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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Defining Nostalgia and Its Functions: A Review

Andersson, Jimmy January 2011 (has links)
Nostalgia is a psychological phenomenon we all can relate to but have a hard time to define. What characterizes the mental state of feeling nostalgia? What psychological function does it serve? Different published materials in a wide range of fields, from consumption research and sport science to clinical psychology, psychoanalysis and sociology, all have slightly different definition of this mental experience. Some claim it is a psychiatric disease giving melancholic emotions to a memory you would consider a happy one, while others state it enforces positivity in our mood. First in this paper a thorough review of the history of nostalgia is presented, then a look at the body of contemporary nostalgia research to see what it could be constituted of. Finally, we want to dig even deeper to see what is suggested by the literature in terms of triggers and functions. Some say that digitally recorded material like music and videos has a potential nostalgic component, which could trigger a reflection of the past in ways that was difficult before such inventions. Hinting towards that nostalgia as a cultural phenomenon is on a rising scene. Some authors say that odors have the strongest impact on nostalgic reverie due to activating it without too much cognitive appraisal. Cognitive neuropsychology has shed new light on a lot of human psychological phenomena‘s and even though empirical testing have been scarce in this field, it should get a fair scrutiny within this perspective as well and hopefully helping to clarify the definition of the word to ease future investigations, both scientifically speaking and in laymen‘s retro hysteria.Keywords:
2

The role of the autobiographical experiences with emotional significance of an architect in design conjecturing

Solovyova, Irina 15 May 2009 (has links)
The dissertation investigates the role of autobiographical memories with emotional significance in architectural design conjecturing. The dissertation is structured as a set of individual articles (chapters), each can be read independently. To set the background to the empirical research, an overview of models of the design process, intuition in design, memory, emotion and place are presented. The empirical research consists of comparison of two case studies. Ethnographic methods were used for data collection. Direct analysis, indirect analysis (content analysis of protocols) and analysis of language for affect were used to scrutinize the data. Findings clearly indicate the utilization of autobiographical memories with emotional significance in design conjecturing. The study describes the types of autobiographical memories with emotional significance and purpose of their use in design conjecturing. In general, the dissertation study indicated that half of thought content used by architects during design conjecturing comes from their autobiographical experience. At the same time, personal experiences of students are neglected in architectural education. Overview of the current status of architectural education leads to the argument that academia is due for a paradigm change. The dissertation provides suggestion on the direction of changes in design education.
3

Valence-specific Enhancements in Visual Processing Regions Support Negative Memories:

Kark, Sarah Marie January 2019 (has links)
Thesis advisor: Elizabeth A. Kensinger / Research in four parts examines the effects of valence on the neural processes that support emotional memory formation and retrieval. Results show a consistent valence-specific enhancement of visuocortical engagement along the ventral visual stream and occipital cortex that supports negative memories to a greater extent than positive memories. Part I investigated the effects of valence on the interactions between trial-level physiological responses to emotional stimuli (i.e., heart rate deceleration) during encoding and subsequent memory vividness. Results showed that negative memory vividness, but not positive or neutral memory vividness, is tied to arousal-related enhancements of amygdala coupling with early visual cortex during encoding. These results suggest that co-occurring parasympathetic arousal responses and amygdala connectivity with early visual cortex during encoding influence subsequent memory vividness for negative stimuli, perhaps reflecting enhanced memory-relevant perceptual enhancements during encoding of negative stimuli. Part II examined links between individual differences in post-encoding increases is amygdala functional connectivity at rest and the degree and direction of emotional memory biases at retrieval. Results demonstrated that post-encoding increases in amygdala resting state functional connectivity with visuocortical and frontal regions predicted the degree of negative memory bias (i.e., better memory for unpleasant compared to pleasant stimuli) and positive memory bias, respectively. Further, the effect of amygdala-visuocortical post-encoding coupling on behavioral negative memory bias was completely mediated by greater retrieval-related activity for negative stimuli in visuocortical areas. These findings suggest that those individuals with a negative memory bias tend to engage visual processing regions across multiple phases of memory more than individuals with a positive memory bias. While Parts I-II examined encoding-related memory processes, Part III examined the effects of valence on true and false subjective memory vividness at the time of retrieval. The findings showed valence-specific enhancements in regions of the ventral visual stream (e.g., inferior temporal gyrus and parahippocampal cortex) support negative memory vividness to a greater extent than positive memory vividness. However, activation of the parahippocampal cortex also drove a false sense of negative memory vividness. Together, these findings suggest spatial overlap in regions that support negative true and false memory vividness. Lastly, Part IV utilized inhibitory repetitive transcranial magnetic stimulation (rTMS) to test if a portion of occipito-temporal cortex that showed consistent valence-specific effects of negative memory in Parts I-III was necessary for negative memory retrieval. Although some participants showed the hypothesized effect, there was no group-level evidence of a neuromodulatory effect of occipito-temporal cortex rTMS on negative memory retrieval. Together, the results of the current dissertation work highlight the importance of valence-based models of emotional memory and consistently implicated enhanced visuosensory engagement across multiple phases of memory. By identifying valence-specific effects of trial-level physiological arousal during encoding, post-encoding amygdala coupling during early consolidation, and similarities and differences between true and false negative memories, the present set of work has important implications for how negative and positive memories are created and remembered differently. / Thesis (PhD) — Boston College, 2019. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Psychology.
4

Clorfeniramina microinjetada no hipocampo dorsal reverte e efeito ansiolítico da L-histidina e prejudica a memória emocional de camundongos / Dorsal hippocampal microinjections of chlorpheniramine reverses anxiolitic-like effect of L-histidine and impairs mice emotional memory.

Souza, Lucas Canto de 30 September 2011 (has links)
O nosso grupo tem investigado os efeitos da Clorfeniramina (CPA), antagonista H1, e da L-histidina (LH), uma droga precursora da síntese de histamina, sobre a ansiedade e a memória emocional. Diante disso, os objetivos desse estudo foram investigar os efeitos LH administrada i.p. e da CPA microinjetada no hipocampo dorsal sobre a ansiedade e a memória emocional de camundongos submetidos ao labirinto em cruz elevado (LCE). O experimento foi realizado em dois dias consecutivos. No primeiro dia (T1) 71 camundongos machos da cepa Suíço-Albino pesando 25-35g foram pré-tratados i.p. com salina (SAL) ou LH (500mg/Kg). Após duas horas, os sujeitos receberam microinjeção de SAL ou CPA (0,016nmol; 0,052nmol; 0,16nmol/0,1l) no hipocampo dorsal. Após cinco minutos, os animais foram expostos ao LCE por cinco minutos. Vinte quatro horas depois, o mesmo protocolo experimental foi adotado na reexposição (T2). Os animais foram distribuídos aleatoriamente em 8 grupos de acordo com o tratamento farmacológico: SAL/SAL (n=9), SAL/CPA1 (n=9), SAL/CPA2 (n=10), SAL/CPA3 (n=8), LH/SAL (n=10), LH/CPA1 (n=8), LH/CPA2 (n=8) e LH/CPA3 (n=9). As três doses de CPA microinjetadas no hipocampo dorsal não alteraram a porcentagem de tempo gasto nos braços abertos (%TBA) na exposição ao LCE: T1 SAL/CPA1 (46,13±4,45); SAL/CPA2 (47,59±4,89); SAL/CPA3 (44,30±6,65) quando comparados com o grupo controle SAL/SAL (35,84±2,77) e não alteraram o número de entradas nos braços fechados (EBF) SAL/CPA1 (8,56±1,06); SAL/CPA2 (9,70±1,10); SAL/CPA3 (9,38±1,25) - quando comparados com o grupo controle SAL/SAL (10,56±1,11). A administração i.p. de LH aumentou a %TBA em T1 para o grupo LH/SAL (59,79±4,71), quando comparado ao grupo controle SAL/SAL (35,84±2,77), mas não alterou o EBF: LH/SAL (9,20±1,78) e SAL/SAL (10,56±1,11). Os animais do grupo LH/CPA3 diminuíram %TBA (32,25±4,81) em T1 quando comparados com o grupo LH/SAL (59,79±4,71). Os animais do grupo SAL/CPA1 não apresentaram diminuição da %TBA em T2 (T1: 46,13±4,45; T2: 39,38±6,53). O mesmo foi observado para os sujeitos dos grupos LH/CPA2 (T1: 50,10±3,99; T2: 40,97±8,22) e LH/CPA3 (T1: 32,25±4,81; T2: 32,16±6,93). Nós concluímos que: a CPA microinjetada no hipocampo dorsal de camundongos não apresenta efeito sobre a ansiedade; a administração intraperitoneal de LH apresenta efeito ansiolítico em camundongos expostos ao LCE e que esse efeito é revertido pela maior dose de CPA (0,16nmol/0,1l); são necessárias maiores doses de CPA para que haja prejuízo na memória emocional de camundongos reexpostos ao LCE quando os níveis de histamina no hipocampo dorsal estão elevados. / Our group has been investigating the effects of Chlorpheniramine (CPA), a histaminergic H1 antagonist, and of L-Histidine (LH), a histamine precursor, on anxiety-related behaviors and emotional memory. Thus the aim of this study was to investigate the effects of LH i.p. injections and of dorsal intra-hippocampal microinjections of Chlorpheniramine (CPA) on anxiety-related behaviors and emotional memory in male mice using elevated plus-maze (EPM). The experiment was performed in two days. On the first day (T1) 71 male Swiss Albino mice of body weight 25- 35g were pre-treated with saline (SAL) i.p. or LH (500mg/Kg) i.p. After two hours they were treated with dorsal intra-hippocampal microinjections of SAL or CPA (0.016nmol; 0.052nmol; 0.16nmol/0,1l). Five minutes after intra-hippocampal microinjections the animals were exposed to EPM for 5 minutes. Twenty four hours later the same protocol was repeated (T2). The animals were randomly assigned to 8 groups based on drug treatment: SAL/SAL (n=9), SAL/CPA1 (n=9), SAL/CPA2 (n=10), SAL/CPA3 (n=8), LH/SAL (n=10), LH/CPA1 (n=8), LH/CPA2 (n=8) and LH/CPA3 (n=9). All three doses of intra-hippocampal microinjections of CPA did not change the percentage of time spent in the open-arms (%OAT) on T1 SAL/CPA1 (46.13±4.45); SAL/CPA2 (47.59±4.89); SAL/CPA3 (44.30±6.65) when compared to control group SAL/SAL (35.84±2.77) and did not change the enclosed arm entries (EAE) SAL/CPA1 (8.56±1.06); SAL/CPA2 (9.70±1.10); SAL/CPA3 (9.38±1.25) when compared to control group SAL/SAL (10.56±1.11). Intraperitoneal injections of LH increased %OAT on T1 on LH/SAL group (59.79±4.71), when compared to control group SAL/SAL (35.84±2.77), but not EAE LH/SAL (9.20±1.78) and SAL/SAL (10.56±1.11). Animals treated with LH and CPA3 (LH/CPA3) decreased %OAT (32.25±4.81) on T1 when compared to LH/SAL (59.79±4.71) group. SAL/CPA1 animals did not decreased %OAT on T2 (T1: 46.13±4.45; T2: 39.38±6.53). The same happened to LH/CPA2 (T1: 50.10±3.99; T2: 40.97±8.22) and LH/CPA3 (T1: 32.25±4.81; T2: 32.16±6.93) groups. Thus, we conclude that: dorsal intra-hippocampal microinjection of Chlorpheniramine has no effect on anxiety-related behaviors in male mice; intraperitoneal injection of L-Histidine has an anxiolytic-like effect in male mice exposed to elevated plus-maze, that is reversed by the higher dose of Chlorpheniramine (0.16nmol/0,1l); higher doses of CPA are necessary to impair emotional memory when the levels of hippocampal histamine are elevated.
5

Clorfeniramina microinjetada no hipocampo dorsal reverte e efeito ansiolítico da L-histidina e prejudica a memória emocional de camundongos / Dorsal hippocampal microinjections of chlorpheniramine reverses anxiolitic-like effect of L-histidine and impairs mice emotional memory.

Lucas Canto de Souza 30 September 2011 (has links)
O nosso grupo tem investigado os efeitos da Clorfeniramina (CPA), antagonista H1, e da L-histidina (LH), uma droga precursora da síntese de histamina, sobre a ansiedade e a memória emocional. Diante disso, os objetivos desse estudo foram investigar os efeitos LH administrada i.p. e da CPA microinjetada no hipocampo dorsal sobre a ansiedade e a memória emocional de camundongos submetidos ao labirinto em cruz elevado (LCE). O experimento foi realizado em dois dias consecutivos. No primeiro dia (T1) 71 camundongos machos da cepa Suíço-Albino pesando 25-35g foram pré-tratados i.p. com salina (SAL) ou LH (500mg/Kg). Após duas horas, os sujeitos receberam microinjeção de SAL ou CPA (0,016nmol; 0,052nmol; 0,16nmol/0,1l) no hipocampo dorsal. Após cinco minutos, os animais foram expostos ao LCE por cinco minutos. Vinte quatro horas depois, o mesmo protocolo experimental foi adotado na reexposição (T2). Os animais foram distribuídos aleatoriamente em 8 grupos de acordo com o tratamento farmacológico: SAL/SAL (n=9), SAL/CPA1 (n=9), SAL/CPA2 (n=10), SAL/CPA3 (n=8), LH/SAL (n=10), LH/CPA1 (n=8), LH/CPA2 (n=8) e LH/CPA3 (n=9). As três doses de CPA microinjetadas no hipocampo dorsal não alteraram a porcentagem de tempo gasto nos braços abertos (%TBA) na exposição ao LCE: T1 SAL/CPA1 (46,13±4,45); SAL/CPA2 (47,59±4,89); SAL/CPA3 (44,30±6,65) quando comparados com o grupo controle SAL/SAL (35,84±2,77) e não alteraram o número de entradas nos braços fechados (EBF) SAL/CPA1 (8,56±1,06); SAL/CPA2 (9,70±1,10); SAL/CPA3 (9,38±1,25) - quando comparados com o grupo controle SAL/SAL (10,56±1,11). A administração i.p. de LH aumentou a %TBA em T1 para o grupo LH/SAL (59,79±4,71), quando comparado ao grupo controle SAL/SAL (35,84±2,77), mas não alterou o EBF: LH/SAL (9,20±1,78) e SAL/SAL (10,56±1,11). Os animais do grupo LH/CPA3 diminuíram %TBA (32,25±4,81) em T1 quando comparados com o grupo LH/SAL (59,79±4,71). Os animais do grupo SAL/CPA1 não apresentaram diminuição da %TBA em T2 (T1: 46,13±4,45; T2: 39,38±6,53). O mesmo foi observado para os sujeitos dos grupos LH/CPA2 (T1: 50,10±3,99; T2: 40,97±8,22) e LH/CPA3 (T1: 32,25±4,81; T2: 32,16±6,93). Nós concluímos que: a CPA microinjetada no hipocampo dorsal de camundongos não apresenta efeito sobre a ansiedade; a administração intraperitoneal de LH apresenta efeito ansiolítico em camundongos expostos ao LCE e que esse efeito é revertido pela maior dose de CPA (0,16nmol/0,1l); são necessárias maiores doses de CPA para que haja prejuízo na memória emocional de camundongos reexpostos ao LCE quando os níveis de histamina no hipocampo dorsal estão elevados. / Our group has been investigating the effects of Chlorpheniramine (CPA), a histaminergic H1 antagonist, and of L-Histidine (LH), a histamine precursor, on anxiety-related behaviors and emotional memory. Thus the aim of this study was to investigate the effects of LH i.p. injections and of dorsal intra-hippocampal microinjections of Chlorpheniramine (CPA) on anxiety-related behaviors and emotional memory in male mice using elevated plus-maze (EPM). The experiment was performed in two days. On the first day (T1) 71 male Swiss Albino mice of body weight 25- 35g were pre-treated with saline (SAL) i.p. or LH (500mg/Kg) i.p. After two hours they were treated with dorsal intra-hippocampal microinjections of SAL or CPA (0.016nmol; 0.052nmol; 0.16nmol/0,1l). Five minutes after intra-hippocampal microinjections the animals were exposed to EPM for 5 minutes. Twenty four hours later the same protocol was repeated (T2). The animals were randomly assigned to 8 groups based on drug treatment: SAL/SAL (n=9), SAL/CPA1 (n=9), SAL/CPA2 (n=10), SAL/CPA3 (n=8), LH/SAL (n=10), LH/CPA1 (n=8), LH/CPA2 (n=8) and LH/CPA3 (n=9). All three doses of intra-hippocampal microinjections of CPA did not change the percentage of time spent in the open-arms (%OAT) on T1 SAL/CPA1 (46.13±4.45); SAL/CPA2 (47.59±4.89); SAL/CPA3 (44.30±6.65) when compared to control group SAL/SAL (35.84±2.77) and did not change the enclosed arm entries (EAE) SAL/CPA1 (8.56±1.06); SAL/CPA2 (9.70±1.10); SAL/CPA3 (9.38±1.25) when compared to control group SAL/SAL (10.56±1.11). Intraperitoneal injections of LH increased %OAT on T1 on LH/SAL group (59.79±4.71), when compared to control group SAL/SAL (35.84±2.77), but not EAE LH/SAL (9.20±1.78) and SAL/SAL (10.56±1.11). Animals treated with LH and CPA3 (LH/CPA3) decreased %OAT (32.25±4.81) on T1 when compared to LH/SAL (59.79±4.71) group. SAL/CPA1 animals did not decreased %OAT on T2 (T1: 46.13±4.45; T2: 39.38±6.53). The same happened to LH/CPA2 (T1: 50.10±3.99; T2: 40.97±8.22) and LH/CPA3 (T1: 32.25±4.81; T2: 32.16±6.93) groups. Thus, we conclude that: dorsal intra-hippocampal microinjection of Chlorpheniramine has no effect on anxiety-related behaviors in male mice; intraperitoneal injection of L-Histidine has an anxiolytic-like effect in male mice exposed to elevated plus-maze, that is reversed by the higher dose of Chlorpheniramine (0.16nmol/0,1l); higher doses of CPA are necessary to impair emotional memory when the levels of hippocampal histamine are elevated.
6

The hypothalamic-pituitary-adrenal axis in depression : a focus on the hippocampus

Symonds, Catherine January 2014 (has links)
Background: The hypothalamic-pituitary-adrenal (HPA) axis has been implicated in the aetiopathology of depression, and the incidence of HPA dysfunction tends to increase with the severity of treatment resistance. In healthy volunteers (HV), both acute and chronic hypercortisolaemia causes cognitive impairment, including emotional memory. The exact mechanism of this remains unclear; however the action of cortisol on corticosteroid receptors in the hippocampus appears to be crucial and this may also be important in the aetiopathology of depression. The aim of this thesis was to investigate acute and chronic states of the HPA axis, and its role on neurocognition in HV and treatment resistant depression (TRD). Methods: The acute action of cortisol in HV was examined through meta-analysis of the literature. In HV, the acute, non-genomic effects of hydrocortisone on the hippocampus were measured using pharmacological challenge functional magnetic resonance imaging (phMRI) and the effects on the working memory n-back task during functional magnetic resonance imaging (fMRI). Additionally, the neurocognitive effects in TRD patients, who are theorised to have chronically elevated corticosteroids, were compared to age and sex matched HV using the n-back task and a novel emotional encoding-retrieval task. Finally the acute effects of hydrocortisone on the whole brain were measured in TRD compared to HV using phMRI.Results: Meta-analysis results demonstrated an adverse effect on performance in retrieval tasks, but not encoding, after an acute rise in cortisol in HV, with a trend towards sparing of emotional memories. Using phMRI, hydrocortisone caused a time dependent increase in signal in the hippocampus, as well as an increased signal in the ventrolateral prefrontal cortex and a decreased signal in the hippocampus during the n-back task. Patients with TRD, when compared with HV, had a decreased signal in the dorsolateral prefrontal cortex during the n-back task. Additionally, during the emotional encoding-retrieval task, regardless of the emotional content, the patients showed a decrease in signal in the posterior cingulate during encoding and an increase in the posterior insula during retrieval. During retrieval of positive versus neutral images, there was an increase in signal in the anterior cingulate. The earlier phMRI findings were not reproduced in either the TRD or age and sex matched controls. Conclusions: This work developed and examined a new technique to explore the relationship between the HPA axis and depression, as well as exploring the neurocognitive difference between TRD and HV. A non-genomic, acute effect of cortisol on the hippocampus was demonstrated in HV, as well as differences in processing emotional memories both acutely in HV and also in TRD patients. Further work needs to be done to develop the phMRI technique further and explore the aetiopathological role of the HPA axis in depression, focussing on the hippocampus.
7

The Expression of Dopamine-Related Genes and Behavioral Performance in Mice

Dershem, Victoria Lynne January 2016 (has links)
No description available.
8

Histamina intra-amídala modula a memória aversiva de camundongos submetidos à esquiva inibitória, mas não à reexposição no LCE / Histamine Intra-amygdala Modulation on Aversive Memory for Mice-subjected Inhibitory Avoidance Task while not in the Elevated Plus-maze.

Pitta, Fernanda Daher 22 August 2013 (has links)
O Sistema Neural Histaminérgico tem importante papel na memória emocional, ansiedade e medo, processos com mediação pela amídala. O presente estudo investigou os efeitos da histamina (HA) microinjetada na amídala préexposição/teste de aquisição e/ou pré-reexposição/teste de retenção sobre os comportamentos de camundongos submetidos ao Labirinto em Cruz Elevado (LCE) ou à caixa de Esquiva Inibitória (EI). Para tanto, os animais passaram por cirurgia para implantação bilateral de cânulas-guia 1 mm acima da amídala. Após recuperação, eles receberam infusões centrais bilaterais pré-testes (LCE) ou pré-sessões (EI) de salina (SAL) ou HA nas doses de 0,1; 0,5 e 1,0 g em volume de 0,1 l. Os testes no LCE consistiram na exposição dos camundongos ao aparato (T1) e, após 24 h, na sua reexposição (T2). O número de entradas e tempo total nos braços abertos e suas porcentagens (EBA, TBA, %EBA, %TBA, respectivamente) em T1 foram considerados medidas para inferir ansiedade e em T2 para inferência da memória. As sessões na caixa de EI se iniciaram com a habituação. Após 30 min, os camundongos passaram pelo treino 1, com choque nas patas quando da presença do animal no ambiente escuro. Depois de 2 min, houve o treino 2 e, após 24 h, o teste de retenção com ausência de choque. As latências de transição em direção ao ambiente escuro foram registradas. Ao final, para cada modelo experimental e dose, quatro grupos foram formados: SAL-SAL, SALHA, HA-SAL e HA-HA. A análise estatística incluiu a ANOVA de duas vias e teste post hoc de Duncan. Para distribuições não homogêneas foram utilizados os testes de Kruskal-Wallis e Wilcoxon. O nível de significância adotado foi p0,05. No LCE, houve uma diminuição da %EBA e %TBA durante T2 em relação a T1 para todos os grupos tratados. Na comparação entre grupos em T1, a exploração dos braços abertos não mostrou alterações significativas, indicando que não houve alteração sobre o estado de ansiedade. Na caixa de EI, não houve aumento na latência de transição durante o teste de retenção para os grupos SAL-HA das doses de 0,5 e 1,0 g, em relação aos treinos 1 e 2; porém, no grupo HA-HA essa latência apresentou-se elevada. Para o LCE, houve ausência de efeito da HA intra-amídala sobre a memória emocional. Para a tarefa de EI, a HA nas doses de 0,5 e 1,0 g induziu prejuízo da evocação da memória emocional mediada pela amídala e evocação estado-dependente para os animais tratados com HA nos dois dias de sessões. / There is evidence that histamine (HA) modulates learning and memory in different types of behavioral tasks, but the exact course of modulation and its mechanisms are controversial. Well known that the amygdala plays an importante role in modulation of emotions. That is able to influence mnemonic processes. The goal of this research was to compare HA microinjected into the amygdala of mice subjected to elevated plus-maze (EPM) or inhibitory avoidance task (IAT) in effects on anxiety-related behavior and emotional memory. For this purpose, male Swiss mice, weighing from 25 and 35g, were bilaterally implanted with guide cannulas. The recovery took from three to five days after surgery, then behavioral tests in the EPM or IAT were performed on two consecutive days. In the first experiment, the animals received microinjections before Trial 1 of salina (SAL) or HA in the amygdala (0.1; 0.5 and 1.0 g by 0.1 l/side volume) and were exposed to EPM for 5 min. 24h later the same protocol was repeated (Trial 2). The second experiment consisted of four sessions in the IAT: Habituation, Training 1 and 2 (interval of 2min between the two; footshock; 0.5mA/3sec) and Test (24h later; without footshock). Mice were microinjected before Training 1 and Test with SAL or HA at the same dose mentioned. The animals were assigned into four groups for each experiment: SAL-SAL, SAL-HA, HA-SAL and HA-HA. The data was analyzed using two-way ANOVA and Duncans tests to the homogeneous data, and Kruskal-Wallis and Wilcoxon to the inhomogeneous distributions. For the tests in the EPM, the percentage of open arm entries (%OAE) were reduced in Trial 2 relative to Trial 1 for SAL-HA and HA-SAL and the percentage of time spent in the open arms (%OAT) also decreased in all groups at the doses of 0.5 and 1.0 g. No significant changes were observed in that measures in Trial 1 compared all groups, an EPM index of anxiety. For the sessions in the IAT, the step-through latency increased in SAL-SAL, HA-SAL and HA-HA on the test day relative to training day, and no statistical differences were observed to SAL-HA group. The latency were increased whith HA infusions pre-trial and pré-test as a condition. Based on our results, the HA intra-amygdala of mice at the doses studied is not involved on the anxiety-like behaviors and mnemonic process in the EPM, but impairs the emotional memory retrieval in the IAT at the doses of 0.5 and 1.0 g. HA intra-amygdala also induces state-dependent emotional memory in those doses for HA-HA group. We suggest that HA is distinctly involved at pathways that mediates anxiety and fear.
9

Histamina intra-amídala modula a memória aversiva de camundongos submetidos à esquiva inibitória, mas não à reexposição no LCE / Histamine Intra-amygdala Modulation on Aversive Memory for Mice-subjected Inhibitory Avoidance Task while not in the Elevated Plus-maze.

Fernanda Daher Pitta 22 August 2013 (has links)
O Sistema Neural Histaminérgico tem importante papel na memória emocional, ansiedade e medo, processos com mediação pela amídala. O presente estudo investigou os efeitos da histamina (HA) microinjetada na amídala préexposição/teste de aquisição e/ou pré-reexposição/teste de retenção sobre os comportamentos de camundongos submetidos ao Labirinto em Cruz Elevado (LCE) ou à caixa de Esquiva Inibitória (EI). Para tanto, os animais passaram por cirurgia para implantação bilateral de cânulas-guia 1 mm acima da amídala. Após recuperação, eles receberam infusões centrais bilaterais pré-testes (LCE) ou pré-sessões (EI) de salina (SAL) ou HA nas doses de 0,1; 0,5 e 1,0 g em volume de 0,1 l. Os testes no LCE consistiram na exposição dos camundongos ao aparato (T1) e, após 24 h, na sua reexposição (T2). O número de entradas e tempo total nos braços abertos e suas porcentagens (EBA, TBA, %EBA, %TBA, respectivamente) em T1 foram considerados medidas para inferir ansiedade e em T2 para inferência da memória. As sessões na caixa de EI se iniciaram com a habituação. Após 30 min, os camundongos passaram pelo treino 1, com choque nas patas quando da presença do animal no ambiente escuro. Depois de 2 min, houve o treino 2 e, após 24 h, o teste de retenção com ausência de choque. As latências de transição em direção ao ambiente escuro foram registradas. Ao final, para cada modelo experimental e dose, quatro grupos foram formados: SAL-SAL, SALHA, HA-SAL e HA-HA. A análise estatística incluiu a ANOVA de duas vias e teste post hoc de Duncan. Para distribuições não homogêneas foram utilizados os testes de Kruskal-Wallis e Wilcoxon. O nível de significância adotado foi p0,05. No LCE, houve uma diminuição da %EBA e %TBA durante T2 em relação a T1 para todos os grupos tratados. Na comparação entre grupos em T1, a exploração dos braços abertos não mostrou alterações significativas, indicando que não houve alteração sobre o estado de ansiedade. Na caixa de EI, não houve aumento na latência de transição durante o teste de retenção para os grupos SAL-HA das doses de 0,5 e 1,0 g, em relação aos treinos 1 e 2; porém, no grupo HA-HA essa latência apresentou-se elevada. Para o LCE, houve ausência de efeito da HA intra-amídala sobre a memória emocional. Para a tarefa de EI, a HA nas doses de 0,5 e 1,0 g induziu prejuízo da evocação da memória emocional mediada pela amídala e evocação estado-dependente para os animais tratados com HA nos dois dias de sessões. / There is evidence that histamine (HA) modulates learning and memory in different types of behavioral tasks, but the exact course of modulation and its mechanisms are controversial. Well known that the amygdala plays an importante role in modulation of emotions. That is able to influence mnemonic processes. The goal of this research was to compare HA microinjected into the amygdala of mice subjected to elevated plus-maze (EPM) or inhibitory avoidance task (IAT) in effects on anxiety-related behavior and emotional memory. For this purpose, male Swiss mice, weighing from 25 and 35g, were bilaterally implanted with guide cannulas. The recovery took from three to five days after surgery, then behavioral tests in the EPM or IAT were performed on two consecutive days. In the first experiment, the animals received microinjections before Trial 1 of salina (SAL) or HA in the amygdala (0.1; 0.5 and 1.0 g by 0.1 l/side volume) and were exposed to EPM for 5 min. 24h later the same protocol was repeated (Trial 2). The second experiment consisted of four sessions in the IAT: Habituation, Training 1 and 2 (interval of 2min between the two; footshock; 0.5mA/3sec) and Test (24h later; without footshock). Mice were microinjected before Training 1 and Test with SAL or HA at the same dose mentioned. The animals were assigned into four groups for each experiment: SAL-SAL, SAL-HA, HA-SAL and HA-HA. The data was analyzed using two-way ANOVA and Duncans tests to the homogeneous data, and Kruskal-Wallis and Wilcoxon to the inhomogeneous distributions. For the tests in the EPM, the percentage of open arm entries (%OAE) were reduced in Trial 2 relative to Trial 1 for SAL-HA and HA-SAL and the percentage of time spent in the open arms (%OAT) also decreased in all groups at the doses of 0.5 and 1.0 g. No significant changes were observed in that measures in Trial 1 compared all groups, an EPM index of anxiety. For the sessions in the IAT, the step-through latency increased in SAL-SAL, HA-SAL and HA-HA on the test day relative to training day, and no statistical differences were observed to SAL-HA group. The latency were increased whith HA infusions pre-trial and pré-test as a condition. Based on our results, the HA intra-amygdala of mice at the doses studied is not involved on the anxiety-like behaviors and mnemonic process in the EPM, but impairs the emotional memory retrieval in the IAT at the doses of 0.5 and 1.0 g. HA intra-amygdala also induces state-dependent emotional memory in those doses for HA-HA group. We suggest that HA is distinctly involved at pathways that mediates anxiety and fear.
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Age differences in arousal, perception of affective pictures, and emotional memory enhancement : Appraisal, Electrodermal activity, and Imaging data

Gavazzeni, Joachim January 2008 (has links)
<p>In contrast to effortful cognitive functions, emotional functioning may remain stable or even be enhanced in older adults. It is unclear how affective functions in aging correspond to subjective experiences and physiological changes. In <b>Study I</b>, ratings of emotional intensity and neural activity to facial expressions using functional magnetic resonance imaging (fMRI) were analyzed in younger and older adults. Negative expressions resulted in increased neural activity in the right amygdala and hippocampus in younger adults, and increased activation in the right insular cortex in older adults. There were no age differences in subjective ratings. In <b>Study II</b>, subjective ratings of, and skin conductance response (SCR) to, neutral and negative pictures were studied. The ratings of negative pictures were higher for older adults compared to younger adults. SCRs increased in both age groups for the negative pictures, but magnitude of SCRs was significantly larger in younger adults. Finally, in <b>Study III</b>, emotional memory after a one-year retention interval was tested. The memory performance of both age groups was higher in response to negative pictures compared to neutral ones, although the performance was generally higher for younger adults. SCR at encoding was the better arousal predictor for memory, but only in younger adults. The results indicate age-related changes in affective processing. Age differences may involve a gradual shift from bottom-up processes, to more top-down processes. The results are discussed in a wider lifespan perspective taking into consideration the accumulated life experience of older adults.</p>

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