Charles H. Page

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Recordings were made from postural-control motor nerves with antagonistic functions in the crayfish abdomen through flexible suction electrodes. During unrestrained flexion of the abdomen, output from the tonic stretch receptor neuron of RM(1),(SR(1)) is sufficient to drive an extensor motor unit in the same segment. However, this intrasegmental(More)
1. Stretch stimulation of the abdominal muscle receptor organ of the lobster Homarus americanus initiated spike discharge of its tonic sensory neuron (SR1). This sensory response evoked a series of tonic postural reflex responses in the motor neurons that innervate the superficial extensor and flexor muscles of the abdominal postural system. The type of(More)
The gills of Limulus are ventilated by a metachronal rhythm of movements of five pairs of gill plates. A gill plate is promoted and remoted by action of alternating nerve impulse bursts to antagonist promotor and remotor muscles. The motor output pattern is centrally generated, requiring no sensory feedback. Intracellularly recorded rhythmic activity of(More)
Intersegmental interneurons in the lobster second abdominal ganglion were differentially stained by simultaneously backfilling their axons in the anterior and posterior hemiconnectives with nickel and cobalt ions. When precipitated with rubeanic acid the nickel and cobalt formed different colors in the cell bodies depending upon the location of the axon(s)(More)
1. Using intracellular recording and dye-filling techniques, a survey of postural interneurons was undertaken by impaling their somata in the 2nd abdominal ganglion of lobster. 2. During the course of study approximately fourty different intersegmental interneurons in this ganglion were sampled. Of these, 8 evoked unique, patterned responses in the postural(More)
The mechanosensory innervation of the lobster (Homarus americanus) swimmeret was examined by electrophysiologically recording afferent spike responses initiated by localized mechanical stimulation of the caudal surface of the swimmeret. Two functional groups of subcuticular hypodermal mechanoreceptors innervate the swimmeret. Afferents of one group(More)
1. The crayfishProcambarus clarkii almost always extends its abdomen when it is lifted up from the aquarium floor into the water column. 2. Under identical stimulus conditions bothOrconectes rusticus andO. virilis rarely respond by full abdominal extension. Usually they move their abdomens to a position intermediate to extension and flexion. 3. Comparison(More)
1. Responses of oxygen-sensitive units in the prosomal haemal nerve of Limulus polyphemus were examined while varying the oxygen content of sea water bathing the intercoxal cuticle. 2. When exposed to high oxygen levels these units units maintained a continuous background discharge of spikes. Unit activity was inhibited when oxygen content decreased. Upon(More)
1. The influence of mechanosensory stimulation of a second segment swimmeret upon the abdominal postural program was examined in an isolated abdominal nerve cord-swimmeret preparation. The swimmeret was stimulated in several different ways to assess the extent of influence exerted on abdominal positioning. 2. Localized tactile stimulation of the swimmeret(More)