Morphology of substance P immunoreactive neurons in human cortex of the inferior parietal lobule

Abstract

Objective. This study was conducted in order to find out whether there was any particular association between the neuronal body shapes and their immunoreactivity on substance P neurons in the supramarginal and angular gyri of inferior parietal lobule (IPL). Methods. Substance P (SP) neuropeptide was examined in the human brain (3 male and 4 female) without any neurological and psychiatric diseases, by using the method of immunohistochemistry. Immunoreactive neurons and fibers were visualized by using Olympus BT2 Camera Lucida. The collected data were statistically analyzed by using one-way analysis of variance, with the probability level p=<0.05. Results. The largest somas were obtained among SP positive neurons. Average diameters (± SD) were: longer diameter 44.93 ± 15.69 μm, shorter diameter 18.16 ± 3.77 μm. One-way analysis of variance revealed the highly significant difference among the longer axis of immunopositive neurons (p=0.002). Conclusion. A quarter of detected SP neurons were localized in lamina II of the IPL cortex. The least populated layer was lamina I (less than a tenth of all immunoreactive neurons).