Abstracts of the British Society of Audiology Short Papers Meeting on Experimental Studies of Hearing and Deafness

International Journal of Audiology 2010; 49: 141–183 Abstracts of the British Society of Audiology Short Papers Meeting on Experimental Studies of Hearing and Deafnesss of the British Society of Audiology Short Papers Meeting on Experimental Studies of Hearing and Deafness September 18–19, 2008, Department of Psychology, University of York, UK Poster communications Characterization of fi brocyte cultures from rat and mouse spiral ligament S. Mahendrasingam, P. Robinson and D.N. Furness. Institute for Science and Technology in Medicine, Keele University, Keele, UK Five main types of fi brocyte are distinguishable in the spiral ligament by their morphology, location, and relative expression of specifi c proteins: types III and IV fi brocyte express caldesmon, type I expresses also S-100, whilst types II and V express both plus Na+/K+ATPase and the glutamate transporter GLAST. Fibrocyte cultures may be useful in the development of cellular transplantation therapy to ameliorate strial presbyacusis, and have previously been grown from gerbils and mice. The aim of this study was to characterize fi brocyte cultures grown from adult Sprague-Dawley rats, CD-1 and CBA/CaJ mice. Methods were based on those of Suko et al (2000). Cochleae were excised and opened in culture medium (Invitrogen, MEM-α). Lateral wall segments were placed strial side down in collagen I coated 30 mm wells, cover-slipped and left overnight, after which the coverslip was removed. Adherent segments were incubated for 2–3 weeks, forming primary cultures, trypsinized and reseeded for secondary culturing. For immunostaining, secondary cultures grown for 2–3 weeks on coverslips were fi xed in paraformaldehyde and labelled for caldesmon, S-100, Na+/K+ATPase, or GLAST. For scanning electron microscopy coverslips were fi xed in glutaraldehyde and osmium tetroxide, dried and coated with gold. For transmission electron microscopy cells were grown on plastic sheets, fi xed in glutaraldehyde and osmium tetroxide and embedded in Spurr resin. Sprague-Dawley rat and CD-1 mice cultures grew well and were sub-cultured easily. Cultured cells varied in morphology, either long and/or broad with thin processes, spindle-like or small stellatelike shapes. CBA/CaJ cultures developed poorly, giving rise to squamous and spindle-like cells, and were not characterized further. Rat and CD-1 cultured cells showed positive caldesmon labelling resembling stress fi bre patterns of fi broblasts. Broader cells were weakly positive for Na+/K+ATPase around the nucleus, and S-100 and GLAST, spread throughout the cells. The spindle and stellate cells were strongly positive for all three. Preliminary analysis of CD-1 cultures using transmission electron microscopy showed the highly fl attened broad cells to contain normal mitochondria and actin stress fi bres. These results show that cells that express proteins characteristic of all the fi brocytes can be grown from the lateral wall of both rats ISSN 1499-2027 print/ISSN 1708-8186 online DOI: 10.3109/14992020903426264 „ 2010 British Society of Audiology, International Society of Audiology, and Nordic Audiological Society Received: October 16 2009 Accepted: October 16 2009 and mice. However, some mouse strains may be more suitable than others. Culture cells from CD-1 adults may be in better condition metabolically than their precursors as they have normal mitochondria unlike those found in situ in three to fi ve-week old mice.