title: Extracellular recordings reveal absence of magneto sensitive units in the avian optic tectum.
abstract: There is a consensus that birds detect the earth's magnetic field and use some of its features for orientation and homing purposes. Since the late 1960s, when the first solid behavioral evidence of magnetoreception was obtained, much research has been devoted to describing the ethological aspects of this behavior. The neurophysiological basis of magnetoreception has been much less studied, although a frequently cited 1986 report described a high prevalence (70 %) of magneto-sensitive neurons in the pigeon optic tectum with high signal-to-noise ratios (Semm and Demaine, J Comp Physiol A 159:619-625, 1986). Here, we repeated these neurophysiological experiments using anesthetized as well as awake pigeons and new recording techniques. Our data indicate that magneto-sensitive units do not exist in the avian tectum.
authors.affiliation: Department of Biology, Facultad de Ciencias, Universidad de Chile, Santiago, Chile, edgardo.ramirez@gmail.com.
authors.forename: Edgardo
authors.initials: E
authors.lastname: Ramírez
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Marín
authors.forename: Jorge
authors.initials: J
authors.lastname: Mpodozis
authors.forename: Juan-Carlos
authors.initials: JC
authors.lastname: Letelier
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000528:radiation effects*; D000818:Animals; D010856:Columbidae; D004307:Dose-Response Relationship, Radiation; D007649:Ketamine / Q000494:pharmacology; D060526:Magnetic Fields; D008280:Magnetics; D009474:Neurons / Q000187:drug effects / Q000528:radiation effects*; D010775:Photic Stimulation; D018709:Statistics, Nonparametric; D013477:Superior Colliculi / Q000166:cytology*; D014851:Wakefulness
chemical_list: D007649:Ketamine