title: Mitochondrial proteins, learning and memory: biochemical specialization of a memory system.
abstract: The enzyme cytochrome c oxidase is a mitochondrial protein complex that plays a crucial role in oxidative metabolism. In the present study we show that amounts of two of its protein subunits (cytochrome c oxidase subunit I [CO-I] and II [CO-II]) are influenced by both learning-independent and learning-dependent factors. Converging evidence has consistently implicated the left intermediate medial mesopallium (IMM) in the chick brain as a memory store for the learning process of visual imprinting. This form of learning proceeds very shortly after chicks have been hatched. In the left IMM, but not in three other brain regions studied, amounts of CO-I and CO-II co-varied: the correlation between them was highly significant. This relationship did not depend on learning. However, learning influenced the amounts of both proteins, but did so only in the left IMM. In this region, amounts of each protein increased with the strength of learning. These findings raise the possibility that the molecular mechanisms involved in the coordinated assembly of cytochrome c oxidase are precociously developed in the left IMM compared to the other regions studied. This precocious development may enable the region to respond efficiently to the oxidative demands made by the changes in synaptic connectivity that underlie memory formation and would allow the left IMM to function as a storage site within hours after hatching.
authors.affiliation: Institute of Chemical Biology, Ilia State University and I. Beritashvili Institute of Physiology, 14 L Gotua Street, Tbilisi 0160, Republic of Georgia.
authors.forename: R O
authors.initials: RO
authors.lastname: Solomonia
authors.forename: N
authors.initials: N
authors.lastname: Kunelauri
authors.forename: E
authors.initials: E
authors.lastname: Mikautadze
authors.forename: D
authors.initials: D
authors.lastname: Apkhazava
authors.forename: B J
authors.initials: BJ
authors.lastname: McCabe
authors.forename: G
authors.initials: G
authors.lastname: Horn
mesh_terms: D000818:Animals; D054022:Cerebrum / Q000033:anatomy & histology / Q000201:enzymology* / Q000254:growth & development; D002645:Chickens; D003576:Electron Transport Complex IV / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D007839:Functional Laterality / Q000235:genetics / Q000502:physiology*; D018392:Genomic Imprinting / Q000502:physiology; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D007858:Learning / Q000502:physiology*; D008568:Memory / Q000502:physiology*; D024101:Mitochondrial Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics / Q000502:physiology
chemical_list: D007527:Isoenzymes; D024101:Mitochondrial Proteins; D021122:Protein Subunits; C117108:cytochrome C oxidase subunit II; D003576:Electron Transport Complex IV