Fig. 11.

Summary of neurophysiology of avian magnetoreception research. The search for the neural basis of magnetoreception used two different tools: extracellular recordings and activity markers (c-fos, ZENK). Positive electrophysiological results have been reported in: the pineal gland (PG) (Semm 1983), the trigeminal ganglion (Semm and Beason 1990a, b), the superior (VS) and lateral (VeL) vestibular nuclei (Wu and Dickman 2012), the nucleus of the basal optic root (nBOR) (Semm and Demaine 1986) and the optic tectum (Semm and Demaine 1986). Negative electrophysiological results have been reported in the optic tectum, the nucleus isthmi pars parvocellularis (Ipc), the entopallium and the hippocampus (Hp) (data from Rose 2005 and Ramirez 2011). Positive evidence derived from activity markers has been found in the Wulst, and subdivisions of the hyperpallium (HD, DMP) (Mouritsen et al. 2005; Heyers et al. 2007, 2010; Mouritsen and Hore 2012; Mouritsen 2013). Also subdivisions of the trigeminal nucleus labeling (PrV: Principal sensory nucleus of the trigeminal nerve, SpV: Spinal trigeminal nucleus) (data from Heyers et al. 2010; Wu and Dickman 2011). Some important nuclei, because of their physiology and position in the visual pathways, have not been explored: the nucleus rotundus (Rt), the nucleus of the dorsal thalamus (DLA) and the isthmo optic nucleus (IOn)