The degeneration of the excitatory climbing fibers enhances [3H]MK-801 and [3H]CGP 39653 binding sites in the rat cerebellar cortex.
The effect of a single injection of 3-acetylpyridine (3-AP), which led to a degeneration of the excitatory cerebellar climbing fibers, was studied on the binding of [3H]MK-801, a non-competitive NMDA antagonist, in the rat cerebellar cortex. The same treatment increased also the binding of [3H]CGP 39653, a new NMDA competitive antagonist. Saturation isotherms showed a significant increase of the maximal number of binding sites (Bmax) for [3H]CGP 39653 and [3H]MK-801 (+48 and 36% respectively) with no change in the affinity 4-9 days after the administration of 3-AP. Our data demonstrate that in the cerebellar cortex both NMDA recognition site labelled by [3H]CGP 39653 and its modulatory site labelled by [3H]MK-801 may undergo plastic changes when the glutamatergic receptors and transmission are denervated.
Department of Experimental Biology, University of Cagliari, Italy.
S
S
Mariangela
G A
GA
Cristina
F M
FM
Cristina
M
M
Costantino
B
B
Giovanni
D015763:2-Amino-5-phosphonovalerate / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D002525:Cerebellar Cortex / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D016291:Dizocilpine Maleate / Q000494:pharmacology*; D007700:Kinetics; D008297:Male; D009410:Nerve Degeneration / Q000502:physiology*; D009412:Nerve Fibers / Q000502:physiology*; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects*; D009435:Synaptic Transmission / Q000187:drug effects
D011725:Pyridines; D016194:Receptors, N-Methyl-D-Aspartate; C010835:3-acetylpyridine; C069052:CGP 39653; D016291:Dizocilpine Maleate; D015763:2-Amino-5-phosphonovalerate