The development of sensorimotor reflexes in albino mice; albino rats and black‐hooded rats

Abstract

The present investigation aimed to show the differences in the development of sensorimotor reflexes and their relationship to the structural changes in spinal cord, cerebellum and cerebral cortex in three rodent species. The three species are albino rats (A-Rats), black-hooded rats (B-Rats) and albino mice. The development of selected reflexes was examined from day (D1) to D21. The structural changes were investigated at D7, D14, and D21. The following reflexes were analyzed: fore-limb/hind-limb grasp, surface body righting, fore-limb hopping, chin tactile placing, visual placing and body righting in the air. The developmental pattern of the reflexes was different in three rodent species. Although the black-hooded rats and albino rats belong to the same species, they are different in their appearance and developmental pattern. The development of external features and sensorimotor reflexes appeared earlier in mice than in A-Rats and B-Rats. At D7, differentiation of neurons was observed in the spinal cord while in cerebellum and cerebrum the neurons were found to be undifferentiated. At D14 and D21, the differentiated neurons were observed in spinal cord, cerebellum and cerebrum. Our data indicate that the developmental pattern of the reflexes in rodents may not be species specific but may be related to the animal strain.

Prepubertal Fischer 344 rats display stronger morphine‐induced taste avoidance than prepubertal Lewis rats

“…As described, prepubescent F344 rats acquired the avoidance at a faster rate and to a stronger degree than animals in the LEW strain, a pattern that paralleled the results of Experiment 1 with adults under the modified deprivation procedure and those previously reported with adults in these strains (Davis et al, 2012;Gomez-Serrano et al, 2009;Lancellotti et al, 2001). The present results demonstrate that differences in morphine-induced taste avoidance are evident as early as prepubescence and are developmentally stable, suggesting that these differences are highly heritable (for other developmental strain assessments, see Allam, 2012;Fairless et al, 2012;Farid et al, 2000;Moore et al, 2011Moore et al, , 2013Paylor et al, 1996;Satinder, 1981;Sinaiko & Mirkin, 1974;Tonkiss et al, 1992;Vogl et al, 1994;Wilking et al, 2012).…”

“…Specifically, there were no differences between the strains across various doses tested in late adolescence and adulthood. However, in early adolescence C3H/Ibg subjects were more sensitive than the C57bl/6j strain at 10 mg concentration while in middle adolescence C3H/Ibg subjects emitted less behavior than C57bl/6j mice at 20 and 30 mg concentrations (for other examples of developmental differences in strain comparisons, see Allam, 2012;Fairless et al, 2012;Farid, Martinez, Geyer, & Swerdlow, 2000;Moore, Forrest, & Boehm, 2013;Moore, Linsenbardt, Melón, & Boehm, 2011;Paylor, Baskall-Baldini, Yuva, & Wehner, 1996;Satinder, 1981;Sinaiko & Mirkin, 1974;Tonkiss, Shultz, & Galler, 1992;Vogl, Atchley, & Xu, 1994).…”

Low and moderate prenatal ethanol exposures of mice during gastrulation or neurulation delays neurobehavioral development

“…Some of the discrepancies noted in the comparisons above may be due to inter-species differences in sensorimotor development, which occur earlier in mice than rats, thus possibly shifting the time of greatest vulnerability (Allam and Abo-Eleneen, 2012); differences in treatment time during neurulation (ours was on GD8:6h and GD8:10h, Enders et al treated at an unspecified time on GD8); and higher BECs due to higher ethanol dose and intraperitoneal delivery. Overall, these findings collectively confirm that ethanol treatment during the earliest stages of brain development results in delayed sensorimotor and physical development.…”

Buriti oil (Mauritia flexuosa L.) negatively impacts somatic growth and reflex maturation and increases retinol deposition in young rats

“…During this phase, structures are major organs in the state of rapid growth, especially brain, and nutritional support is even more essential for this tissue (Morgane et al, 1993). Cerebellum has its development peak during lactation and reflex maturation is directly related to the continuous differentiation and maturation of cerebellar neurons (Allam and Albo‐Eleneen, 2012).…”