Anatomical Variations of the Temporomesial Structures in Normal Adult Brain - A Cadaveric Study.

BACKGROUND: Despite significant evolutional, functional, and clinical interest, the anatomical variations of the temporomesial structures in cadaveric samples have received little attention. This study was undertaken to document the anatomical variations observed in the temporal lobe of human brain with emphasis on the structures present in temporomesial region. MATERIALS AND METHODS: Using 26 postmortem cadaveric cerebral hemispheres (13 right and 13 left hemispheres), several neurosurgically significant mesial structures were studied by blunt dissection under the operating microscope. The observed surface-based qualitative variations and right-left asymmetries were tabulated under well-defined, moderately defined, and ill-defined classification. RESULTS: Among the areas, uncus (100%), limen insulae (88.4%), rhinal sulcus and hippocampus (81%), intralimbic gyrus (77%), Heschl's gyrus (73%), gyrus ambiens, semilunar gyrus, sulcus semiannularis, and calcar avis (69.2%) were well defined, and band of Giacomini (38.4%) was found to be distinctly ill-defined areas in the list. Further, our analysis confirmed the presence of consistent left-greater-than-right asymmetry in all the areas of interest in temporal region under well-defined category. Rightward asymmetry was noticed in moderately defined and ill-defined classification. However, no asymmetry was detected in the uncal region. P value for all the obtained results was >0.05. CONCLUSION: Our study offers a preliminary anatomic foundation toward the better understanding of temporal lobe structures. These variations may prove valuable to neurosurgeons when designing the appropriate and least traumatic surgical approaches in operating the temporomesial lesions.

Histomorphometric study of basilar artery in normal and suicide persons.

BACKGROUND: Depression in association with cerebro-vascular risk factors and white matter lesions is increasingly referred to as 'vascular depression'. There are several brain areas known for playing a role in patho-physiology of depression which may lead to suicidal tendencies, are fed by basilar artery. Therefore, the arterial histoarchitecture was studied in the normal and suicide individuals to establish a relationship between the vascular structural changes and depression. METHODS: 40 post-mortem samples (both sexes) of basilar artery have been collected and were grouped into normal and suicide groups. Samples were measured for arterial, lumen diameter and the thickness of tunica intima, media and adventitia using H & E stained sections. While, Orcein stained sections were used to estimate the volume fraction of elastic fibres, and Van Gieson stained sections to estimate the volume fraction of collagen fibres. RESULTS: The mean thickness of tunica media of basilar artery in suicide individuals (1.08 microns) showed a statistically significant decrease when compared to normal person (1.33 microns). Further, volume fraction of collagen (0.06 mm3/mm3) and elastic fibres (0.06 mm3/mm3) in suicide persons showed a statistically significant decrease when compared to normal person (collagen fibres 0.08 mm3/mm3; elastic fibres 0.09 mm3/mm3). CONCLUSIONS: This study establishes a probable causative relationship between vascular structural abnormality and depression which may drive the individual to commit suicide.

Aging causes morphological alterations in astrocytes and microglia in human substantia nigra pars compacta.

Age being a risk factor for Parkinson's disease, assessment of age-related changes in the human substantia nigra may elucidate its pathogenesis. Increase in Marinesco bodies, α-synuclein, free radicals and so forth in the aging nigral neurons are clear indicators of neurodegeneration. Here, we report the glial responses in aging human nigra. The glial numbers were determined on Nissl-stained sections. The expression of glial fibrillary acidic protein, S100ß, 2', 3'-cyclic nucleotide 3' phosphodiesterase, and Iba1 was assessed on cryosections of autopsied midbrains by immunohistochemistry and densitometry. The glial counts showed a biphasic increase, of which, the first prominent phase from fetal age to birth could be physiological gliogenesis whereas the second one after middle age may reflect mild age-related gliosis. Astrocytic morphology was altered, but glial fibrillary acidic protein expression increased only mildly. Presence of type-4 microglia suggests possibility of neuroinflammation. Mild reduction in 2', 3'-cyclic nucleotide 3' phosphodiesterase-labeled area denotes subtle demyelination. Stable age-related S100ß expression indicates absence of calcium overload. Against the expected prominent gliosis, subtle age-related morphological alterations in human nigral glia attribute them a participatory role in aging.