Long-term recording of the touch-evoked action potentials in awake and pentobarbital-anesthetized rats

To understand higher functions of the brain such as memory, learning, and cognition and network connection of the brain, electrophysiological recordings in conscious animals are indispensable. Hence, recording neuronal signals in conscious animals is a trend and is the kernel technique to reveal authentic brain function. Animal studies in our laboratory are moving from anesthetic state to conscious model. This thesis is a pilot study for this goal. In this study, evoked action potentials were recorded in the somatosensory cortex (S1) of rats both in conscious and anesthetic states. Homemade micro-wire electrodes were implanted in S1 for one month. Mechanical stimuli were applied to induce neuronal action potentials (APs). Comparing these APs in both states, the signal-to-noise ratio (SNR) and peak-to-peak amplitude in anesthetic state were larger than those in conscious state (p<0.001). The latency of APs shows no significant difference between these states (p>0.05). After long-term observation, it is suggested that neuronal signals can be stably recorded by these homemade micro-wire electrodes.