Changes in intracellular calcium concentration and mitochondrial potential in primary cultures of rat brain cells in acute mechanical injury

Abstract

Background. In vitro modeling of traumatic brain injury helps clarifying pathological mechanisms responsible for cell death or their subsequent dysfunction in detail, which is difficult to accomplish in vivo. Aim. To determine changes in intracellular free Ca²⁺ concentration ([Ca²⁺]_i) and mitochondrial potential (ΔΨ_m) in a primary neuroglial culture during infliction of a mechanical injury (scratch). Methods and materials. Changes in [Ca²⁺]_i and ΔΨ_m in the primary neuroglial culture from the cerebral cortex of 1—2 day old rats were monitored using a fluorescence microscopy technique. Measurements were performed in 11—14-day old cultures. Results. Neurotrauma resulted in a sharp increase in [Ca²⁺]_i and a synchronous profound drop of ΔΨ_m. These changes affected cells located not farther than 100 μm from the boundary of the injury. Inhibition of NMDA-type ionotropic glutamate receptors with MK-801 reduced by approximately 8.5 times the proportion of neurons, which indicated a high [Ca²⁺]_i rise. Conclusion. Ca²⁺ influx into cells during mechanical injury of the primary neuroglial culture occurs predominantly through NMDA-channels and perhaps partially through ATP-activated channels.