Mechanisms underlying adult neurogenesis

很长一段时间以来，人们认为成年人的大脑不能产生新的神经元。在过去的十年里，科学家们发现了许多不同种类的物种的成年大脑，包括人类都能发育出新的神经元。这是神经科学的一个巨大突破，因为这些细胞为治疗影响大脑的疾病提供了巨大的希望，也许能够取代垂死的细胞。据信，这些新的神经元来自大脑内的干细胞。干细胞分裂产生后代，这些后代产生未成熟的神经元，然后最终形成成熟的神经元，这些神经元与其他神经元相连，能够产生电信号。这些新神经元形成连接的地方之一是大脑中一个叫做海马体的地方，它对学习和记忆很重要。为了能够使用新细胞进行治疗，我们需要了解分裂细胞是如何变成神经元的，以及细胞需要什么信号才能成为一个有功能的新神经元？我们还需要更多地了解新细胞的功能。这一建议研究了这两个问题，并特别关注了在未成熟神经元中表达的称为双皮质素的蛋白质如何对新神经元的发育及其在学习和记忆中的作用都很重要。为了做到这一点，我们将利用一种特殊的转基因老鼠，这种老鼠已经被创造出来，没有双皮质素蛋白，看看它们形成了多少新的神经元，并确定它们在学习和记忆等行为中的表现。这些实验的结果将为我们提供新的见解，了解新的神经元是如何形成的，以及它在成人大脑中具有什么功能。

For a long time it was believed that the adult human brain could not make new neurons. Within the last ten years scientists have discovered the adult brain in many different types of species, including humans can develop new neurons. This was a huge breakthrough in neuroscience since these cells provides great hope for treatments that maybe able to replace dying cells for diseases affecting the brain. It is believed that these new neurons come from stem cells within the brain. The stem cells divide to produce progeny, which give rise to immature and then finally the mature neuron that is connected to other neurons and is able to generate electrical signals. One of the places that these new neurons form connections is a place in the brain called the hippocampus, which is important for learning and memory. In order to be able to use the new cells for treatments, we need to understand how the dividing cells turn into neurons and what signals the cell requires in order to become a functional new neuron? We also need to know more about what function the new cells perform? This proposal examines both of these questions and specifically looks at how this protein called doublecortin, which is expressed in the immature neuron may be important to both the development of the new neurons and their role in learning and memory. In order to do this, we will utilize special transgenic mice that have been created without the doublecortin protein and see how many new neurons they are forming and also determine how they perform in behaviors, such as learning and memory. The results from these experiments will provide us with new insight into how the new neuron is formed and what function it has in the adult brain.