Nerve cell rearrangement in neocortical layers of MAM treated foetal mice.
In this study we examined the changes in cortical layers when Methylazoxymethanol-acetate (MAM) was injected on 13th, 15th and 17th day of gestation (MAM13, MAM15, MAM17). Prenatal MAM administration prevents neuron precursor proliferation; the subsequent cell number decrease is followed by an increase in size of surviving cells. When MAM was injected on 13th or 15th day of gestation the significant decrease in cell density, in II and III zone (MAM13) and in the upper layers (MAM15), was compensated by a proportional increase in cell size and synaptic density. When MAM was injected on 17th embryonal day it did not cause a significant change in the neuron density and soma size was not altered while the distribution of cell size among layers showed significant differences with respect to the controls. Our findings of some area and synaptic density show that the cell surface increase is proportional to the decrease in cell number and that in the surviving cells there is a rearrangement in synaptic connections that compensate for the cellular density decrease.
Ciaroni
S
S
Istituto Scienze Morfologiche Università-Urbino.
Cecchini
T
T
Ambrogini
P
P
Minelli
G
G
Del Grande
P
P
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002540:Cerebral Cortex / Q000166:cytology / Q000187:drug effects* / Q000196:embryology; D005260:Female; D005333:Fetus / Q000187:drug effects*; D005865:Gestational Age; D008431:Maternal-Fetal Exchange; D008746:Methylazoxymethanol Acetate / Q000008:administration & dosage / Q000494:pharmacology*; D051379:Mice; D008854:Microscopy, Electron; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D011247:Pregnancy; D012016:Reference Values; D013569:Synapses / Q000187:drug effects* / Q000648:ultrastructure
D008746:Methylazoxymethanol Acetate