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A Lakshminarasimhan

Publications and source records attributed to A Lakshminarasimhan.

10 recordsLinked to original sources
PubMed1982

The morphology and cytoarchitecture of the red nucleus of the one-humped camel (Camelus dromedarius).

The red nucleus of the camel was delineated and reconstructed. For this purpose, three camel brain stems were used for making serial sections in the transverse, sagittal and horizontal planes after double embedding in celloidin-paraffin. All sections were mounted. Nissl and nissl-myelin methods were used for staining. The red nucleus was reconstructed by using a Leitz drawing device; it was seen to have the shape and form of an egg with a flattened medial surface. The red nucleus measures 8.35 mm (length) X 5.00 mm (width) X 3.70 mm (height) and extends from just caudal to the oculomotor nerve fibres to the fasciculus retroflexus rostrally. Five cell types were seen namely, giant, large, medium, small and minimus. The red nucleus shows a larger rostral parvocellular and a smaller caudal magnocellular divisions. The parvocellular division shows three subdivisions namely, the pars veniralis, pars dorsomedialis and cornu lateralis. The red nucleus and its giant cells are the largest reported in literature so far; the giant cells are quite similar to the large ventral spinal motor neurons. The camel cerebellum is very big and this fact along with the greatly developed red nucleus and rubrospinal tract may account for the great muscular control and coordination necessary for the camel to survive in the peculiar desert environment, it is exposed to.

Animals↗
PubMed1975

The isocortex of the ox (Bos taurus). I. The sulci and gyri.

A simplified scheme of the functionally important gyri and the sulci delimiting these areas, in the ox, is presented. The criteria used are the cyto- and myelo-architecture of the different areas and their correlation with the available physiological information of the nearest ungulates. The preparation of the brain map and experimental studies to determine the thalamocortical connections and later electrophysiological studies are thus possible. The following conclusions have been drawn: 1. The coronoansate sulci are the equivalents of the central sulcus of man. 2. The cruciate sulcus delimits the motor cortex caudally. 3. The equivalent of the calcarine sulcus of man, is the caudal part of the intralimbic sulcus, the axial sulcus of the striate area. 4. The suprasylvian sulcus forms the equivalent of the parietooccipital fissure of man. 5. The equivalent gyri of the isocortical areas of man are defined and the mechanical processes involved in the deformation pattern of the sagittaly oriented gyri of the subprimate mammals resulting in the coronal gyral pattern of man, are described.

Animals↗
PubMed1975

The isocortex of the ox (Bos taurus). II. The cortical types, serial sections and brain map.

1. The cerebral hemispheres of the bovine brain have been studied by making serial sections in the different planes and employing Nissl, myelin and silver (protargol) methods. 2. Ten different cortical (architectural) types have been determined. 3. The somatomotor (Ms I, Ms II), somatosensory (Sm I, Sm II), auditory and visual areas of the cerebral cortex have been delimited. 4. A brain map with a symbolic scheme, has been prepared, based on the cyto- and myeloarchitectural findings and comparative experimental work on the nearest ungulates, other subprimates and primates including man. 5. The importance of the general eulaminate cortex, and its abundance in the frontal, temporal, and parietal lobes of man, which distinguish the human from the other brains are indicated. 6. It is concluded that the preparation of a brain map for this species, is the first step towards future experimental, neurophysiological and related fields of work.

Animals↗