Instrumentation to investigate the magnetoreception of homing pigeons by using applied magnetic fields

The remarkable ability of diverse animals to orientate and navigate during migration and homing over long distances has fascinated scientists for years. However, how the birds sense and process the magnetic field information in their brains is not known [1]. Recent advances have brought new insights into how field direction, intensity, and polarity are neurally encoded by single cells [2]. Several bird species are believed to possess physiological mechanisms that enable them to navigate using the magnetic field. Generally, it is accepted that there are two sensory magnetoreception mechanisms: a light-dependent cytochrome-based magnetic compass and a magnetite-based map [3]. To date, reproducing experimental results has been problematic perhaps related to the difficulty in controlling magnetic field conditions [4]. We describe here a special instrumentation setup of three-dimensional Helmholtz coils, which are used to cancel out the Earth's magnetic field and then generate a field within the range of the Earth's magnetic field, controlled by a specific current source. The magnetic mapping within the volume of the constructed system is measured and compared against magnetic modeling. The visual programming language, LabVIEW (version 2012SP1) of National Instruments (NI)[5], is used to control the system to generate any specific magnetic field condition.