色质溶解（原文：Chromatolysis），指的是一种神经元细胞的病变过程。

在神经元的细胞质里面具有一些尼氏小体（Nissel bodies，一种组织切片上较深色的块状物），这些尼氏小体其实是粗糙内质网（rough ER），即细胞内负责合成蛋白质的地方。

当神经元受到伤害，细胞骨架会试图重新排列，此时，就能借由光学显微镜观察到尼氏小体暂时性消失，而细胞质颜色变得比较白。等到细胞回复正常状态之后，尼氏小体便会再度出现。

某些类型的神经元细胞（例如：小脑的Purkinje细胞）的色质溶解无法在光学显微镜下看到，但仍可改用电子显微镜或者免疫组织染色等方法来观察。

Chromatolysis is the dissolution of the Nissl bodies in the cell body of a neuron. It is an induced response of the cell usually triggered by axotomy, ischemia, toxicity to the cell, cell exhaustion, virus infections, and hibernation in lower vertebrates. Neuronal recovery through regeneration can occur after chromatolysis, but most often it is a precursor of apoptosis. The event of chromatolysis is also characterized by a prominent migration of the nucleus towards the periphery of the cell and an increase in the size of the nucleolus, nucleus, and cell body. The term "chromatolysis" was initially used in the 1940s to describe the observed form of cell death characterized by the gradual disintegration of nuclear components; a process which is now called apoptosis. Chromatolysis is still used as a term to distinguish the particular apoptotic process in the neuronal cells, where Nissl substance disintegrates.