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Reflexes to sacral parasympathetic neurones concerned with micturition in the cat
Author(s) -
de Groat W. C.,
Ryall R. W.
Publication year - 1969
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.1969.sp008683
Subject(s) - reflex , spinal cord , chloralose , inhibitory postsynaptic potential , cholinergic , medicine , urination , neuroscience , triceps reflex , stimulation , axon reflex , anatomy , anesthesia , withdrawal reflex , psychology , urinary system
1. Reflexes to sacral parasympathetic neurones were studied by electrophysiological techniques in decerebrate, in chloralose‐anaesthetized, and in chronic spinal cats. 2. Excitatory reflexes from pelvic nerve and sacral somatic afferent nerve fibres were present before and after chronic transection of the spinal cord, but the latencies differed markedly. It was concluded that the long‐latency reflexes observed when the spinal cord was intact involved long‐loop reflexes to the brain‐stem. The weak, short‐latency reflexes in the chronic spinal cat were never observed when the spinal cord was intact and could be due to reorganized spinal connexions. The short‐latency reflexes are probably unimportant in normal micturition. 3. Stimulation of afferent fibres in the pelvic or sacral somatic nerves produced short‐latency inhibitory post‐synaptic potentials (IPSPs) and inhibition of discharges in parasympathetic neurones. This inhibition was due to a spinal reflex. 4. A local reflex was demonstrated in the pelvic plexus. This was probably a cholinergic axon reflex, but the remote possibility that it was a local cholinergic reflex involving sensory neurones in the bladder wall has not been excluded.