Morphology of neuropeptide Y-immunoreactive neurons and fibers in human prefrontal cortex during prenatal and postnatal development

Abstract

The subplate and marginal zone are prominent transient zones of the developing cerebral wall and contain a variety of neuropeptide Y-immunoreactive (NPY-ir) cells. This study investigates morphological maturation as well as regression and/or transformation of NPY-ir neurons in the transient compartments and the cortical plate of the human frontal cortex. The most prominent NPY-ir neuronal population is that of NPY-ir subplate neurons. They exhibited features of all subplate neuronal types reported in Golgi-impregnated sections, with the exception of the pyramidal type. The NPY-ir subplate neurons were the largest of all NPY-ir neurons, but their size regressed rather sharply between 1 month after birth and 2 years. In the NPY-ir subplate neurons and in the NPY-ir Cajal-Retzius cells of the marginal zone, signs of degeneration were observed between 36 postovulatory weeks and about 9 months after birth. Only a few subpial granular layer cells were NPY positive, and they exhibited degeneration-like features, such as cytoplasmic vacuolization, as early as 23 postovulatory weeks. However, NPY-ir neurons continued to be present in the adult counterparts of the subplate and marginal zone, i.e., gyral white matter and layer I, respectively. Across cortical layers II-VI, NPY-ir neurons had the hallmarks of all aspinous short-axon types, with the exception of the neurogliaform and the chandelier neuronal types. Some signs of degeneration were also observed among a few cortical NPY-ir neurons around birth. Unlike the NPY-ir subplate neurons, the general development of cortical NPY-ir neurons did not show an obvious decline in neuronal size and was similar to the pattern in Golgi-staining.

Morphology, molecular phenotypes and distribution of neurons in developing human corpus callosum

“…, 1992), NPY‐positive (Delalle et al. , 1997; Uylings & Delalle, 1997), CalB‐positive (Allendoerfer & Shatz, 1994) and AChE‐reactive (Kostovic & Rakic, 1980; Allendoerfer & Shatz, 1994). Postnatal features and developmental fate of intracallosal neurons were quite similar to those of subplate neurons and their surviving remnants [interstitial neurons in the gyral white matter of the human brain (Kostovic & Rakic, 1980, 1990; Kostović & Jovanov‐Milošević, 2008)].…”

NPY mRNA expression in the prefrontal cortex: Selective reduction in the superficial white matter of subjects with schizoaffective disorder

“…During development of the cerebral cortex, the earliest born cells form the preplate which is subsequently split into the marginal zone (adult layer 1) and the subplate (adult deep layer 6 and superficial white matter) by later born neurons which migrate to become the cortical plate (adult layers 2 - superficial 6) (Kostovic and Rakic 1980). Interestingly, NPY protein is present very early in human development in the preplate neurons underlying DLPFC areas 9 and 46; and in adult human prefrontal cortex, NPY protein is most strongly expressed by neurons located in the residual preplate (layer 1, deep layer 6, and the underlying white matter) (Delalle et al 1997; Uylings and Delalle 1997). Thus, the vulnerable neurons in subjects with schizoaffective disorder, that is those with concurrent psychotic symptoms and a mood disorder, appear to be residual preplate neurons.…”

Where and what is the paralaminar nucleus? A review on a unique and frequently overlooked area of the primate amygdala

“…Like SST, NPY plays a role in neurodevelopmental processes and plasticity (Hansel et al, 2001; Real et al, 2009; Sajdyk et al, 2008; Uylings and Delalle, 1997), and the two peptides are frequently co-localized (McDonald et al, 1995; Schwartzberg et al, 1990). NPY reduces anxiety-like behavior via post-synaptic amygdala receptors in adult rodents (Heilig et al, 1993; Tasan et al, 2010).…”