International Journal of Basic and Applied Medical Sciences ISSN: 2277-2103 (Online) An Online International Journal Available at http://www.cibtech.org/jms.htm 2012 Vol. 2 (1) January-April, pp.52-55/Bhimadevi et al. Research Article 52 HISTOMORPHOGENESIS OF FULLTERM FOETAL NUCLEUS PROPRIUS OF SPINAL CORD *Bhimaidevi N, Narasingarao B, Sunitha V, Pramila Padmini Department of Anatomy, Maharajah’s Institute of Medical Sciences, Nellimarla – 535 217 ABSTRACT The centre for perception of all sensory modalities is the dorsal horn of the grey matter of spinal cord. In mammals including man six laminae were designated by Rexed. The literature available on cytoarchitecture nucleus proprius of the dorsal horn of spinal cord is restricted to mammals other than man. The present study is an attempt to observe histomorphometry of neurons of nucleus proprius of cervical segment of spinal cord, numerical density and population study of nucleus proprius. The spinal cord of a destitute full term foetus has been dissected and processed for light microscopic study. Holme’s silver nitrate staining was done for all sections. Nucleus proprius was found to be bulbous. There is a difference between right and left nucleus proprius in as far as morphometry, numerical density and population study. Key Words: Nucleus Proprius, Substantia Gelantinosa Rolando, Quantitative Study, Morphometric Study And Population Study INTRODUCTION The cell dynamic of dorsal horn of grey matter is to be understood by the quantitative and the population studies. The morphometric analysis of nucleus proprius of cervical segment of human spinal cord at the full term is being undertaken in the present study. The study involved the measurement of cell dimensions by applying stereological principle to microanatomy (Meyhew, 1983). Abercrombie (1946) applied these principles to understand morphometric study and revolutionize this field. Histomorphometry of nucleus proprius in rat lumbar spinal cord was studied by Bharadwaj et al., (2001) is available. However the cytoarchitecture of human foetal dorsal horn of spinal cord has not been traced in the literature. The cytoarchitecture of dorsal horn in macaque (Ralston, 1979), in cat (Ralston, 1982) and also in pigeon (Leonard, 1975) is available.An attempt is made to study the cytoarchitecture of nucleus proprius of human foetal spinal card with reference to histomorphometry, numerical density and population study. MATERIALS AND METHODS One full term destitute male foetus available in the department of anatomy MIMS medical collage is the study material. The foetus has been perfused with 10% formalin has per the protocol. After 72 hours laminectomy was done and the spinal cord was exposed. Cervical segment was identified and 1mm thick cervical spinal cord segment was processed for light microscopic study. Five microns thick sections were taken and stained with H and E, and Holme’s silver nitrate stain for identification of the tract cells of nucleus proprius. Morphometric studies as well as population studies have been done. The nucleus proprius constituted rounded and spindle shaped neurons. After going through all the sections, the length and breadth of nucleus proprius was calculated by using stage and eye piece micrometer. The volume was calculated by ab 2 π/6 of the physics formula. The formula advocated by Salim and Krishna Murthy i.e. number of cells per cubic mm X total volume of the nucleus = total number of cells in the nucleus proprius was used. RESULTS The nucleus proprius is identified as bulbous expansion of dorsal horn of spinal cord of cervical segment (Fig 1).