Design of a single-channel micropipette amplifier for recording and analysis of action potential

Bioelectric potential are produced as a result of electrochemical activity of a certain class of cells. Electrically they exhibit a resting and action potential. The origin of the action potential lies in the voltage and time-dependent nature of the membrane permabilities to specific ions, notably sodium and potassium. In this thesis, a setup was designed to record the spontaneous action potential from the cerebellum cells. This set up was aimed to observed the effect of anti-psychotic drugs on the cells. The whole steep consist of 1) microelectrode, converting Ionic current in solution into electron currents to the gold wire, 2) the micropipette manipulator, providing insert drift operation into the cells, 3) the amplifier, amplifying the action potential, 4) the high pass filter, suppressing out frequency of 50Hz and its harmonics 5) the A/D converter, and 6) a PC, displaying and storing the action potential. Micropipette is fixed to manipulator and by moving manipulator it is tried to be entered to cell. When entered to cell, action potential which constituted during normal brain actions is observed on oscilloscope and computer screens. If desired, the data can be stored. Later, records are filtered and examined. Using this setup we have successfully recorded the action potential from cerebellar purkinje cells. The experiment was done not only in-vivo but also in-vitro. Key words : Action Potential, Membrane Potential, Micropipette, High Impedance, Noise, Purkinje Cells, Cerebellum VII