| HDAC class | Isoforms expressed in brain | Localization | Species | References |
| Class 1 (Zn2+ dependent) | HDAC 1 | Cortex, caudate/putamen, hippocampus, amygdala SNpc, SNpr, locus coeruleus, corpus callosum, gray matter, white matter | Human, mouse, rat | [21–24] | HDAC 2 | Cortex, caudate/putamen hippocampus, amygdala SNpc, SNpr, locus coeruleus, gray matter, white matter, corpus callosum | Mouse, rat, mouse | [21–24] | HDAC 3 | Cortex, caudate/putamen hippocampus, amygdala SNpc, SNpr, locus coeruleus, globus pallidus | Mouse, rat, human | [21–23] | HDAC 8 | Hippocampus, amygdala SNpc, locus coeruleus | Human, rat | [21, 22, 25] |
| Class IIa (Zn2+ dependent) | HDAC 4 | Cortex, caudate/putamen, hippocampus, amygdala SNpc, SNpr, locus coeruleus, globus pallidus | Human, mouse, rat | [21, 22, 24, 26, 27] | HDAC 5 | Cortex, caudate/putamen, hippocampus, amygdala SNpc, SNpr, locus coeruleus, globus pallidus | Rat, mouse, human | [21, 22, 28] | HDAC 7 | Cortex, caudate/putamen, hippocampus, amygdala SNpc, locus coeruleus, striatum, cerebellum | Rat, mouse, human | [21, 22, 29] | HDAC 9 | Cortex, SNpc, hippocampus, amygdala | Human, mouse, rat | [21, 22, 30, 31] |
| Class IIb (Zn2+ dependent) | HDAC 6 | Cortex, caudate/putamen Hippocampus, amygdala, SNpc, locus coeruleus, cerebellum | Human, mouse, rat | [21, 22, 32] | HDAC 10 | Cortex, amygdala, hippocampus | Human, mouse, rat | [21, 22, 33] |
| Class IV (Zn2+ dependent) | HDAC11 | Cortex, hippocampus, brain stem, cerebellum, diencephalon | Human, mouse, rat | [21, 22, 34] |
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