Summary
This study examines the nature of the efferent projection of omnipause neurons (OPNs) in the midline pontine tegmentum to medium-lead burst neurons (BNs) in the Forel's field H (FFH), both of which exhibit activities related to vertical eye movements, using chronically prepared alert cats. Antidromic spikes of the BNs evoked by oculomotor nucleus stimulation were suppressed by shortly preceding (less than 5 ms) microstimulation within the OPN area including actual recording sites of OPNs. Many OPNs were antidromically activated by microstimulation at recording sites of the BNs. Furthermore, systematic tracking in and around the FFH with the stimulating microelectrode substantiated that the OPNs issued axonal branches within the BN area. These results suggest direct inhibitory projection of OPNs to the BNs.
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Büttner U, Büttner-Ennever JA, Henn V (1977) Vertical eye movement related unit activity in the rostral mesencephalic reticular formation of the alert monkey. Brain Res 130: 239–252
Curthoys IS, Markham CH, Furuya N (1984) Direct projection of pause neurons to nystagmus-related excitatory burst neurons in the cat pontine reticular formation. Exp Neurol 83: 414–422
Curtis DR, Eccles JC (1959) The time courses of excitatory and inhibitory synaptic actions. J Physiol 145: 529–546
Evinger C, Kaneko CRS, Fuchs AF (1982) Activity of omnipause neurons in alert cats during saccadic eye movements and visual stimuli. J Neurophysiol 47: 827–844
Furuya N, Markham CH (1982) Direct inhibitory synaptic linkage of pause neurons with burst inhibitory neurons. Brain Res 245: 139–143
Hikosaka O, Igusa Y, Nakao S, Shimazu H (1978) Direct inhibitory synaptic linkage of pontomedullary reticular burst neurons with abducens motoneurons in the cat. Exp Brain Res 33: 337–352
Igusa Y, Sasaki S, Shimazu H (1980) Excitatory premotor burst neurons in the cat pontine reticular formation related to the quick phase of vestibular nystagmus. Brain Res 182: 451–456
Keller EL (1974) Participation of medial pontine reticular formation in eye movement generation in monkey. J Neurophysiol 37: 316–332
King WM, Fuchs AF (1979) Reticular control of vertical saccadic eye movements by mesencephalic burst neurons. J Neurophysiol 42: 861–876
King WM, Precht W, Dieringer N (1980) Afferent and efferent connections of cat omnipause neurons. Exp Brain Res 38: 395–403
Langer TP, Kaneko CRS (1983) Efferent projection of the cat oculomotor reticular omnipause neuron region: an autoradiographic study. J Comp Neurol 217: 288–306
Llinás R, Terzuolo CA (1964) Mechanisms of supraspinal actions upon spinal cord activities. Reticular inhibitory mechanisms on alpha-extensor motoneurons. J Neurophysiol 27: 579–591
Nakao S, Curthoys IS, Markham CH (1980) Direct inhibitory projection of pause neurons to nystagmus-related pontomedullary reticular burst neurons in the cat. Exp Brain Res 40: 283–293
Nakao S, Sasaki S, Shimazu H (1977) Nuclear delay of impulse transmission in abducens motoneurons during fast eye movements of visual and vestibular origin in alert cats. J Neurophysiol 40: 1415–1423
Nakao S, Shiraishi Y (1983) Excitatory and inhibitory synaptic inputs from the medial mesodiencephalic junction to vertical eye movement-related motoneurons in the cat oculomotor nucleus. Neurosci Lett 42: 125–130
Nakao S, Shiraishi Y (1985) Direct excitatory and inhibitory synaptic inputs from the medial mesodiencephalic junction to motoneurons innervating extraocular oblique muscles in the cat. Exp Brain Res 61: 62–72
Nakao S, Shiraishi Y, Oikawa T (1986) Vertical eye movement-related neurons in the cat medial mesodiencephalic junction: firing pattern, location and projection to oculomotor and trochlear nuclei. Abstracts for Satellite Meeting of 30th International Congress of International Union of Physiological Sciences: Developments in Oculomotor Research, p 77
Robinson DA (1975) Oculomotor control signals. In: Lennerstrand G, Bach-y-Rita P (eds) Basic mechanisms of ocular motility and their clinical implications. Pergamon Press, New York, pp 337–374
Suzuki H, Azuma M (1976) A glass-insulated “Elgiloy” microelectrode for recording unit activity in chronic monkey experiments. Electroenceph Clin Neurophysiol 41: 93–95
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Nakao, S., Shiraishi, Y., Oda, H. et al. Direct inhibitory projection of pontine omnipause neurons to burst neurons in the Forel's field H controlling vertical eye movement-related motoneurons in the cat. Exp Brain Res 70, 632–636 (1988). https://doi.org/10.1007/BF00247612
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DOI: https://doi.org/10.1007/BF00247612