Immunofluorescently labeling glutamic acid decarboxylase 65 coupled with confocal imaging for identifying GABAergic somata in the rat dentate gyrus-A comparison with labeling glutamic acid decarboxylase 67.

•Perikaryal GAD67 immunoreactivity is variable in distribution pattern and intensity among cells.•Perikaryal GAD65 immunoreactivity has similar distribution pattern and intensity among cells.•GAD65 is expressed in all hilar CR-, nNOS-, PV- or SOM-positive cells.•A proportion of SOM-positive somata lack perikaryal GAD67 immunoreactivity.•Higher percentage of GAD65-positive somata has perikaryal GABA immunoreactivity than that of GAD67-positive somata.•Inhibition of axonal transport with colchicine improves perikaryal GAD65 labeling, making GABAergic cells more isolatable.