Acquisition of Computer-Assisted Microscopy Imaging System for Cytogenetic Research and Training in Neuroscience and Reproductive Biology

California State University-Long Beach Foundation, Long Beach CA

Investigators

Abstract

A grant has been awarded to Drs. Lee and Underwood at California State University Long Beach to acquire an imaging system comprised of a fluorescence -capable microscope with motorized stage, CCD camera, computer, and software. This system will provide unbiased stereology capabilities, as well as the ability to 1) visualize immunofluorescent labeled samples; 2) produce 3-dimensional (3-D) reconstructions; and 3) establish image databases accessible via the internet. The goal of Dr. Lee's research is to understand the effects of memory formation and hormones on neurogenesis in the zebra finch hippocampus. The hippocampus of adult birds and mammals retains the capacity for substantial plasticity including the birth of new cells (cytogenesis) and neurons (neurogenesis) in response to a number of environmental influences including learning and memory formation. Dr. Lee recently found that hippocampal cells are also born as a result of injury and collect around the damaged site in the zebra finch brain. Injured brain areas become rich in aromatase as well, an enzyme that converts testosterone to estrogen. Estrogens, in turn, are known to promote differentiation and survival of neurons. These intriguing results are being used to investigate factors influencing cytogenesis and differentiation of new cells into neurons and glia. The aim then is to exploit the ability of the avian hippocampus to respond to environmental influences by training birds on learning tasks, lesioning the hippocampus, injecting them with BrdU (a mitotic marker), and assessing the patterns of cell proliferation, migration, and/or differentiation through the use of immunohistochemical techniques. New BrdU-positive cells will be visualized and counted using the MicroBrightField StereoInvestigator imaging system; double labeling procedures will be used to determine whether new cells are neurons or glia. The goal of Dr. Underwood's research is to understand the relationship between chromosomal abnormalities, a biased sex ratio, and the evolution of "excess" males in the madrone butterfly. Dr. Underwood's research led to the discovery of abnormalities in chromosome pairing during germ cell formation in the madrone butterfly. One subspecies shows a normal complement of 26 bivalents; however, another subspecies shows extreme variations from cell to cell within the same individual. The primary sex ratio of the abnormal subspecies is 75% male while the normal subspecies appears to have a normal sex ratio of 50% males. Butterflies have chromosomal sex determination. Spermatogenesis is extremely abnormal with multivalent chromosomal associations and lagging chromosomes formed during metaphase and anaphase, and the production of micronuclei associated with sperm nuclei. NSF funding will also make it possible to digitize samples obtained from a variety of research projects. This will result in public databases to be used by interested scientists with access to the internet and thus offers an unparalleled opportunity to share information both locally and globally. Individuals from multiple labs will perform procedures remotely thus broadening the scope of research and increasing the opportunity for publication and dissemination of results, while minimizing labor and the number of animals. Beyond the immediate research applications, instructors and their students will be empowered through accessibility to data previously reserved for only a select few. Image databases, accessed as classroom exercises, will expose students to topical and exciting new research as well as train them in the use of 21st century technology thus advancing science and giving them a competitive edge.