title: Associative learning down-regulates PKC beta 2- and gamma-immunoreactivity in astrocytes.
abstract: We showed previously that associative learning induced a twofold increase in protein kinase C gamma-immunoreactivity (PKC gamma-ir) in rabbit CA1 pyramidal neurons, whereas subicular neurons remained unchanged. Here, we investigated the effects of associative learning on PKC-positive astrocytes by determining their numerical density in the CA1 region and the subiculum of naive, pseudoconditioned and trace eyeblink conditioned rabbits. Associative learning induced a 70-80% reduction in the number of PKC beta 2- and gamma-positive astrocytes in the CA1 region, but not in the subiculum. No changes were found in the number of PKC alpha- or beta 1-positive astrocytes in either hippocampal subregion. These results suggest a conditioning-specific downregulation of PKC beta 2 and gamma in a subset of astrocytes in a brain region where a simultaneous alteration in neuronal PKC gamma was evident.
authors.affiliation: Department of Cell and Molecular Biology, Northwestern University Medical School, Chicago, IL 60611, USA.
authors.forename: E A
authors.initials: EA
authors.lastname: Van der Zee
authors.forename: M A
authors.initials: MA
authors.lastname: Kronforst-Collins
authors.forename: J F
authors.initials: JF
authors.lastname: Disterhoft
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000378:metabolism*; D015536:Down-Regulation / Q000502:physiology*; D005260:Female; D007150:Immunohistochemistry; D007858:Learning / Q000502:physiology*; D011493:Protein Kinase C / Q000378:metabolism*; D017966:Pyramidal Cells / Q000378:metabolism*; D011817:Rabbits
chemical_list: D011493:Protein Kinase C