Heterochrony of postnatal accumulation of nonphosphorylated heavy‐chain neurofilament by neurons of the cat dorsal lateral geniculate nucleus

• Published in: Journal of comparative neurology (1911) 2021-05, Vol.529 (7), p.1430-1441
• Main Authors: Mikhalkin, Aleksandr, Nikitina, Nina, Merkulyeva, Natalia
• Format: Article
• Language: English
• Subjects: Animals; cat; Cats; critical period; Developmental stages; Female; Geniculate Bodies - cytology; interlaminar differences; Lateral geniculate nucleus; Male; Motion detection; Neurofilament Proteins - analysis; Neurofilaments; Neurogenesis - physiology; Neurons; Neurons - cytology; postnatal development; RRID: AB_2715852; Spatial distribution; Y cells
• ISSN: 0021-9967; 1096-9861
• DOI: 10.1002/cne.25028

Accumulation of the heavy‐chain neurofilaments reflects the maturation status of neuronal structures. The spatial distribution and postnatal developmental dynamic of neurons expressing nonphosphorylated heavy‐chain neurofilaments (labeled by SMI‐32 antibody) were analyzed in the dorsal lateral geniculate nucleus (LGNd) of the cat. Both interlaminar and intralaminar differences in the dynamic of SMI‐32 staining were observed. The following results were obtained: (a) Ascending dorsoventral gradient in the density of SMI‐32 immunopositive (SMI‐32(+)) neurons (the greatest neuronal density in layer Cm, the minor in the top sublayer of layer A). This gradient was most prominent at the earliest stages of postnatal development (1st–2nd weeks) and slowly flattened up to adulthood; (b) Layer A1 exhibits increases in SMI‐32‐positive cells earlier than layer A; (c) The general transient increment in the number and density of SMI‐32(+) neurons around 2–5 postnatal weeks. Since SMI‐32 antibody is considered to be a putative marker for Y cells forming a motion processing stream, we suggest that peculiarities of SMI‐32 staining at geniculate level could reflect the heterogeneity of Y cell subpopulations and the heterochrony of their postnatal maturation. Postnatal development of the SMI‐32 labeling in the dorsal lateral geniculate nucleus (LGNd) of kittens aged 0–123 postnatal days, and in adults (Ad). Left—a representational examples of the SMI‐32 labeling, in kittens aged 0 days, 10 days, and in adult. Right—a number of SMI‐32 immunopositive (SMI‐32(+)) neurons in layers A, A1, and Cm of the LGNd. Different phases of the postnatal development (eyes opening, precritical period, critical period maximum) are marked by colors.