part_of part of part of has soma location has soma location expresses expresses granule cell GABAergic neuron striatum neuron Islands of Calleja granule cell In Rhesus macaques, the Island of Calleja granule cell type has been noted to have enriched gene expression of CPNE4. A GABAergic neuron that resides in the islands of calleja and shows the cytoarchitectural and molecular features characteristic of this granule-like cell population. In mice and primates, it expresses D1 and D3 dopamine receptors (Drd1; Drd3), GABAergic markers (GAD1/2) and form densely packed granule cell clusters in the olfactory tubercle within the ventral striatum. Moreover it receives dense dopaminergic input from the VTA, and functionally associated with self-grooming behaviors and depression-like behaviors. D(1A) dopamine receptor island of Calleja ventral striatum