Neuronal classes in the corticoid complex of the telencephalon of the strawberry finch, Estrilda amandava

Abstract

The present study, based on neurohistological techniques (Nissl-staining, Golgi-impregnation), focuses on the cytoarchitecture of the corticoid complex in the strawberry finch, Estrilda amandava. This complex in birds occupies the dorsolateral surface of the telencephalic pallium and remains subdivided into an intermediate corticoid area (CI) and a dorsolateral corticoid area (CDL). The CDL in the strawberry finch is a thin superficial part of the caudal pallium adjoining the medially situated hippocampal formation, whereas the CI is demarcated between the CDL and the parahippocampal area of telencephalon. Neurons of the corticoid complex are classified into three main cell groups: predominant projection neurons, local circuit neurons and stellate neurons. The spinous projection neurons send out distant projecting axons that typically extend several varicose collaterals. Most of these collaterals lie parallel to the ventricle. These neurons are subclassified into pyramidal neurons (localized only in the CI) and multipolar neurons (present in both the CI and CDL). The CDL also possesses small and medium-sized horizontal cells, which are bitufted or multipolar with smooth, moderately branching dendrites. The aspinous local circuit neurons extend short axons that ramify locally. Stellate neurons have sparse spinous dendrites and locally arborizing axons. The corticoid complex of birds corresponds to the lateral cerebral cortex of lizards and to the entorhinal cortex of mammals on the basis of neuronal morphology and bidirectional connections between adjacent areas.

Heterogeneity of spine density in pyramidal neurons of isocortex of mongoose, Herpestes edwardsii (É. Geoffroy Saint‐Hilaire 1818)

“…The pyramidal neurons accounting for at least 70% of the total neocortical population in mammals form the principal element in neocortical circuit. The evolutionary trend of pyramidal neurons' development can be traced right from "extraverted" neurons observed in amphibian pallium; pyramid-like neurons in reptilian cortex (Luis de la Iglasia and Lopez Garcia, 1997;Srivastava et al, 2007Srivastava et al, , 2009b; in hippocampus of homing pigeon, chick (T€ omb€ ol et al, 2000); corticoid complex in strawberry finch (Srivastava et al, 2009a) to the well developed neocortical elements referred by Cajal as "psychic cells" (Nieuwenhuys, 1994). The different aspects of pyramidal cell microanatomy may influence different aspects of cellular, and systems function (Elston and DeFelipe, 2002;Ha€usser and Mel, 2003;Segev et al, 2001).…”

Morphological and Histological Study of the Forebrain (Cerebrum) in a Wild Bird Species (Columba livia domestica) (Gmelin, 1789)

“…The histological structure of dorsolateral corticoid area (DCA), the hippocampus complex and the piriform cortex, in the (C. l. domestica) similar to (12) who studying on Strawberry finch (Estildamandava), it was found to be similar to the current study. The corticoid complex in birds is similar to the lateral cortex of (the reptiles and the mammalian) cortex as indicated by Srivastava (12).…”

Acute stress‐induced neuronal plasticity in the corticoid complex of 15‐day‐old chick, Gallus domesticus

“…The corticoid complex (CC) of birds has been supposed to participate in spatial memory (Atoji & Wild, 2005; Colombo et al, 2001). The CC of birds is present at the dorsolateral surface of the telencephalic pallium which can be divided into two subregions: an intermediate corticoid (CI) area adjacent to the parahippocampal area (APH) and a dorsolateral corticoid (CDL) area (Montagnese et al, 1996; Srivastava, Chand, et al, 2009; Srivastava et al, 2014). At the caudal most level the CI and hippocampal complex (HCC) progressively disappear, while the APH remains visible and limited laterally by the CDL in finches (Montagnese et al, 1996; Srivastava, Chand, et al, 2009) and Indian house crow (Srivastava et al, 2014).…”

“…The CI could constitute a zone of transition between the HA and HCC based on neuronal types (Montagnese et al, 1996; Srivastava, Chand, et al, 2009; Srivastava et al, 2014) and the distribution of neurotransmitters (Krebs et al, 1991), neuropeptides (Erichsen et al, 1991), zinc, and calbindin (Montagnese, Geneser, et al, 1993; Montagnese, Krebs, et al, 1993). The morphological characteristics of neuronal types have been studied by different researchers in the CC of the strawberry finch (Srivastava, Chand, et al, 2009), Indian house crow (Srivastava et al, 2014), and hippocampal and CC of the zebra finch (Montagnese et al, 1996). All of these studies have shown the presence of dominant multipolar neurons, pyramidal neurons, and stellate neurons in both food storing and nonfood storing birds (Montagnese et al, 1996; Srivastava, Chand, et al, 2009; Srivastava et al, 2014).…”

“…The morphological characteristics of neuronal types have been studied by different researchers in the CC of the strawberry finch (Srivastava, Chand, et al, 2009), Indian house crow (Srivastava et al, 2014), and hippocampal and CC of the zebra finch (Montagnese et al, 1996). All of these studies have shown the presence of dominant multipolar neurons, pyramidal neurons, and stellate neurons in both food storing and nonfood storing birds (Montagnese et al, 1996; Srivastava, Chand, et al, 2009; Srivastava et al, 2014). On the basis of afferent and efferent connections of CDL in Pigeon, it is suggested that the CDL region of birds has been considered as a part of the limbic system (Atoji & Wild, 2005) and it may be comparable with the mammalian entorhinal cortex as it is included in the limbic system (Atoji & Wild, 2005).…”