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

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A grant has been awarded to Drs. Lee and Underwood at California StateUniversity 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 memoryformation and hormones on neurogenesis in the zebra finch hippocampus. Thehippocampus of adult birds and mammals retains the capacity for substantialplasticity including the birth of new cells (cytogenesis) and neurons(neurogenesis) in response to a number of environmental influences includinglearning and memory formation. Dr. Lee recently found that hippocampal cellsare also born as a result of injury and collect around the damaged site in thezebra finch brain. Injured brain areas become rich in aromatase as well, anenzyme that converts testosterone to estrogen. Estrogens, in turn, are knownto promote differentiation and survival of neurons. These intriguing resultsare being used to investigate factors influencing cytogenesis anddifferentiation of new cells into neurons and glia. The aim then is to exploitthe ability of the avian hippocampus to respond to environmental influences bytraining birds on learning tasks, lesioning the hippocampus, injecting themwith BrdU (a mitotic marker), and assessing the patterns of cell proliferation,migration, and/or differentiation through the use of immunohistochemicaltechniques. New BrdU-positive cells will be visualized and counted using theMicroBrightField StereoInvestigator imaging system; double labeling procedureswill be used to determine whether new cells are neurons or glia. The goal of Dr. Underwood's research is to understand the relationshipbetween chromosomal abnormalities, a biased sex ratio, and the evolution of"excess" males in the madrone butterfly. Dr. Underwood's research led to thediscovery of abnormalities in chromosome pairing during germ cell formation inthe madrone butterfly. One subspecies shows a normal complement of 26bivalents; however, another subspecies shows extreme variations from cell tocell within the same individual. The primary sex ratio of the abnormalsubspecies is 75% male while the normal subspecies appears to have a normal sexratio of 50% males. Butterflies have chromosomal sex determination.Spermatogenesis is extremely abnormal with multivalent chromosomal associationsand lagging chromosomes formed during metaphase and anaphase, and theproduction of micronuclei associated with sperm nuclei. NSF funding will also make it possible to digitize samples obtained from avariety of research projects. This will result in public databases to be usedby interested scientists with access to the internet and thus offers anunparalleled opportunity to share information both locally and globally.Individuals from multiple labs will perform procedures remotely thus broadeningthe scope of research and increasing the opportunity for publication anddissemination of results, while minimizing labor and the number of animals.Beyond the immediate research applications, instructors and their students willbe empowered through accessibility to data previously reserved for only aselect few. Image databases, accessed as classroom exercises, will exposestudents to topical and exciting new research as well as train them in the useof 21st century technology thus advancing science and giving them a competitiveedge.