IN the course of investigations on the working of the respiratory mechanism in cats, dogs, rabbits and monkeys, I have made observations on the effect on respiration of section of the brain stem at different levels. In this paper I give an account of the effect of such section in the cat. The observations of earlier observers have been made chiefly on the rabbit, and it will be seen that the results in the cat differ in some important points from those obtained by others in the rabbit.

Ribosomal protein (rp)S5 belongs to the family of the highly conserved rp’s that contains rpS7 from prokaryotes and rpS5 from eukaryotes. Alignment of rpS5/rpS7 from metazoans (Homo sapiens), fungi (Saccharomyces cerevisiae) and bacteria (Escherichia coli) shows that the proteins contain a conserved central/C-terminal core region and possess variable N-terminal regions. Yeast rpS5 is 69 amino acids (aa) longer than the E. coli rpS7 protein; and human rpS5 is 48 aa longer than the rpS7, respectively. To investigate the function of the yeast rpS5 and in particular the role of its N-terminal region, we obtained and characterized yeast strains in which the wild-type yeast rpS5 was replaced by its truncated variants, lacking 13, 24, 30 and 46 N-terminal amino acids, respectively. All mutant yeast strains were viable and displayed only moderately reduced growth rates, with the exception of the strain lacking 46 N-terminal amino acids, which had a doubling time of about 3 h. Biochemical analysis of the mutant yeast strains suggests that the N-terminal part of the eukaryotic and, in particular, yeast rpS5 may impact the ability of 40S subunits to function properly in translation and affect the efficiency of initiation, specifically the recruitment of initiation factors eIF3 and eIF2.

IN two previous articles(1), four respiratory centres were located, namely, the gasping centre at the nceud vital, Fig. 1 (5-6), the expiratory centre just above this, Fig. 1 (4-5), the apneustic centre which gives rise to inspiratory tonus (apneusis) and is placed at the level of the striv acousticse, Fig. 1 (34), and the pneumotaxic centre in the upper half of the pons, Fig. 1 (1-2), which produces respiration of normal type by periodically inhibiting apneusis. The present paper deals with the chemical, and afferent nervous, influences which regulate the activity of centres 1, 2 and 3. Gasping. The influences affecting gasping may best be studied after all the higher centres have died, or have been eliminated by section of the brain stem at level 5, Fig. 1.

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