Disease relevance of Hpca

• To determine factors contributing to the expression of the brain-derived protein, hippocalcin, we mapped its distribution in the brain of Snell pituitary dwarf mutant mice (dw) by immunohistochemical and immunoblot methods [1].

Psychiatry related information on Hpca

• Hippocalcin-deficient mice were also impaired on a discrimination learning task in which they needed to respond to a lamp illuminated on the left or right side to obtain food reinforcement [2].

High impact information on Hpca

• Hippocalcin protects against caspase-12-induced and age-dependent neuronal degeneration [3].
• Hippocalcin is a neuronal calcium binding protein, but its physiological function in brain is unknown [3].
• Neuronal apoptosis inhibitor protein (NAIP), known to interact with hippocalcin, was not altered, but hippocampal neurons from gene-deleted mice were more sensitive to excitotoxicity caused by kainic acid [3].
• Hippocalcin-deficient (-/-) mice displayed no obvious structural abnormalities in the brain including hippocampal formation at the light microscopic level [2].
• Hippocalcin is a member of the neuronal calcium sensor (NCS) protein family that is highly expressed in hippocampal pyramidal cells and moderately expressed in the neurons of cerebral cortex, cerebellum and striatum [2].

Biological context of Hpca

• Deletion of hippocalcin did not result in up-regulation of the hippocalcin-related proteins; neural visinin-like Ca(2+)-binding proteins (NVP) 1, 2, and 3 [2].

Anatomical context of Hpca

• These results indicate that the developmental expression of hippocalcin in the dw brain is affected by the retarded maturation of the neuronal network due to the deficient hormonal state (the lack of growth and thyroid hormones) [1].
• (1) In the hippocampus, hippocalcin immunoreactivity was found in the cell body and dendrites of pyramidal neurons of the normal controls and dw mice, although the intensity of immunoreactivity in the dw mice was lower [1].

Regulatory relationships of Hpca

• (2) In the cerebellum, hippocalcin immunoreactivity was strongly expressed in the Purkinje cell body of both the control and dw mice [1].

Other interactions of Hpca

• Hippocalcin-deficient mice display a defect in cAMP response element-binding protein activation associated with impaired spatial and associative memory [2].

References