Abstract
It is well-known that anatomically, the cerebellum has a very uniform and stereotyped structure with geometrical precision. The Purkinje cell, which provides the unique output from the cerebellum, receives two excitatory inputs : one is from parallel fibers, axons of the granule cells, and the other is from climbing fibers which originate at the inferior live. In order to characterize the neurotransmitter of the climbing fibers, the electrophysiological properties of Purkinje cells were first studied by intradendritic as well as intrasomatic recordings from Purkinje cells of guinea pig cerebellar slices. Comparison of the reversal properties, ionic dependency and the sensitivity to various antagonists of the climbing fiber responses with those of responses to L-glutamate and L-aspartate supports the previous suggestion based on the bio- and histochemical observations that L-aspartate is more likely than L-glutamate to be the neurotransmitter of the climbing fiber synapses. The Purkinje cell is also reported to contain a relatively high activity of NADP-linked prostaglandin (PG) D2 dehydrogenase and abundant PGD2 binding sites. PGs potentiate the actions of both excitatory and inhibitory neurotransmitter candidates in our experimental system. In this article, the role of prostaglandins in the neuronal transmission in the cerebellum is also described.
