本研究以心理興奮性藥物(psychosimulants)引發之行為致敏化作為探討環境與藥物的配對學習如何影響個體長期使用藥物後對藥物的反應。首先於實驗一建立安非他命引發自發活動致敏化基本模式，以及不同的重複注射情境下致敏化的表現，結果顯示經由本實驗操弄注射情境的程序可有效引發在測試箱、飼養籠，和第三處的安非他命致敏化表現，並且致敏化自發活動表現量在測試箱組顯著高於飼養籠組和第三處組。實驗二對致敏化形成歷程中可能與安非他命配對的刺激進行消除，以釐清致敏化形成歷程中連結學習的要素，結果顯示消除程序沒有降低致敏化活動量的效果。實驗三使用中樞注射麩胺酸受體拮抗劑NBQX於依核以影響致敏化的連結學習歷程，結果顯示該操弄可阻斷在飼養籠重複注射安非他命引發的行為致敏化。測試箱組經過該操弄後其致敏化活動量顯著降低但仍有顯著的致敏化活動量表現。實驗四分別破壞前額葉皮質兩處次級區塊以瞭解其在致敏化連結學習歷程中扮演的角色，結果顯示破壞背側前額葉皮質只阻斷在飼養籠注射安非他命所引起的行為致敏化，破壞腹側前額葉皮質只阻斷測試箱組行為致敏化。綜合上述研究結果顯示安非他命引發致敏化的形成深受藥物配對的環境影響而可區分環境相依與環境獨立之行為致敏化，環境相依行為致敏化的行為機制可由場合建立的觀點加以解釋。在依核內之麩胺酸傳導和前額葉皮質次級區塊之功能在兩種行為致敏化上的差異可以反應環境相依和環境獨立行為致敏化的潛在神經機制可能有所不同。 / The present study investigated the neurobehavioral mechanisms of d-amphetamine (AMP) induced behavioral sensitization, with the aim to elucidate the role of associative learning between the context and drug. Experiment 1 compared the sensitization effects of repeated (AMP) conducted in three different contexts by the measurement of locomotion activity. The results showed that behavioral sensitization of locomotion was significantly induced AMP repeatedly injected in each of the contexts. However, the magnitudes of behavioral sensitization were different among those three conditions. The highest degree of sensitized locomotion was observed in the group with repeated AMP conducted in the test box in comparing to the other two groups with drug administration in the home cage and a third place, Experiment 2 was designed to examine the effects of extinction on the injection procedure and the contextual cue on the behavioral sensitization of AMP induced in the test box, the home cage, and a third place. The resu lts clearly indicate all three types of locomotion sensitization were resistant to the manipulation of extinction. Experiment 3 tested the effects of NBQX, a glutamatergic AMPA receptor antagonist, infused into the nucleus accumbens on the establishment of behavioral sensitization of AMP induced in the test box and the home cage. This intra-accumbens NBQX treatment significantly suppressed the formation of behavioral sensitization of AMP induced in the home cage, but not in the test box. Experiment 4 investigated the lesion effects of medial prefrontal cortex (mPFC) on the establishment of behavioral sensitization of AMP induced in the test box and the home cage. Two subareas of the mPFC, dorsal and ventral parts, were lesioned by ibotenic acid. The findings indicated a double dissociation existing in the mPFC subareas for the behavioral sensitization of AMP induced in different contexts. The lesion of ventral mPFC inhibited the formation of behavioral sensitization of AMP induced in the test box, whereas the lesion of dorsal mPFC attenuated the AMP sensitization induced at the home cage. Together, these data suggest that the association of the repeated drug effects pairing to the context is critical for the development of behavioral sensitization. Such sensitization can further be differentiated into the context-depentdent and context-independent forms based on the uniqueness of contextual cue in the environment where drug is administered. Different neural substrates are involved in the establishment of behavioral sensitization of AMP.
| Identifer | oai:union.ndltd.org:CHENGCHI/A2010000179 |
| Creators | 林懷瑠 |
| Publisher | 國立政治大學 |
| Source Sets | National Chengchi University Libraries |
| Language | 中文 |
| Detected Language | English |
| Type | text |
| Rights | Copyright © nccu library on behalf of the copyright holders |
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