Cytoarchitectonic organization and morphology of the cells of hippocampal complex in strawberry finch, Estrilda amandava.

Neurons in the hippocampal complex (dorsomedial forebrain) were described and located following Golgi impregnation. Five fields were recognized in the hippocampal complex: medial and lateral hippocampus, parahippocampal area, central field of the parahippocampal area and crescent field. In the medial hippocampus three layers have been observed: suprapyramidal towards the pial surface, pyramidal at the central and infrapyramidal adjacent to the ventricle. Neurons of the hippocampal complex were classified in to two main cell groups: predominant projection neurons with spinous dendrites and local circuit neurons. Projection neurons were further sub classified into three main types: pyramidal, pyramidal like, and multipolar neurons. In addition to these neurons, monotufted and bitufted neurons were also observed in the medial and lateral hippocampus with low frequency. The pyramidal neurons were dominant neuronal types in the pyramidal layer-II of the medial hippocampus, mixed with pyramidal like and multipolar neurons. Pyramidal and pyramidal-like neurons were found restricted in the pyramidal layer II of the medial hippocampus while the multipolar neurons were uniformly distributed in all subfields of the hippocampal complex. In the lateral hippocampus irregular shaped radial glial cells were present near the ventricular wall and projecting their dendrites towards the pia. Second group of local circuit neurons with local arborization of their projections were present in the medial hippocampus and in parahippocampal area.