Quantifying presynaptic terminals at the light microscope level in intact and deafferented central nervous structures.
Quantification of presynaptic terminals often requires laborious techniques that involve tissue preparation for ultrastructural analysis. Modern preembedding immunohistochemical techniques provide a high morphological resolution at the light microscope level, thus allowing us to identify immunostained presynaptic boutons using specific antibodies. When absolute density of boutons (D(a)) is analysed for comparison between control and deafferented nervous tissue, quantification may be distorted due to tissue shrinkage that follows deafferentiation. The magnitude of this effect must be, therefore, estimated to correct quantitative data. Using the superior colliculus (SC) as a model, an easily applicable protocol to quantify the density of small size labelled particles in control and deafferented nervous tissue is described. This protocol was used to analyse the effect of neonatal and adult enucleation on the adult pattern of cholinergic input to the rat SC. Statistical treatment of data demonstrated that neonatal enucleation caused a drastic increase in bouton density in the visual collicular layers, stratum zonale (SZ) and stratum griseum superficiale (SGS). The same lesion carried out in adult animals caused an increase in the bouton density exclusively in the SZ.
Department of Neurosciences, Faculty of Medicine, University of the Basque Country, 48940 Leioa, Bizkaia, Spain.
Inmaculada
I
Gerrikagoitia
Gontzal
G
García del Caño
Luis
L
Martínez-Millán
D000375:Aging / Q000378:metabolism; D000818:Animals; D002452:Cell Count / Q000379:methods*; D002799:Cholinergic Fibers / Q000473:pathology* / Q000648:ultrastructure; D003714:Denervation; D015353:Eye Enucleation; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation / Q000379:methods; D007150:Immunohistochemistry / Q000379:methods*; D008297:Male; D009473:Neuronal Plasticity / Q000502:physiology; D017729:Presynaptic Terminals / Q000473:pathology* / Q000648:ultrastructure; D051381:Rats; D017207:Rats, Sprague-Dawley; D012160:Retina / Q000254:growth & development / Q000293:injuries / Q000473:pathology*; D013477:Superior Colliculi / Q000254:growth & development / Q000473:pathology* / Q000503:physiopathology; D015854:Up-Regulation / Q000502:physiology; D014795:Visual Pathways / Q000254:growth & development / Q000293:injuries / Q000473:pathology*