Synaptology of the cerebello-olivary pathway. Double labelling with anterograde axonal tracing and GABA immunocytochemistry in the rat.
The dentato-olivary projection has been ultrastructurally studied in rats that received a wheatgerm agglutinin-horseradish peroxidase (WGA-HRP) injection in the nucleus lateralis. Ultrathin sections containing the inferior olive have been double-labelled with the GABA-immunogold method. About 97% of the WGA-HRP labelled axon terminals are GABA-immunopositive. Most of them belong to a single type consisting of small boutons establishing symmetrical synapses on dendrites. Nevertheless, there is some morphological and neurochemical diversity among the labelled terminals, and particularly, a small contingent are GABA-immunonegative. Of the GABAergic dentato-olivary boutons, 4% occupy a privileged position, with synaptic contacts straddling two dendritic profiles linked by gap junctions. The strategic location of these inhibitory dentato-olivary synapses suggests that they can modulate the electrotonic coupling rate between sets of inferior olivary neurons.
Angaut
P
P
Histologie Normale et Pathologique du Système Nerveux, INSERM U-106, Hôpital de la Salpêtrière, Paris, France.
Sotelo
C
C
D000818:Animals; D002531:Cerebellum / Q000378:metabolism* / Q000648:ultrastructure; D006735:Horseradish Peroxidase; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D009411:Nerve Endings / Q000378:metabolism* / Q000648:ultrastructure; D009847:Olivary Nucleus / Q000378:metabolism* / Q000648:ultrastructure; D051381:Rats; D011919:Rats, Inbred Strains; D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; D014909:Wheat Germ Agglutinins; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; D014909:Wheat Germ Agglutinins; D005680:gamma-Aminobutyric Acid; D006735:Horseradish Peroxidase