Atomic Force Microscopy Studies On The Subcellular Structures Of Cultured Hippocampal Neurons And The Damage Of Free Radicals On Them

To explore the feasibility of AFM to be used in basic biomedicinal studies, we established the technology for the image of the whole HN and studied the subcelluar morphologies and structures of HN and the pathological variations of free radicals on them. Several findings have been made. The traumata of HN were divided into two or three parts by one or two gyri and the up-parts were responsible for the development of the neurites. The morphological and structural observations and measurements of neurosynapses could be achieved and chemical synapses and electrical synapses could be distinguished with AFM. CMJ existed in the gaps between the two closely neighboring HN, italicly going through the gaps. FTC existed between two neurites. There was a center channel in each FTC. The structures of CMJ and FTC could allow the direct communication of the HN cytoplasm through them. The free-radical-damaged HN trama membranes had four main variations: (i) rough-bee-nestle variations; (ii) vast- perforation-like variations; (iii) laminar-sheet-like variations and (iv) round-small-perforation-like variations. The neurite end ruptured off from the neurite and neurite membranes had rough-bee-nestle variations similar to that of the trama membranes. Synapse had three variations after damaged by free radicals: (i) vague fine structures; (ii) separation of pre- and post-synaptic neurites; (iii) vague, uneven and missing of the synaptic separation. The results mentioned above demonstrate that AFM is quite a useful tool for the biological research on HN, capable of simultaneously obtaining whole cell and fine structures, which is not achievable for other microscopy technologies. The methods established in the present work can applied not only to the cell biological studies but also to the physiological, pathological and pharmacological studies.