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探討藥物引發制約反應之神經行為機制

本研究藉由測量制約場地偏好行為及制約活動量兩種制約反應,透過制約期及後測期對藥物配對刺激之操弄,探討制約刺激與酬賞性藥物配對之歷程及其相關之神經機制。本文所使用的為低劑量(1.5 mg/kg)之安非他命,採腹腔注射方式給藥。實驗一探討後測日呈現不同的藥物配對刺激組合對兩種制約反應之影響效果,實驗結果發現受試只對與藥物配對過的兩個以上元素刺激同時出現才能引發受試表現制約場地偏好,且受試對複合刺激的活動量皆顯著高於對單一元素刺激的活動量。實驗二在制約期分別將視覺刺激與觸覺刺激與藥物配對,後測期於藥物配對箱單獨呈現視覺刺激或兩者所組成的複合刺激,測量受試兩種制約反應。實驗結果發現視覺刺激與複合刺激皆能引發制約場地偏好,受試對複合刺激的活動量亦高於對視覺刺激的活動量。實驗三則是於制約前分別破壞受試之杏仁核、背側海馬或腹側海馬,並進行實驗二之制約實驗程序。結果發現破壞杏仁核顯著的減抑單一元素刺激所引發之制約場地偏好,但不影響複合刺激引發之制約場地偏好。破壞背側海馬及腹側海馬減抑複合刺激引發之制約場地偏好。但在制約活動量表現方面,這三個腦組織均未獲得較一致性的結果。總而言之,本研究得到制約刺激之連結強度確實可以透過制約場地偏好及制約活動量反映出差異,且結果支持Rescorla-Wagner元素理論對制約刺激與非制約刺激配對歷程之假設。由破壞杏仁核及海馬對受試表現制約場地偏好造成不等程度之影響,可見杏仁核與海馬所參與以藥物配對的制約之行為功能不同。

關鍵字:心理藥物學,安非他命,制約場地偏好,制約活動,元素理論,整體理論,大白鼠 / By measuring of conditioned place preference (CPP) and conditioned locomotion, the present study manipulated various patterns of environment by composing three different contextual stimuli in the test chamber during different stages of conditioning to investigate behavioral processing and neural mechanisms underlying the association of conditioned stimulus and psychoactive drug. A relatively low dose of amphetamine (1.5 mg/kg) administered via intraperitoneal route was conducted as drug treatment throughout the study. In Experiment 1, the effects of CPP and conditioned locomotion were evaluated as different patterns of contextual stimuli composed in the test chamber presented during post-conditioning stage. The results showed CPP was significantly induced in the environment with context stimuli composed by at least two elements. And, the magnitude of conditioned locomotion induced by compound stimulus was higher than that induced by a single elemental stimulus. In Experiment 2, the effects of CPP and conditioned locomotion induced by a two-element compound stimulus were evaluated in the subjects received the drug pairing with both of each element stimulus in separate during the conditioning stage. The CPP was reliable induced by that compound stimulus. Although such CPP effect could also induced by an elemental stimulus specifically regarding to visual modality, it was not true for the other elemental stimulus manipulated on tactual modality. In Experiment 3, behavioral effects tested on the procedures of Experiment 2 were re-evaluated in the subjects received neurotoxic lesions in the amygdala, the dorsal hippocampus, or the ventral hippocampus before conditioning. While amygdaloid lesion significantly attenuated the CPP induced by elemental stimulus, such lesion did not inhibit the CPP induced by the compound stimulus. Lesions on those two hippocampal subareas disrupted the formation of CPP induced by compound stimulus. Regarding the conditioned locomotion, in contrast to what found on CPP, lesion treatment did not produce reliable effect induced by compound stimulus or elemental stimulus. In conclusion, the present findings on two conditioned responses measured support the assumption of Rescorla-Wagner Model on elemental theory. The lesion data indicate that amygdala and hippocampus are differentially involved in conditioned responses induced by psychoactive drug.

Key words: psychopharmacology, amphetamine, conditioned place preference, conditioned locomotion, elemental theory, configural theory, rat.

Identiferoai:union.ndltd.org:CHENGCHI/G0907520031
Creators林姿卿, Lin, Tzy Ching
Publisher國立政治大學
Source SetsNational Chengchi University Libraries
Language中文
Detected LanguageEnglish
Typetext
RightsCopyright © nccu library on behalf of the copyright holders

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