A study was made of the mechanism producing symptoms of the cervical syndrome initiated by electrical stimulation of the great occipital nerve (GON) and the cervical sympathetic nerve (CSN) of rabbits and also an attempt to make clear the mechanism of the action of CDPcholine and Meclofenoxate was undertaken.
Experiment I: The unit disch arge of the reticular formation. The frequency of unit discharges increased through GON and CSN stimulation at 100Hz. It was demonstrated that the above changes were inhibited following the administration of CDP-choline and Meclofenoxate.
Experiment II: The recruiting response due to the stimulation of VA. Its amplitude decreased through GON stimulation at 3Hz, increased through GON stimulation at 100Hz, decreased through CSN stimulation at 3Hz and increased and decreased through CSN stimulation at 100Hz. It was also demonstrated that the increase through GON stimulation at 100Hz was inhibited following the administration of CDP-choline and Meclofenoxate.
Experiment III: The average evoked potential in the cerebral cortex. The amplitude on early component (N1, N2, N3) decreased through GON stimulation at 3Hz, increased through GON stimulation at 100Hz and increased and decreased through CSN stimulation. It was demonstrated that the increase through GUN stimulation at 100Hz was inhibited following the administration of Meclofenoxate.
Experiment IV: The average evoked potential in the hippocampus. The amplitude on late component (HN5, HN6) increased through GON and CSN stimulation at 100Hz. It was also demonstrated that the above changes flattened out following the administration of CDP-choline and Meclofenoxate.
Experiment V: The evoked muscular discharge due to the stimulation of cerebral cortex. The inhibitory effect on forelimbs was noticed through GON stimulation and the facilitatory effect was noticed through CSN stimulation. It was also demonstrated that the above change through CSN stimulation at 100Hz was inhibited following the administration of CDP-choline and Meclofenoxate.
Experiment VI: The evoked muscular discharge due to the stimulation of hippocampus. The inhibitory effect on fore and hindlimbs was noticed through GON stimulation, the inhibitory effect on forelimbs and the facilitatory and inhibitory effect on hindlimbs was noticed through CSN stimulation at 3Hz and the facilitatory and inhibitory effect on fore and hindlimbs was noticed through CSN stimulation at 100Hz. It was also demonstrated that the inhibitory effect through GON stimulation flattened out following the administration of CDP-choline and changed the facilitatory effect following the administration of Meclofenoxate.
Experiment VII: M wave and H wave. The ampuli tude of M wave and H wave decreased through GON and CSN stimulation. It was also demonstrated that the above changes changed the facilitatory effect following the administration of CDP-choline and the change through GON stimulation flattened out following the administration of Meclofenoxate.
Experiment VIII: Gastric movement. Gastric move m ent was inhibited GON and CSN stimulation. It was also demonstrated that the inhibition through GON stimulation changed the facilitatory effect following the administration of CDP-choline.
Experiment IX: The vertebral and carotid blood flow. Their blood flow through GON stimulation remained almost unchanged, but those through CSN stimulation remarkably decreased.