Postnatal development of substance-P immunoreactivity in the rat superior colliculus

Abstract

Immunocytochemical techniques have been used to examine the distribution of substance-P (SP)-labeled neurons in the superior colliculus of rats from birth to adulthood. At birth, there are almost no SP-immunopositive neurons in the tectum. A small number of SP neurons appear over the next several days. However, the vast majority of SP neurons appear between P9 and P10, and by P12 have attained adult-like numbers and distribution. Neurons are confined to the superficial layers of the colliculus, specifically the upper two-thirds of the stratum griseum superficiale (SGS). There is no indication of a differential developmental sequence along rostrocaudal or mediolateral axes. Neuronal types can be distinguished as early as P6 and include horizontal, vertical, and multipolar cells.Substance-P-immunoreactive axons and boutons are also present in the superior colliculus at birth, and are for the most part confined to the deep layers. Boutons are generally of the en-passant type. The density of labeled axons and boutons increases progressively, and by P10 there is an almost adult-like lamination and patchiness. In the adult, labeled axons and boutons are most dense in the stratum opticum and stratum griseum intermedium. Bridges of dorsoventrally oriented labeled axons span the relatively label-poor stratum album intermedium. SP label in the stratum griseum profundum is dense and patchy, and there is also dense label in the stratum album profundum bordering the periaqueductal grey.The role of substance-P-labeled neurons in the superior colliculus is still a matter of speculation. The findings of this study indicate that SP neurons may play a role in intrinsic collicular circuitry.

Molecular features distinguish ten neuronal types in the mouse superficial superior colliculus

“…Individual surveys of sSC markers include various neuropeptides and calcium binding proteins identified by antibodies (Laemle and Feldman, ; Okamoto et al, ; Behan et al, ; Ogawa‐Meguro et al, ; Arai et al, ; Cork et al, ; Soares‐Mota et al, ). Given that neuropeptides and calcium binding proteins play important roles in diverse biological phenomena, we reexamined nine markers to comprehensively determine their expression patterns.…”

“…Historically, molecular studies of the mammalian SC and avian or amphibian tectum have focused on the development of retinotopic map formation or eyespecific segregation (Constantine-Paton et al, 1990;McLaughlin and O'Leary, 2005;Feldheim and O'Leary, 2010). However, individual surveys of a small number of molecules produced only a limited cell type classification (Laemle and Feldman, 1985;Okamoto et al, 1990;Behan et al, 1992;Mize et al, 1992;Ogawa-Meguro et al, 1992;Arai et al, 1993;Behan et al, 1993;Cork et al, 1998Cork et al, , 2000Harvey et al, 2001;Soares-Mota et al, 2001). Understanding the diversity of sSC neurons requires a systematic analysis of multiple molecular families.…”

The mouse pulvinar nucleus: Organization of the tectorecipient zones

“…Where examined, these two stains overlap to a great extent, perhaps due to involvement of acetylcholinesterase in the hydrolysis of substance P (Goebel and Pourcho, 1992a, 1992b). Studies in the cat and rat suggest that the expression of substance P in tectopulvinar pathways is developmentally regulated, and influenced by visual input (Behan et al, 1993; Miguel-Hidalgo et al, 1990, 1991). The mouse is an ideal model to further define the role of substance P in tectopulvinar pathways by using transgenic lines, optogenetics, and/or designer receptors exclusively activated by designer drugs (DREADD) to manipulate substance P pathways and characterize any resulting behavioral effects.…”

Honeycomb-like structure of the intermediate layers of the rat superior colliculus, with additional observations in several other mammals: AChE patterning

“…The idea of collicular compartmentalization has been reinforced by the neurochemical finding of a regular distribution of a number of neuroactive substances in the intermediate layers such as somatostatin (Spangler and Morlay, 1987), enkephalin (Graybiel et al, 1984;MiguelHidalgo et al, 1989;Mize, 1989;Graybiel and Illing, 1994), cytochrome oxidase (Sandell, 1984;Wiener, 1986), choline acetyltransferase (Ross and Godfrey, 1985;Beninato and Spencer, 1986;Hall et al, 1989;Hashikawa, 1989;Illing, 1990;Henderson and Sheriff, 1991;Jeon and Mize, 1993), parvalbumin , substance P (Miguel-Hidalgo et al, 1989;Behan et al, 1995), hexokinase (Sandell, 1984), and others (Illing, 1996).…”