Department that Anatomy, research study Institute of clinical Science, Konkuk University institution of Medicine, Seoul, Republic the Korea
Prof. Dr. Med. Wu-Chul Song

Department the Anatomy, Konkuk University school of Medicine

1 Hwayang-dong, Gwangjin-gu

Seoul 143-701 (Republic of Korea)

Tel. +82 2 2030 7819, E-Mail anatomy

Abstract

The vibrissal capsular muscle (VCM) that the rat is recognized to different from the arrector pili muscle. The objective of the present study was to characterize the rat VCM morphologically making use of three-dimensional reconstruction. The rat snout skin to be fixed, handle with regime histological methods, sectioned serially in ~ a thickness the 10 µm, and then stained v Masson’s trichrome. The sectioned photos were rebuilded three-dimensionally using ‘Reconstruct’ software. The findings confirmed that the VCM is a skeletal muscle attached come the vibrissal follicle such the the last is rooted within the former. The VCM encircles the follicle nearly entirely, from basic to apex, and also hooks roughly the follicle caudally. Each one of these capsular muscles is associated to two nearby follicles in the very same row. They overlap each various other in the reduced part, as the rostral follicular muscle the surrounds the caudal follicle. The present findings suggest that the vibrissae room able to move an ext freely (under spontaneous control) than other general arrector chili muscles, in line v their sensory function.

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Introduction

It is known that the morphology and also origin differ between the vibrissal capsular muscle (VCM) and the arrector pili muscle. The arrector chili muscle of body hair is smooth muscle and also is associated from the dermal papillary layer come the hair follicle. In the rat, the VCM is a blended muscle developed by fibers from the nasolabialis and also maxillolabialis muscles . Lock are associated with vibrissal follicles and are just partially placed into the upper dermis and epidermis. The VCM develops a hook or sling the connects with various other vibrissae, and is situated in the adipose tissue, allowing the complimentary movement of the follicle . The activity of the vibrissae is managed by the facial engine nerve .

The examine by Haidarliu et al. <2010> gave very detailed information about the muscle design in the rat vibrissa. However, this study concentrated mainly top top the extrinsic muscle. The current study focused on the morphological aspect of the intrinsic muscle, i.e. The VCM. The two-dimensional schematic drawings derived in vault studies have not revealed a definitive place or circulation of the VCM.

Cross-sectional research studies were presented to be the best an approach of investigating hair follicles , v three-dimensional (3-D) reconstruction based on serial cross sections, which disclose the actual microstructure and role of hair follicles and also their appendages . Moreover, ours previous 3-D restoration study proved that the framework of the vibrissal follicle-sinus facility differed from previous reports . The function of the present study was to determine the rat VCM morphologically using 3-D reconstruction. The functional aspects of the VCM were then reevaluated based upon morphology.

Materials and Methods

Materials and also Sampling

Sprague-Dawley rats at 10–12 main of age were used. The pets were perfused with 150 ml of saline complied with by 600 ml of fixative containing 4% paraformaldehyde in phosphate-buffered saline. The skin that the lateral region, the harvested region, to be C2–C5 and D2–D5 of the vibrissal plan of the rat , including the vibrissal follicle-sinus complexes. The samples were postfixed with 10% neutral-buffered formalin. The specimens were trimmed to 15 × 10 mm to do them easier to handle and to facilitate the acquisition of images throughout fixation.

Tissue Processing

After dehydration and paraffin infiltration, every sample was embedded epidermis side down. The paraffin-embedded specimens were cut transversely and also serially from the surface of the epidermis down to the lower dermis – to incorporate the full length of the follicles – in ~ a thickness that 10 µm, and used because that 3-D reconstruction. The number of sections varied with the size of the follicles, however ranged native 300 come 400. The serially sectioned tissues to be stained v Masson trichrome.

3-D Reconstruction

All the the stained sections to be photographed using a 2,048 × 1,536 pixel digital CCD camera (DP70; Olympus, Tokyo, Japan). 3 or 4 vibrissal follicle-sinus complexes were reconstructed from each specimen. ‘Reconstruct’ software was offered to produce the 3-D photos of the VCM and also the vibrissal follicle (this software program was downloaded from http://synapses.clm.utexas.edu/tools/reconstruct/reconstruct.stm) . The images were set manually making use of the software. The frameworks were aligned along the exterior margin and also then reconstructed.

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Results

The VCM surrounding the vibrissal follicle from base to apex was grouped v a rostral follicle and also neighbored a caudal follicle in the exact same row (fig. 1, 2). A single muscle to be hook-shaped, encircling the superior region of the caudal follicle and also the inferior an ar of the rostral follicle (fig. 2). The top muscle fiber of the VCM (ring sinus level) to be C-shaped and also kept a chop grip ~ above the superior rostral surface ar of the follicle, with the exception of the premium caudal part of the follicle (fig. 1). The reduced fiber the the VCM (cavernous sinus level) to be sling-shaped and attached to both the rostral and also caudal follicles (fig. 2b, c). Individual muscle overlapped each various other so that the caudal part of the rostral VCM wrapped partially around the rostral component of the caudal VCM (fig. 2, 3). The direction that the muscle fiber was roughly parallel come the skin surface ar at the rostral surface ar of the lower component of the VCM, when it to be oblique in the middle parts and also vertical in the upper component of the VCM (fig. 3).