title: Odours stimulate neuronal activity in the dorsolateral area of the hippocampal formation during path integration.
abstract: The dorsolateral area of the hippocampal formation of birds is commonly assumed to play a central role in processing information needed for geographical positioning and homing. Previous work has interpreted odour-induced activity in this region as evidence for an 'olfactory map'. Here, we show, using c-Fos expression as a marker, that neuronal activation in the dorsolateral area of the hippocampal formation of pigeons is primarily a response to odour novelty, not to the spatial distribution of odour sources that would be necessary for an olfactory map. Pigeons exposed to odours had significantly more neurons activated in this area of the brain than pigeons exposed to filtered air with odours removed. This increased activity was observed only in response to unfamiliar odours. No change in activity was observed when pigeons were exposed to home odours. These findings are consistent with non-home odours activating non-olfactory components of the pigeon's navigation system. The pattern of neuronal activation in the triangular and dorsomedial areas of the hippocampal formation was, by contrast, consistent with the possibility that odours play a role in providing spatial information.
authors.affiliation: Unidade de Investigação em Eco-Etologia, ISPA-Instituto Universitário, , Lisboa 1149-041, Portugal, Department of Biological Sciences, Virginia Tech, , Blacksburg, VA 24061-0406, USA, MUHNAC, Universidade de Lisboa, , Lisboa 1250-102, Portugal, Faculty of Science, Department of Zoology, Charles University in Prague, , 128 44 Praha 2, Czech Republic.
authors.forename: P E
authors.initials: PE
authors.lastname: Jorge
authors.forename: J B
authors.initials: JB
authors.lastname: Phillips
authors.forename: A
authors.initials: A
authors.lastname: Gonçalves
authors.forename: P A M
authors.initials: PA
authors.lastname: Marques
authors.forename: P
authors.initials: P
authors.lastname: Nĕmec
mesh_terms: D000818:Animals; D030161:Avian Proteins / Q000235:genetics* / Q000378:metabolism; D010856:Columbidae / Q000502:physiology*; D005819:Genetic Markers; D006624:Hippocampus / Q000502:physiology*; D009812:Odorants; D055696:Olfactory Perception; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics* / Q000378:metabolism; D065854:Spatial Navigation
chemical_list: D030161:Avian Proteins; D005819:Genetic Markers; D016760:Proto-Oncogene Proteins c-fos
keywords: hippocampus; homing; immediate early genes; navigation; olfactory activation; pigeon