responses. However, during fear learning, CB1 receptor antagonism in the BNST increased freezing behavior and mean arterial pressure. In addition, FAAH inhibition in the BNST, via CB1, reduced freezing behavior and mean arterial pressure in the emotional conditioned response. These results suggest that endogenous cannabinoid system in the BNST can modulate defensive responses in fear learning, but not innate fear responses.

I outline a framework for researching the effects of practice schedule on skill acquisition, based upon stage theories of information processing and stage theories of skill acquisition. Skilled performance requires stimulus identification, response selection, and response execution. I hypothesize that practice schedule affects learning in two types of information processing stages: stimulus-oriented and response-oriented stages. The loci of these effects differ based on the stage. In stimulus-oriented stages, practice schedule affects concept and categorization learning via contiguity of exemplars and feature saliency. In response-oriented stages, practice schedule affects the efficiency with which individuals produce a response by affecting response preparation. I evaluated this framework and theory with 4 experiments that manipulated practice schedule and amount of practice, in 2 domains with different information processing demands. Experiments~1~and~2 focused on response-oriented stages via a task that required participants to execute a multisegment movement according to a target time. Experiments~3~and~4 focused on stimulus-oriented stages via a task that required participants to categorize football play diagrams. Within the 2 task domains the amount of acquisition practice was manipulated to test whether different durations of acquisition training changed how practice schedules affected retention and transfer performance. The practice schedule manipulation had reliable effects on performance and learning when task performance involved either response preparation or induction of categorization rules. Practice schedule did not affect performance or learning when task performance involved categorization decisions, after the rules had been learned. Additionally, I report a novel method for quantifying amount of practice that allows comparisons across task domains.