AIM: To explore whether histamine can regulate the expression of early growth response factor-1( Egr-1) in the cerebral cortex astrocytes. METHODS: Normal wild-type( WT) mice,histidine decarboxylase knockout( HDC-KO) mice and histamine treated HDC-KO mice were sacrificed for extracting the total RNA of the cerebral cortex.Primary cultured rat cortical astrocytes were treated with histamine at concentrations of 10~(- 8),10~(- 7),10~(- 6),10~(- 5)or 10~(- 4)mol / L for 15,30,60,120 or 240 min. H_1 or H_2recep...