Response properties of cerebellar neurons to stimulation of the frog glossopharyngeal nerve and tongue.
The cerebellum receives information from many kinds of sensory organs (muscle, somatosensory, auditory, vestibular, visual) as well as from the autonomic system. The cerebellum presumably has a role in the control of tongue movement and salivary secretion. However, the relationship between cerebellar neuron activity and tongue sensation has not been investigated previously. In the present study, negative cerebellar field potentials in the molecular layer and single unit responses of Purkinje cells induced by electrical stimulation of the bullfrog glossopharyngeal (IXth) nerve or tongue surface were investigated. The interaction between IXth nerve stimulation and natural (taste and touch) stimulation of the tongue in their effects on cerebellar neuron activity were investigated. The negative field potentials were potentiated by a brief train of electrical pulses to the tongue or IXth nerve. With electrical stimulation of the tongue surface, several fungiform papillae were needed to elicit cerebellar field potentials. The latency of Purkinje cells following IXth nerve stimulation was 44.4-53.6 msec for complex spikes, whereas for simple spikes two maxima were seen, with mean values at 33.9-36 msec and 96.8 msec. A preceding electrical stimulation of the IXth nerve depressed the negative field potentials or Purkinje cell complex spike responses induced by test stimulation of the IXth nerve. These depressive effects were also seen following a preceding natural stimulation of the tongue and were dependent upon the type of preceding stimulation. The depressive effects were produced by preceding stimulation with NaCl, CaCl2, water, and touch, but not with quinine and acetic acid stimulation. These results clearly demonstrate that gustatory and tactile signals from the tongue can influence cerebellar neuron activity.
D000085:Acetates; D019342:Acetic Acid; D000200:Action Potentials; D000818:Animals; D002525:Cerebellar Cortex / Q000502:physiology*; D004558:Electric Stimulation; D005930:Glossopharyngeal Nerve / Q000502:physiology*; D010812:Physical Stimulation; D011689:Purkinje Cells / Q000502:physiology*; D011803:Quinine; D011892:Rana catesbeiana / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D012965:Sodium Chloride; D013395:Sucrose; D013649:Taste / Q000502:physiology; D014059:Tongue / Q000294:innervation* / Q000502:physiology
D000085:Acetates; D012965:Sodium Chloride; D013395:Sucrose; D011803:Quinine; D019342:Acetic Acid