Neuronal membrane remodelling during the oestrus cycle: a freeze-fracture study in the arcuate nucleus of the rat hypothalamus.
Freeze-fracture methodology was used to study the organization of the neuronal plasma membrane in the rat arcuate nucleus, an oestrogen sensitive area of the hypothalamus. The quantitative evaluation of freeze-fracture replicas of the perikarya, dendritic shafts and dendritic spines revealed that the numerical density of intramembranous particles varied during the ovarian cycle. The number of small (less than 10 nm) particles was decreased, and the number of large (greater than 10 nm) particles was increased, in the P-face of the perikaryal plasma membranes in prooestrus and oestrus when compared to dioestrus. This change was associated with a significant increase in the number of exo-endocytotic images in the perikaryal plasma membrane in prooestrus. Changes in intramembranous particles during the ovarian cycle were not detected in arcuate nucleus dendritic shafts and dendritic spines.
Garcia-Segura
L M
LM
Instituto Cajal, C.S.I.C., Madrid, Spain.
Hernandez
P
P
Olmos
G
G
Tranque
P A
PA
Naftolin
F
F
D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000648:ultrastructure*; D002462:Cell Membrane / Q000648:ultrastructure; D003712:Dendrites / Q000648:ultrastructure; D004971:Estrus / Q000502:physiology*; D005260:Female; D005614:Freeze Fracturing; D009474:Neurons / Q000648:ultrastructure*; D051381:Rats; D011919:Rats, Inbred Strains