On the Rôle of the Pupillo-Constrictory Centers in the Adrenalinmydriasis and-Miosis

The Activity of the Cilio-Spinal Centers and Their Inhibition in Pupillary Light Reflex

“…In our previous report (13) it has been found that the impulse discharge of the pupillo-constrictory centers in the midbrain of the decerebrate cat is increased by intravenous administration of adrenalin. The effect of the drug in these experiments is attributed to either the direct action of the drug upon these centers themselves or the change of the blood stream in these centers brought about by the increase of the general blood pressure, because the action of reflex nature of the drug has been excluded.…”

The Activity of the Pupilloconstrictory Centers

“…Action potentials from a single or a few active units of the short ciliary nerve were recorded by using a similar method to that mentioned in the previous report (14).…”

“…In some cases a glass capillary microelectrode whose tip diameter was 2-5 micra and filled with Locke's solution was inserted into the isolated midbrain to record action potentials from the oculomotor nuclei by using the method described in the prevoius report (15 2. The inherent tonus of the deafferenated puPillo-constrictory centers This experiment is for the purpose of ascertaining whether the deafferenated pupillo-constrictory centers do discharge spontaneous impulses or not.…”

“…We have recently reported that the discharge pattern from the individual neuron of the pretectal area where the site of a synapse in the pathway concerned with pupillary light reflex is distinguishable into the six patterns, i.e., on-, off-and on-off-acceleratory patterns as well as on-, off-and on-off-inhibitory patterns (15 ) .…”