Distribution of amiloride-sensitive sodium channels in the oral cavity of the hamster

The distribution of amiloride-sensitive sodium channels (ASSCs) in taste buds isolated from the oral cavity of hamsters was assessed by patch clamp recording. In contrast to the case for rats, taste cells from the fungiform, foliate and vallate papillae and from the soft palate all contain functional ASSCs. The differential distribution of ASSCs between the hamster and the rat may be important for understanding the physiology underlying the differing behavioral responses of these species to sodium salts.      

In-situ characterization of the uncrimping process of arterial collagen fibers using two-photon confocal microscopy and digital image correlation

Uncrimping of collagen fibers in the arterial wall is an integral process in regulating the macro-level mechanical response of arteries. Uncrimping of collagen fibers leads to a gradual, but significant strain-stiffening response of the artery at physiological pressures and prevents overdistention at elevated pressures. In this study, we imaged adventitial collagen fibers from fresh primate arteries using two-photon excitation microscopy while subjecting the arteries to physiological inflation pressures and axial stretches. The imaging focal plane was fixed at a constant radial location in the adventitial wall by adjusting the focal distance as the arteries inflated, allowing for the continuously monitoring of the uncrimping process of a single region of collagen fibers. Digital image correlation was then applied to the sequential images to assess and correlate the local displacements to manual traces of selected reference fibers and their engagements. We found that the collagen fibers of interest became fully engaged at a luminal pressure of 20 mmHg, this was then followed by rotation of these fibers as the bulk artery continued to dilate. This technique helps to further the understanding of the uncrimping process of collagen fibers under physiological loads, which can aid in the development of more accurate microstructural constitutive models.