Microstructural observation of epileptic neurons in vitro by atomic force microscopy / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the microstructure of the cell membrane of epileptic neurons using atomic force microscopy (AFM).</p><p><b>METHODS</b>Model of epileptic neurons was established by subjecting the neurons culture for 14 days in vitro to magnesium-free media treatment for 3 h. Patch clamp technique was applied to record the electrophysiological activity of the epileptic neurons. AFM was performed to observe and measure the microstructure of the cell membrane of the epileptic neuron.</p><p><b>RESULTS</b>After a 3-hour treatment with magnesium-free media, the epileptic neurons displayed sustained epileptiform discharge, which continued after the neurons were returned to normal medium culture on day 14. Under AFM scanning size of 80 microm x 80 microm and 2 microm x 2 microm, no obvious difference in the morphology of the cell membrane was noted between epileptic and normal neurons; under the scanning size of 500 nm x 500 nm, small pits occurred in the cell membrane in both groups, but no significant difference was found in the dimension of the pits between the two groups (the diameter and depth of the pits was 114.86-/+9.33 nm and 5.71-/+0.69 nm in epileptic neurons, and 116.4-/+9.13 nm and 5.69-/+0.71 nm in the control neurons, respectively, P>0.05).</p><p><b>CONCLUSION</b>AFM provides a new method for observing neuronal membrane microstructure at nanometer resolutions. No significant alterations occur in the membrane of the neurons after a 3-hour magnesium-free media treatment.</p>

Effect of hyperbaric oxygen on cytochrome C, Bcl-2 and Bax expression after experimental traumatic brain injury in rats / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To explore the effects of hyperbaric oxygen (HBO) treatment on the neuronal apoptosis at an earlier stage and the expressions of Cytochrome C (Cyt C), Bcl-2 (B-cell lymphoma-2 family) and Bax (Bcl-2 associated X protein) in rat brain tissues after traumatic brain injury (TBI).</p><p><b>METHODS</b>Forty adult rats were divided into two groups, i.e., Group A (the rats with untreated TBI) and Group B (rats with HBO treatment after TBI). Sections of brain tissues of these two groups were then detected at 3, 6, 12, 24, 72 hours after TBI by immunohistochemistry and electronmicroscope, respectively.</p><p><b>RESULTS</b>HBO treatment could up-regulate the expression of Bcl-2 within 72 hours, reduce the release of Cyt C from mitochondria, attenuate the formation of dimeric Bax and alleviate the mitochondrial edema within 24 hours after TBI.</p><p><b>CONCLUSIONS</b>HBO treatment can alleviate neuronal apoptosis after TBI by reducing the release of Cyt C and the dimers of Bax and up-regulating the expression of Bcl-2.</p>