Abstract
Parallel morphological and electrophysiological studies of embryonic neocortical tissue (primordia of anterior parietal–presumptive sensorimotor–cortex) grafted into different regions of the host adult brain (sensori-motor cortex, caudate-putamen, septum or thalamus) were carried out to investigate to what extent the properties of transplanted embryonic neocortex–an advanced organizational form of neuronal tissue–are affected by homotopic or heterotopic surroundings.The results point to the importance of the host tissue environment as it influences both the size, the morphological and functional properties of the implanted embryonic cortical plate tissue. The cortical grafts were smaller in size when developed homo-topically in sensorimotor cortex and grew larger in heterotopic environment (caudate-putamen, septum, thalamus). The orientation of neuronal dendrites in the grafts tends to follow that seen in the surroundings. The homotopic grafts showed a better structural integration into the host brain. Differences were seen between intracortical and subcortical transplants in the spontaneous firing rate of neurons and in the ratio of units with various types of spontaneous discharge.
Highlights
It is well established that during the process of brain development cellular elements mutually influence each other and such reciprocal "environmental" effects exist in almost all steps of maturation
The cortical grafts were smaller in size when developed homo-topically in sensorimotor cortex and grew larger in heterotopic environment
In order to get a better insight into this question, neuronal grafting techniques have recently been frequently employed with the objective of investigating whether fetal CNS tissue implants, transplanted into different areas of the adult host brain, develop those organizational features which generally resemble the structures seen in situ
Summary
It is well established that during the process of brain development cellular elements mutually influence each other and such reciprocal "environmental" effects exist in almost all steps of maturation. In order to get a better insight into this question, neuronal grafting techniques have recently been frequently employed with the objective of investigating whether fetal CNS tissue implants, transplanted into different areas of the adult host brain, develop those organizational features which generally resemble the structures seen in situ. Data from literature show that the transplanted precursor cells complete their predetermined program of histogenesis regardless of any discrepancy between the place of origin of the transplant and the site in the host brain, and all the cellular forms typical of the original structure may develop in the transplant/1,3-5, 18,22,31,34/. Indicate that the degree of organizational features of the anatomically integrated graft tissue varies depending on the developmental stage, the place of origin and the site of the implantation of the host brain/9,11-13,19,20,24,28, 29,33/
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
