電位依賴型 (voltage-dependent) 鈣離子通道的開啟會誘發許多細胞內生物化學的反應，例如肌肉的收縮、賀爾蒙或神經傳導物質的釋放、以及活化下游基因表達。海馬迴已知於情境及空間學習記憶上扮演一重要角色，而海馬迴各神經迴路皆有α1H T型鈣離子通道高度表達，因此我們假設此型鈣離子通道應於某種程度上參與了學習記憶的形成。本實驗室之前的研究已發現α1H T型鈣離子通道基因剔除小鼠在情境記憶上有學習不良的現象 (Jhe-Wei Shen, 2005)，本篇研究論文中則發現這些基因剔除小鼠在另一種同樣依賴海馬迴學習模式，莫氏水迷宮 (Morris water maze) 中進行的測試後，表現出方向感學習正常。本論文因此進一步利用微矩陣基因晶片比較正常的野生型小鼠與α1H T型鈣離子通道基因剔除小鼠於接受情境痕跡恐懼記憶提取後，左右側海馬迴內基因表達是否有差異。結果顯示在接受情境線索刺激後，與從未接受訓練的對照組相比，正常的野生型小鼠的左、右側海馬迴之表達基因有側極化的現象，僅有少量基因會於左右側海馬迴呈現同樣的表達量。這些訓練後於野生型小鼠的左、右側海馬迴會呈現正調控或是負調控表達，卻於基因剔除小鼠的海馬迴中沒有改變的基因，可能是直接受到經由α1H T型鈣離子通道引入之鈣離子流調控的下游基因。功能性分類後，這些基因大多屬於執行神經活性的功能，也就是與神經塑型有高度相關性。此篇論文研究發現與野生型小鼠相比，α1H T型鈣離子通道基因剔除小鼠於方向感學習上表現正常，但在提取情境恐懼記憶時則有下游基因活化程度變異之情形，這些特異表達基因即可能是導致此種基因剔除小鼠輿情境記憶學習差異的原因。本研究顯示α1H T型鈣離子通道與方向記憶的形成及提取無關，但對於情境痕跡恐懼記憶的提取卻扮演著重要角色。

Voltage-dependent calcium channels (VDCC) trigger many intracellular biochemical events, including muscle contraction, gene expression or hormones and neurotransmitter secretion. Among all VDCCs, the T-type Ca2+ channel α1H subunit encoded by Cav3.2 gene is highly expressed in the hippocampus, which is correlated with contextual learning and spatial memory. Our previously research (Jhe-Wei Shen, 2005) showed that α1H KO mice are impaired in contextual trace fear conditioning, step-down and step-through avoidance tests but functionally normal in locomotor activity and auditory trace fear conditioning. Whether α1H T-type Ca2+ channels are also important to other hippocampal-dependent learning or not is still unknown. In this thesis, α1H KO mice were used to perform Morris water maze and their learning appeared to be normal. Besides, using genome wide microarray analysis for retrieval of contextual fear, asymmetrical gene expression patterns of bilateral hippocampi in training WT groups versus na��ve groups were observed. A cluster of genes that only revealed differential expression in WT group but not in KO group after contextual test may directly modulated by calcium influx via α1H T-type Ca2+ channels. Most of them are functionally related to neuronal activities and neural plasticity. My results showed that α1H KOs, though impaired in contextual fear conditioning, learned as well as WTs on spatial learning. In addition, differentially expressed genes had been screened clustered for retrieval of contextual fear. Some of them could be identified to be modulated by α1H T-type Ca2+ channels. My research indicates that α1H T-type Ca2+ channel independent with formation and retrieval of spatial learning but plays an important role in retrieving contextual trace fear conditioning.

Abstract I
中文摘要 II
Index III
Introduction 1
Aim 8
Materials and Methods 9
Results 15
Discussion 19
Figures 23
Tables 45
References 53

References
Abel, T., Nguyen, P.V., Barad, M., Deuel, T.A., Kandel, E.R., Bourtchouladze, R., 1997. Genetic demonstration of a role for PKA in the late phase of LTP and in hippocampus-based long-term memory. Cell. 88, 615-26.
Abel, T., Lattal, K.M., 2001. Molecular mechanisms of memory acquisition, consolidation and retrieval. Curr Opin Neurobiol. 11, 180-7.
Alberini, C.M., 2009. Transcription factors in long-term memory and synaptic plasticity. Physiol Rev. 89, 121-45.
Alvarez, P., Zola-Morgan, S., Squire, L.R., 1994. The animal model of human amnesia: long-term memory impaired and short-term memory intact. Proc Natl Acad Sci U S A. 91, 5637-41.
Alvarez, P., Zola-Morgan, S., Squire, L.R., 1995. Damage limited to the hippocampal region produces long-lasting memory impairment in monkeys. J Neurosci. 15, 3796-807.
Cammarota, M., Bevilaqua, L.R., Barros, D.M., Vianna, M.R., Izquierdo, L.A., Medina, J.H., Izquierdo, I., 2005. Retrieval and the extinction of memory. Cell Mol Neurobiol. 25, 465-74.
Carbone, E., Lux, H.D., 1984. A low voltage-activated, fully inactivating Ca channel in vertebrate sensory neurones. Nature. 310, 501-2.
Chen, C.C., Lamping, K.G., Nuno, D.W., Barresi, R., Prouty, S.J., Lavoie, J.L., Cribbs, L.L., England, S.K., Sigmund, C.D., Weiss, R.M., Williamson, R.A., Hill, J.A., Campbell, K.P., 2003. Abnormal coronary function in mice deficient in alpha1H T-type Ca2+ channels. Science. 302, 1416-8.
Corkin, S., 2002. What's new with the amnesic patient H.M.? Nat Rev Neurosci. 3, 153-60.
D'Hooge, R., De Deyn, P.P., 2001. Applications of the Morris water maze in the study of learning and memory. Brain Res Brain Res Rev. 36, 60-90.
Dolphin, A.C., 2006. A short history of voltage-gated calcium channels. Br J Pharmacol. 147 Suppl 1, S56-62.
Eichenbaum, H., Stewart, C., Morris, R.G., 1990. Hippocampal representation in place learning. J Neurosci. 10, 3531-42.
Frankland, P.W., Ding, H.K., Takahashi, E., Suzuki, A., Kida, S., Silva, A.J., 2006. Stability of recent and remote contextual fear memory. Learn Mem. 13, 451-7.
Holland, P.C., Bouton, M.E., 1999. Hippocampus and context in classical conditioning. Curr Opin Neurobiol. 9, 195-202.
Iftinca, M.C., Zamponi, G.W., 2009. Regulation of neuronal T-type calcium channels. Trends Pharmacol Sci. 30, 32-40.
Kandel, E.R., 2001. The molecular biology of memory storage: a dialog between genes and synapses. Biosci Rep. 21, 565-611.
Kenney, J.W., Gould, T.J., 2008. Modulation of hippocampus-dependent learning and synaptic plasticity by nicotine. Mol Neurobiol. 38, 101-21.
Kubota, M., Murakoshi, T., Saegusa, H., Kazuno, A., Zong, S., Hu, Q., Noda, T., Tanabe, T., 2001. Intact LTP and fear memory but impaired spatial memory in mice lacking Ca(v)2.3 (alpha(IE)) channel. Biochem Biophys Res Commun. 282, 242-8.
Lee, S.H., Choi, J.H., Lee, N., Lee, H.R., Kim, J.I., Yu, N.K., Choi, S.L., Kim, H., Kaang, B.K., 2008. Synaptic protein degradation underlies destabilization of retrieved fear memory. Science. 319, 1253-6.
Li, Y., Mu, Y., Gage, F.H., 2009. Development of neural circuits in the adult hippocampus. Curr Top Dev Biol. 87, 149-74.
Livak, K.J., Schmittgen, T.D., 2001. Analysis of relative gene expression data using real-time quantitative PCR and the 2(-Delta Delta C(T)) Method. Methods. 25, 402-8.
Logue, S.F., Paylor, R., Wehner, J.M., 1997. Hippocampal lesions cause learning deficits in inbred mice in the Morris water maze and conditioned-fear task. Behav Neurosci. 111, 104-13.
Maren, S., 2008. Pavlovian fear conditioning as a behavioral assay for hippocampus and amygdala function: cautions and caveats. Eur J Neurosci. 28, 1661-6.
McKay, B.E., McRory, J.E., Molineux, M.L., Hamid, J., Snutch, T.P., Zamponi, G.W., Turner, R.W., 2006. Ca(V)3 T-type calcium channel isoforms differentially distribute to somatic and dendritic compartments in rat central neurons. Eur J Neurosci. 24, 2581-94.
McKinney, B.C., Murphy, G.G., 2006. The L-Type voltage-gated calcium channel Cav1.3 mediates consolidation, but not extinction, of contextually conditioned fear in mice. Learn Mem. 13, 584-9.
Mikesova, E., Barankova, L., Sakmaryova, I., Tatarkova, I., Seeman, P., 2006. Quantitative multiplex real-time PCR for detection of PLP1 gene duplications in Pelizaeus-Merzbacher patients. Genet Test. 10, 215-20.
Milekic, M.H., Alberini, C.M., 2002. Temporally graded requirement for protein synthesis following memory reactivation. Neuron. 36, 521-5.
Perez-Reyes, E., 2003. Molecular physiology of low-voltage-activated t-type calcium channels. Physiol Rev. 83, 117-61.
Postma, A., Kessels, R.P., van Asselen, M., 2008. How the brain remembers and forgets where things are: the neurocognition of object-location memory. Neurosci Biobehav Rev. 32, 1339-45.
Quinn, J.J., Oommen, S.S., Morrison, G.E., Fanselow, M.S., 2002. Post-training excitotoxic lesions of the dorsal hippocampus attenuate forward trace, backward trace, and delay fear conditioning in a temporally specific manner. Hippocampus. 12, 495-504.
Ramos, C., Robert, B., 2005. msh/Msx gene family in neural development. Trends Genet. 21, 624-32.
Riedel, G., Micheau, J., Lam, A.G., Roloff, E.L., Martin, S.J., Bridge, H., de Hoz, L., Poeschel, B., McCulloch, J., Morris, R.G., 1999. Reversible neural inactivation reveals hippocampal participation in several memory processes. Nat Neurosci. 2, 898-905.
Suzuki, A., Josselyn, S.A., Frankland, P.W., Masushige, S., Silva, A.J., Kida, S., 2004. Memory reconsolidation and extinction have distinct temporal and biochemical signatures. J Neurosci. 24, 4787-95.
Takekuni, K., Ikeda, W., Fujito, T., Morimoto, K., Takeuchi, M., Monden, M., Takai, Y., 2003. Direct binding of cell polarity protein PAR-3 to cell-cell adhesion molecule nectin at neuroepithelial cells of developing mouse. J Biol Chem. 278, 5497-500.
Talley, E.M., Cribbs, L.L., Lee, J.H., Daud, A., Perez-Reyes, E., Bayliss, D.A., 1999. Differential distribution of three members of a gene family encoding low voltage-activated (T-type) calcium channels. J Neurosci. 19, 1895-911.
Vannahme, C., Schubel, S., Herud, M., Gosling, S., Hulsmann, H., Paulsson, M., Hartmann, U., Maurer, P., 1999. Molecular cloning of testican-2: defining a novel calcium-binding proteoglycan family expressed in brain. J Neurochem. 73, 12-20.
Werner, N.S., Meindl, T., Engel, R.R., Rosner, R., Riedel, M., Reiser, M., Fast, K., 2009. Hippocampal function during associative learning in patients with posttraumatic stress disorder. J Psychiatr Res. 43, 309-18.
Xu, Y., Zhou, Y.L., Erickson, R.L., Macdougald, O.A., Snead, M.L., 2007. Physical dissection of the CCAAT/enhancer-binding protein alpha in regulating the mouse amelogenin gene. Biochem Biophys Res Commun. 354, 56-61.
Zhou, Y.L., Lei, Y., Snead, M.L., 2000. Functional antagonism between Msx2 and CCAAT/enhancer-binding protein alpha in regulating the mouse amelogenin gene expression is mediated by protein-protein interaction. J Biol Chem. 275, 29066-75.