|
|
Research Interests: Neurophysiology
Using classical electrophysiological recordings and molecular biological techniques to study the functional properties of the Merkel cell - neurite complexes (MCN) in mammalian skin. MCN is the slowly adapting type I cutaneous mechanoreceptors located at the epidermal dermal border in hairy, glabrous skin as well as in the hair follicles.
Since 1950s physiologists and anatomists have started to study the MCN but due to its unique location in the skin, the exact cellular signal transduction mechanism of how mechanical force is transform to electrical signal, which can then be conveyed to the central nervous system, is still under debate. There is a lot of evidence suggesting the presence of different types of neurotransmitters from immunohistochemical studies but there are findings that the MCN involves no neurotransmitter. In the sinus hair follicles the MCN are found to be confined in the area surrounded the mid sinus region. They can also be made fluorescent by loading with quinacrine.
The present project is to find out what are the candidates of neurotransmitters in the MCN and their involvement in the signal transduction. By extracting the total RNA from the tissue that is fluorescent (i.e. MCN) after quinacrine loading followed by RT-PCR to obtain the cDNA, different primers for known and related candidates (e.g. serotonin, VIP, CGRP, pro-enkephalin, etc..) are prepared. After the PCR and DNA sequencing, the possible peptide candidates for the neurotransmitters can be found. Quantitative PCR techniques is being developed to quantitate the PCR products and hopefully to find out the neurotransmitter in MCN.
Selected Publications:
*Leung,M.S. Dynamic and static responsiveness of SAI receptors in hypothyroid rats. In L.M.Pubols & B.J.Sessle (eds.): Effects of injury on trigeminal & spinal somatosensory system. pp.483, Alan R. Liss, New York. (1987)*Baumann,K.I., W.Hamann & M.S.Leung. Acute effects of neomycin on slowly adapting type I and type II cutaneous mechanoreceptors in the anaesthetized cat and rat. J. Physiol. 425:527-544 (1990)
*Leung,M.S. & C.C.Wong. Effects of testosterone on G-proteins in regenerating rat sciatic nerve. Can. J. Physiol. Pharmacol. 72 (Suppl. 1):546 (1994)
*Leung,M.S., C.C.Lau & C.C.Wong. Effects of neonatal 5,7-dihydroxytryptamine and 6-hydroxydopamine treatment on the alpha subunits of G-proteins, Gs and Go in the cerebral cortex of the rat. Neurosc. Lett. Suppl. 47:S16 (1997)
[ HOME ]
