Macro- and microbehavioral response to viscosity among rats licking saccharin

Abstract

Effects of viscosity upon licking were studied by providing rats with thick and thin .4% saccharin solutions in separate 1-h sessions. Volumetric intake{lick was greater for the thin than for the thick solution and was the only measure affected by viscosity. As the session progressed, the two solutions caused (1) comparable satiation effects, as evidenced by comparable decreases in several indices of the average rate of ingestion; (2) comparable decreases in the average duration of the lick; and (3) no reliable change in the average volumetric intake of the lick. The results were related to earlier comparisons of liquid food and saccharin and indicated that the differences produced by the latter solutions are not fully attributable to their differential viscosity.

Functional Anatomy of the Tongue and Mouth of Mammals

“…A similar decrease occurs in hamsters (Schaeffer and Huff, 1965) and several other mam mals (Cone, 1974 (Snyder and Hulse, 1961;Davis, 1973;Schaeffer and Premack, 1961;Halpern, 1975 (Keehn and Arnold, 1960;Snyder and Hulse, 1961;Schaeffer and Premack, 1961), viscous and nonviscous saccharin (WiIcove and Allison, 1972), NaCI (Halpern, 1975), cellulose suspended in water (Halpern, 1975), and sucrose (Davis, 1973; B. P. Halpern and T. L. Nichols, unpublished observations). With continued licking, a decline in licking rate results both from highly restricted access, in which only the tip of the tongue contacts the drinking tube during a lick (Snyder and Hulse, 1961;Halpern, 1975) Halpern and T. L. Nichols, unpublished observations).…”

CONTRAST, INDUCTION, FACILITATION, SUPPRESSION, AND CONSERVATION1

“…Equations 12 and 13 show that as k approaches zero, NI will remain highly sensitive to variations in I, but NC will approach complete insensitivity to variations in I. More generally, as k approaches zero the total amount of Response c will approach the baseline amount, O,, independently of the schedule parameters I and C. If the dimension were energy expenditure, k might be made to approach zero by lightening the lever, by making the fluid in the spout more viscous (Wilcove and Allison, 1972), or the aperture of the spout more narrow.…”

Distinct competitive impacts of palatability of taste stimuli on sampling dynamics during a preference test.

“…However, in our task, the anticipated taste delivery corresponds to the actual taste delivery (after the very first sample), so anticipated palatability corresponds to the actual palatability. Moreover, in experiments of our ilk, in which the stimulus at a lick spout is always present, the total amount of liquid consumed (the standard measure of palatability) is directly proportional to the number of licks (Dwyer et al, 2008; Lin et al, 2012; Wilcove & Allison, 1972).…”

“…Palatability is typically evaluated through measurement of the amount of a food or solution consumed. Given that the mean amount consumed per lick has been shown to be very stable across time (Wilcove & Allison, 1972), in this study we consider the total number of licks of a solution as a reasonable quantification of palatability. But since rats sample a solution in clearly demarcated bouts with high frequency (approximately 6 Hz) regular sampling within a bout, we have gone beyond this simple measurement, making use of two dynamic factors that have been shown to provide "real-time" measures of palatability: the duration of the bouts and the total number of bouts.…”