Acquisition of a Computer-Assisted Light Microscope

点击翻译按钮获取中文摘要

Purchase of a computer-asslsted light microscope for digital data acquisition and analysis is proposed. The sytem consists of a light microscope, the stage of which is precisely controlled by stepping motors in three dimensions via a PC interface. This control provides a vectorial, threedimensional representation in computer memory, the most efficient means of storing and manipulating ob~ects spanning the scale (from less than micron to several millimeters) of a neuron and all its extended processes. The system will be used to: 1) provide three-dimensional reconstruction of the dendritic trees and and axonal arborizations of selectively stained neurons; and 2) to precisely plot and count selectively stained neurons in a cytoarchitectonic context. Data are acquired using either video or optical overlays. The optical mode uses a miniture cathode ray tube projected directly into the oculars and is best for the highest resolution tracing; the video mode will employ a color camera which will be useful with fluorescent markers. Users will choose between acquisition modes via software switches, even within a session and while tracing the same ob~ect. The software support includes analysis programs for extracting quantitative information such as length, diameter, branching and spine density of processes and for displaying three-dimensional reconstructions. Analysis of images can be performed routinely in the user's own labs, since the software runs on PCs and Macintoshes which make up the user computer base. Also, the station will communicate over an existing Ethemet network to which all users are connected. The network wlll allow rapid data transfer from the station to individual labs, and provide additional analysis options by remote operation of software on existing larger computers in the department.. The station is designed to faciliate ongoing studies of the complex structure and function of nerve cells. A range of projects will be supported, including: 1) determini ng the morphological differences between oxytocin and vasopressin neurons and their neurohypophysial axon arborization as a function of secretory state; 2) understanding corticostriatal axon divergence and convergence, in particular their relation to the dendritic branching of striatal neurons and to cytoarchitectonic boundaries; 3) determining the role of adhesion molecules in axonal guidance; 4) determining whether functional plasticity in somatosensory cortex is accompanied by changes in cortical neuron morphology; 5) understanding the normal organization of neurons in the basal ganglia and the selectivity of cell loss in neurodegenerative disease.