Semicircular Canal Structure during Postnatal Development in Cat and Guinea Pig

Abstract

The gain of the vestibulo-ocular reflex in the cat continues to increase for some time after birth. The reason for this increase is not presently known and one possibility if that it occurs because the cat semicircular canals increase in size. The present study examined this possibility by measuring the radii of curvature (R) of individual semicircular canals and the angular relationships of the semicircular canal planes within a labyrinth in cats and guinea pigs during postnatal growth. It was found that the labyrinths do move apart substantially during postnatal development in both species, but neither the planar relations nor the radii of curvature change significantly during postnatal development. The stability of semicircular canal structure during postnatal skull growth indicates that postnatal developmental changes in canal-related function, such as increased gain in the vestibulo-ocular reflex, in these species are probably due to receptor cell or neural maturational factors.

A Mathematical Model of Human Semicircular Canal Geometry: A New Basis for Interpreting Vestibular Physiology

“…During development, the whole labyrinth migrates from the base of the skull to its final position and orientation in the head (Bast and Anson 1949;Cox and Jeffery 2007;Curthoys et al 1982). As that The mean angle (± standard deviation) between each pair of canal planes from both left and right ears; calculated using the CrossSect weights The average plane equations for the six SCCs; calculated using the CrossSect weights and referenced to the RRSoC In each case, the orientation was chosen to best highlight the attribute being inspected.…”

Aging Effects on Vestibulo-Ocular Responses in C57BL/6 Mice: Comparison with Alteration in Auditory Function

“…Thus, the present findings demonstrate that functional maturation of the mouse vestibular function is delayed in relation to its anatomical maturation. Postnatal developmental changes in VOR responses have been reported in the rat and guinea pig, and these cannot be due to the increasing size of semicircular canals [Curthoys, 1979;Curthoys et al, 1982]. Therefore, functional maturation of the mouse vestibular system may reflect the development of central vestibular networks.…”

Morphometry of the vestibular organ in neonate and adult African mole-rats Cryptomys species

“…The three rodent species examined so far (see Curthoys et al 1982;present paper) are the laboratory rat (with short gestation, altricial, rapidly growing young), the guinea-pig (long gestation, precocial, relatively rapidly growing young), and Cryptomys (long gestation, altricial, very slowly growing young). As stated above, it is only in the rat, and there only in the horizontal semicircular canal, that growth is observed for a short period after birth.…”

“…Ten Kate (1970) has suggested that the increase of the vestibular organ in the fish guarantees constant sensitivity of the animal during its growth. However, the postnatal maturation of the vestibulo-ocular reflex in the cat indicates that even without dimensional changes there are still maturational changes in the receptor and neuronal levels (Curthoys et al 1982). Nothing is known about these maturational changes in Cryptomys.…”

“…While the semicircular canals in fish continue to grow throughout the whole life (Howland and Masci 1973;ten Kate 1970;Werner 1927), they seem to be rather stable in mammals. In the laboratory rat, the horizontal semicircular canal has been shown to grow for 10 days after birth, but in newborn guinea-pigs and cats it is like that of the adult (Curthoys et al 1982). Morphometric data about the development of the human inner ear are very vague.…”