Analysis of differential gene expression supports a role for amyloid precursor protein and a protein kinase C substrate (MARCKS) in long-term memory

2003 ◽  
Vol 17 (5) ◽  
pp. 1073-1081 ◽  
Author(s):  
R. O. Solomonia ◽  
K. Morgan ◽  
A. Kotorashvili ◽  
B. J. McCabe ◽  
A. P. Jackson ◽  
...  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hamish Patel ◽  
Reza Zamani

Abstract Long-term memories are thought to be stored in neurones and synapses that undergo physical changes, such as long-term potentiation (LTP), and these changes can be maintained for long periods of time. A candidate enzyme for the maintenance of LTP is protein kinase M zeta (PKMζ), a constitutively active protein kinase C isoform that is elevated during LTP and long-term memory maintenance. This paper reviews the evidence and controversies surrounding the role of PKMζ in the maintenance of long-term memory. PKMζ maintains synaptic potentiation by preventing AMPA receptor endocytosis and promoting stabilisation of dendritic spine growth. Inhibition of PKMζ, with zeta-inhibitory peptide (ZIP), can reverse LTP and impair established long-term memories. However, a deficit of memory retrieval cannot be ruled out. Furthermore, ZIP, and in high enough doses the control peptide scrambled ZIP, was recently shown to be neurotoxic, which may explain some of the effects of ZIP on memory impairment. PKMζ knockout mice show normal learning and memory. However, this is likely due to compensation by protein-kinase C iota/lambda (PKCι/λ), which is normally responsible for induction of LTP. It is not clear how, or if, this compensatory mechanism is activated under normal conditions. Future research should utilise inducible PKMζ knockdown in adult rodents to investigate whether PKMζ maintains memory in specific parts of the brain, or if it represents a global memory maintenance molecule. These insights may inform future therapeutic targets for disorders of memory loss.


Author(s):  
Maria Gomis-González ◽  
Lorena Galera-López ◽  
Marc Ten-Blanco ◽  
Arnau Busquets-Garcia ◽  
Thomas Cox ◽  
...  

1994 ◽  
Vol 130 (4) ◽  
pp. 394-401 ◽  
Author(s):  
Jianqi Liu ◽  
Arvi I Kahri ◽  
Anna-Maija Teppo ◽  
Raimo Voutilainen

Liu J, Kahri AI, Teppo A-M, Voutilainen R. Regulation of parathyroid hormone gene expression and peptide secretion in human parathyroid cells. Eur J Endocrinol 1994;130:394–401. ISSN 0804–4643 In cell cultures prepared from human parathyroid adenomas, parathyroid hormone (PTH) mRNA expression decreased slowly. During short-term incubations (less than 24), a low calcium concentration (0.5 mmol/l) and protein kinase C activator TPA (12-O-tetradecanoyl phorbol 13-acetate) (160 nmol/l) increased PTH secretion (60%; p <0.05), while a high extracellular calcium concentration (2.5 mmol/l) reduced PTH secretion (60%; p<0.05), The TPA could block the inhibitory effect of a high calcium level on PTH peptide secretion. All these agents had no effect on PTH mRNA accumulation in short-term experiments. In long-term cultures (more than 24 h), a low calcium level increased and a high calcium level reduced both PTH mRNA (85 and 34%; p <0.05) and peptide secretion (140 and 80%; p <0.05), respectively. The TPA reduced PTH mRNA accumulation down to 30% (p<0.05) and PTH secretion down to 14% (p<0.05) in a time- and dose-dependent fashion. The TPA also reversed the stimulatory effect of hypocalcemia on PTH mRNA accumulation and peptide secretion. Protein kinase C inhibitors staurosporine (100 nmol/l) and H-7 (1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride) (50 μmol/l) had similar effects to TPA on PTH gene expression and peptide secretion in long-term cultures. The results support the hypothesis that extracellular calcium regulates PTH mRNA accumulation and PTH secretion via protein kinase C. Raimo Voutilainen, Department of Pathology, PO Box 21 (Haartmaninkatu 3), SF-00014 University of Helsinki, Finland


Nature ◽  
1987 ◽  
Vol 328 (6129) ◽  
pp. 426-429 ◽  
Author(s):  
G.-Y. Hu ◽  
Ø. Hvalby ◽  
S. I. Walaas ◽  
K. A. Albert ◽  
P. Skjeflo ◽  
...  

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