Intraventricular administration of substance p increases the dendritic arborisation and the synaptic surfaces of Purkinje cells in rat's cerebellum.
Substance P was infused in the lateral ventricles of twenty Lewis rats for twenty days. On the twentieth day the animals were sacrificed and the cerebellar cortex was processed for electron microscopy. The ultrastructural morphometric analysis revealed that the Purkinje cell dendritic arborisation and the number of the synapses between the parallel fibres and the Purkinje cell dendritic spines were much higher than in control animals. Numerous unattached spines of the secondary and tertiary dendritic branches of the Purkinje cells were also seen in the molecular layer either free or surrounded by astrocytic sheath. The increased number of synapses between the Purkinje cell dendrites and the parallel fibres in the animals, which received substance P intraventricularly, in correlation to control animals, supports a neurotrophine-like activity of the substance P in the mammalian cerebellum, enforcing the pre-programmed capability of the Purkinje cells to develop new synaptic surfaces.
Baloyannis
S J
SJ
Department of Neurology, Aristotelian University, Thessaloniki, Greece.
Costa
V
V
Deretzi
G
G
Michmizos
D
D
D000818:Animals; D001667:Binding, Competitive / Q000502:physiology; D002462:Cell Membrane / Q000187:drug effects / Q000648:ultrastructure; D002531:Cerebellum / Q000187:drug effects* / Q000648:ultrastructure; D003712:Dendrites / Q000187:drug effects*; D004333:Drug Administration Routes; D005260:Female; D008297:Male; D008565:Membrane Proteins / Q000187:drug effects*; D011689:Purkinje Cells / Q000187:drug effects* / Q000648:ultrastructure; D051381:Rats; D018040:Receptors, Neurokinin-1 / Q000187:drug effects; D013373:Substance P / Q000008:administration & dosage / Q000494:pharmacology*; D013570:Synaptic Membranes / Q000187:drug effects* / Q000648:ultrastructure
D008565:Membrane Proteins; D018040:Receptors, Neurokinin-1; D013373:Substance P