Organization of the anterior dorsal ventricular ridge of the lizard Podarcis hispanica: cytoarchitecture and GABA-immunohistochemistry.

The anterior dorsal ventricular ridge (ADVR) of Podarcis hispanica comprises 3 cytoarchitectonic subareas: the rostromedial, caudomedial and lateral ADVR. All 3 subareas showed gamma-aminobutyric (GABA)-like immunoreactivity. GABA-ergic neurons were classified as multipolar (large), stellate (small), bipolar and unipolar cells. Multipolar and stellate GABA-ergic neurons often formed clusters together with GABA-negative cells. Reactive puncta were seen around unreactive somata of the 3 subareas. Like the telencephalic sensory areas of mammals and birds, the ADVR of lizards shows a heterogeneous population of widely distributed GABA-ergic cells that may be the basis for lateral and vertical local inhibition.