A Novel Approach For Wireless Communication Of In Vivo Data From Freely Moving Research Animals

In vivo electrochemistry has become a fascinating research tool allowing neuroscientists to study the release of oxidizable neurotransmitters, such as dopamine and norepinephrine in the brain of freely moving animals (Garris et al., 1997, J. Neurochem., 68(1): 152–161). The main limitation of this technique is the wired connection from the working electrode at the animal's head to the data acquisition apparatus, thus restricting the animal's freedom of motion. To overcome this limitation, we are designing an electronic device with the capability of performing fast-scan cyclic voltammetry measurements and wirelessly transmitting the recorded data. The device consists of two parts: the base station, which is connected to a PC, and the remote unit, which the rat carries on its back. The base station can wirelessly transmit the potential waveform applied to the working electrode, using the Advanced Audio Distribution Profile (A2DP) protocol. At the remote unit, a capacitance compensation circuit partially removes the capacitive background current present in voltammetric measurements due to charging of the Debye double layer. This increases the device's dynamic range, allowing for the detection of lower neurotransmitter levels. Although the forward telemetry (PC to remote unit) is functional, we have not yet characterized the reverse telemetry (remote unit to PC) in A2DP format. After finalizing the design, the device will be tested in vivo and subsequently employed in behavioral experiments, allowing researchers to obtain data from freely behaving rodents.