Journal of Neuroscience, Vol 7, 2697-2702, Copyright © 1987 by Society for Neuroscience
Medial preoptic sexual dimorphisms in the guinea pig. II. An investigation of medial preoptic neurogenesis
W Byne, JT Warren and I Siggelkow
Neurogenesis was studied in the medial preoptic area of the guinea pig by
the method of tritiated thymidine autoradiography. Eight cytoarchitectonic
divisions were examined, 4 of which display sexual dimorphism and 4 that do
not. Neurogenesis in the nonsexually dimorphic divisions was found to end
at embryonic day (E) 27, while in each of the sexually dimorphic divisions
neurogenesis continued after this and persisted until at least E31 in the
central compact and principal portions of the medial preoptic nucleus.
Since the testes become active at E25 in the guinea pig (Resko, 1970), it
is possible that gonadal secretions influence the proliferation and
subsequent developmental processes of neurons destined for the sexually
dimorphic nuclei.