The age-dependent change in olfactory periglomerular neuronal populations is not affected by interrupting subventricular neuroblast migration in adult rats.
The olfactory bulb (OB) is rich in the number and variety of neurotransmitter and neuropeptide containing cells, in particular in the glomerular layer. Several reports suggest that numbers of some periglomerular phenotypes could change depending on age. However, it is unclear whether the different classes of periglomerular interneurons are modified or are maintained stable throughout life. Thus, our first objective was to obtain the absolute number of cells belonging to the different periglomerular phenotypes at adulthood. On the other hand, the olfactory bulb is continously supplied with newly generated periglomerular neurons produced by stem cells located in the subventricular zone (SVZ) and rostral migratory stream. Previously, we demonstrated that the implantation of a physical barrier completely prevents SVZ neuroblast migration towards the OB. Then, another objective of this study was to evaluate whether stopping the continuous supply of SVZ neuroblasts modified the different periglomerular populations throughout time. In summary, we estimated the total number of TH-IR, CalB-IR, CalR-IR and GAD-IR cells in the OB glomerular layer at several time points in control and barrier implanted adult rats. In addition, we estimated the volume of glomerular, granular and complete OB. Our main finding was that the number of the four main periglomerular populations is age-dependent, even after impairment of subventricular neuroblast migration. Furthermore, we established that these changes do not correlate with changes in the volume of glomerular layer.
Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas and Grupo de Investigación en Células Troncales IMPULSA 02, Universidad Nacional Autónoma de México, 04510 México, DF, Mexico.
Jatziri I
JI
Contreras-García
Leticia
L
Rodríguez-Castañeda
Gisela
G
Gómez-Lira
Rogelio
R
Ramírez-Hernández
Horacio
H
Villafán
Leticia
L
Granados-Rojas
Gabriel
G
Gutiérrez-Ospina
Julieta G
JG
Mendoza Torreblanca
D000367:Age Factors; D000818:Animals; D064032:Calbindin 2; D064026:Calbindins; D002452:Cell Count; D002455:Cell Division; D002465:Cell Movement; D002552:Cerebral Ventricles; D018698:Glutamic Acid / Q000378:metabolism; D007150:Immunohistochemistry; D007395:Interneurons / Q000166:cytology* / Q000502:physiology; D008297:Male; D009830:Olfactory Bulb / Q000166:cytology* / Q000254:growth & development; D051381:Rats; D017208:Rats, Wistar; D064030:S100 Calcium Binding Protein G / Q000378:metabolism; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
D064032:Calbindin 2; D064026:Calbindins; D064030:S100 Calcium Binding Protein G; D018698:Glutamic Acid; D014446:Tyrosine 3-Monooxygenase