Hierarchical Development of the Primate Visual Cortex, as Revealed by Neurofilament Immunoreactivity: Early Maturation of the Middle Temporal Area (MT)

Abstract

It has been suggested that the development of the cerebral cortex reflects its hierarchical organization, with the primary sensory areas being the first to reach structural and functional maturity, and higher-order association areas being the last. In the present study, we labelled the cortex of New World marmoset monkeys of late fetal and early postnatal ages with an antibody to non-phosphorylated neurofilament, a marker of structural maturation of a subset of pyramidal cells. Supporting the concept of hierarchical maturation, we found that at birth labelled cells were found in the primary visual, auditory and somatosensory areas, but not in most other cortical fields. The exception was visual area MT, which revealed an infragranular pattern of labelling comparable to the one observed in the primary areas, as well as some supragranular staining. In MT, an adult-like pattern of labelled cells, including both supragranular and infragranular layer neurons, emerged within the first postnatal month. In comparison, the development of other extrastriate areas was delayed, with the first signs of neurofilament staining not present until the third week. The present results support the concept of MT as another primary visual area, an idea previously advanced on the basis of functional and anatomical evidence.

Impact of blindness onset on the functional organization and the connectivity of the occipital cortex

“…The existence of a restricted time window for blindness to lead to functionally specific cross-modal plasticity in right dorsal regions is consistent with previous evidence of early structural (Gogtay et al, 2004;Bourne and Rosa, 2006;Flom et al, 2009) and functional (Ellemberg et al, 2002;Fine et al, 2003;Gregory, 2003;Maurer et al, 2005) maturation of these regions. Our results also support the recent findings of Bedny et al (2010) who, focusing on hMT + /V5, reported that this region reacts more strongly to an auditory condition with higher motion content (approaching footsteps) than to a condition with lower motion content (tones increasing in intensity), in early-onset blind individuals but not in a group of five late-onset blind individuals.…”

Chemoarchitecture of the middle temporal visual area in the marmoset monkey (Callithrix jacchus): Laminar distribution of calcium‐binding proteins (calbindin, parvalbumin) and nonphosphorylated neurofilament

“…This relatively direct afference has been hypothesized to mediate residual vision after lesions of the geniculostriate pathway (Rodman et al, 2001). There are, in fact, several intriguing parallels between area MT and the primary sensory areas of the primate cortex, suggesting that, from developmental and evolutionary points of view, area MT could also be considered a "primary visual area" (Bourne and Rosa, 2006). The present study reports on the distribution of cells expressing different immunocytochemical markers in area MT of the marmoset, a species of New World monkey.…”

Visual Pathway for the Optokinetic Reflex in Infant Macaque Monkeys

“…The long time course might correspond to the prolonged process of myelination and local circuit formation in primate cortex as revealed histologically and with magnetic resonance imaging (Rodman, 1994;Condé et al, 1996;Gogtay et al, 2004;Kourtzi et al, 2006;Malkova et al, 2006;Deoni et al, 2011). Interestingly, area MT like primary sensory areas shows adult-like immunohistochemistry within the first postnatal month (Bourne and Rosa, 2006). In the motor system conduction velocity becomes adult-like only at 11 months of age (Armand et al, 1994).…”