778 



HANDBOOK OF PH'lSIOLOOY ' 



NEUROPHYSIOLOGY I 



relay nuclei 



pathway to dorsal column n\iclci, 400 

 patterns in, 399 



reticular formation and, 747 



tactile area 

 patterns, 401 



thermoreceptive neurons in, 435 

 Thermal energy 



receptor excitation by, 1 24 

 Thermal fibers, 444-455 



see also Cold fibers 



association with pain fibers, 484 



discharge, 446-453 



discharge and temperature, 447, 448 



latency to cooling, 452 



paradoxical discharge, 452 



temperature change and, 449, 450 

 Thermal receptors, 431-457 



acetylcholine and, 455 



adaptation, 456 



afferent ner\'e paths of, 435 



carbon dioxide, 455 



cold-blooded animals, 445 



depth in skin, 432 



excitation mechanism, 456, 457 



identification, 434 



intracutaneous temperature gradient, 



453 



invertebrates, 379, 380 



ischemia, 442, 443, 453 



location of, 431-435 



paradoxical responses, 443 



specificity of fibers, 444 



temperature change and, 449 

 Thermal sensations, 431-457 



central threshold for, 455 



cold 



non-thermal causes of, 454 

 paradoxical, 452 



Ebbecke phenomenon, 443 



hot, 444 



temperature change in skin, 438 



topography, 43 1 , 432 



warmth 



paradoxical, 453 



Weber's deception, 454 



Weber's phenomena, 453 



Weber's theory, 437, 443 

 Thermal thresholds 



temperature change and, 440 

 Threshold membrane potential ; see Mem- 

 brane potential 

 Threshold receptor potential: see Re- 

 ceptor potential 

 Tickling 



as related to pain, 498, 499 

 Tonal pattern discrimination 



auditory cortical ablation and, 597 

 Tone frequency 



response to, by cochlear ncrscs, 604 

 Tonic labyrinthine reflexes 



action of, 560 



otoliths and, 560 

 Tonic neck reflexes 



action of, 560 



otoliths and, 560 

 Touch-pressure system, 387-426 



see also Cutaneous sensations; Tactile 

 system; Skin receptors 



adaptation in, 403 



in deep fascia, 415 



medial lemniscal system and, 403 

 Touch receptors 



invertebrate, 380 



sympathetic influence, 742 

 Transducer action 



synaptic membranes and, 154, 156, 157, 

 161 



synaptic electrogenesis and, 189 



tactile receptors and, 380 

 Transmission 



see also Ephaptic transmission; Synaptic 

 transmission; Nerve impulse; Con- 

 duction 



nerve conduction and, 62, 65 



between neurons, 65 



electrical versus chemical, 2 1 7 



integrative activity and, 149 



neuromuscular, 199-253 

 autonomic, 215-235 

 invertebrate, 239-253 

 skeletal, 199-235 



postsynaptic potential and, 149 

 Transmission, autonomic neuroeffector : 

 see Transmitter substances; Chemical 

 transmission 

 Transmittance, spectral 



eye and, 666 

 Tiansmitter substances 



ee also Adrenergic transmitter; Cho- 

 linergic transmitter 



action Ca on, 153 



action Mg on, 153 



blood content of, 234 



characterization, 178 



crustacean, 243 



desensitization at synapse, 157 



excitatory, 7 1 



histamine, 141 



identification, 178 



inhibitory, 71 



insect, 247 



localized action, 181 



mode of action, 166, 180, 233 



molluscs, 248 



requirements, 1 79 



synaptic specificity, 181 



urine content of, 234 

 Triad response 



definition, 662 

 Tympanic membrane 



function, 568 

 Tympanal organs 



in invertebrates, 382 



Tympanic reflex 



characterization, 568 



Ultraviolet light 



aphakic eye and, 666 



eye sensitivity to, 641 

 Unicellular organisms 



photosensitivity in, 623 

 Utricle 



anatomy of, 550 



function, 557 



Vestibular mechanism, 549-562 



see also Equilibrium; Labyrinthectomy 



action on ocular muscles, 559 



adaptation, 555 



anatomy of labyrinth, 550 



ascending pathways from, 558-560 



caloric stimulation. 556 



connections with brain, 558 



cortical projection, 559 



destruction of, 561, 562 



discharge after stimulation, 555 



galvanic stimulation, 556 



mode of action of, 552 



muscle contraction and, 561 



nystagmus and, 558 



postural reflexes and, 560 



receptor cells, 552 



reticular formation and, 561 



reflexes from, 558-561 



sound stimulation of, 557 

 Vestibular nerve 



electrical stimulation of, 559 



origin, 552 

 Vestibular nuclei 



connections, 558 



fiber paths from, 558 

 Vestibulospinal tract 



anatomy of, 560 

 Vibration sense 



human, 374 



insect, 374 



invertebrate, 380 

 Vibrational stimulation 



of utricle, 557 

 Vision, 617-759 



see also Brightness vision; Image forma- 

 tion; Retinal image; Eye; Retina; 

 Cones; Rods 



alternation of response theory, 734 



apparent movement, 737 



binocular rivalry, 737 



brightness contrast and, 737 



central mechanisms, 713-739 

 modes of study, 7 1 4 



color vision, 738, 739 



cortical facilitation, 733 



cortical on-off responses, 730 



definition of, 713, 714 



flicker, 729-732 



