Summary
The spiracular sense organs of the little skate,Raja erinacea, and the smooth dogfish,Mustelus canis, respond to movements of the hyomandibula-cranial joint. Afferent activity was recorded from the spiracular organ nerve in isolated preparations consisting of at least part of the cranium, the hyomandibula, and the spiracular organ and nerve. Afferents are excited by hyomandibular flexion at its joint with the cranium. Single unit recordings in the little skate revealed a single class of units that were slowly adapting, and had a regular firing pattern. Single unit firing rate increased up to about 70 spikes/s during hyomandibular flexion from a spontaneous rate at rest of 15–20 spikes/s, and could often be silenced by hyomandibular extension. The direction of excitation is consistent with the orientation of the hair cell ciliary bundles observed in morphological studies (Barry et al. 1988).
Local deformations of the cupula are sufficient to excite or inhibit primary afferent firing, and volume changes in the spiracular organ as a whole are not necessary. The spiracular organs are relatively insensitive to electrical stimuli, vibration, or water movement. In conclusion, the spiracular organ functions as a sensitive joint receptor.
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References
Agar WE (1906) The spiracular gill cleft inLepidosiren andProtopterus. Anat Anz 28:298–304
Ballintijn CM, Roberts JL (1976) Neural control and proprioceptive load matching in reflex respiratory movements of fishes. Fed Proc 35:1983–1991
Barry MA, Boord RL (1984) The spiracular organ of sharks and skates: Anatomical evidence indicating a mechanoreceptive role. Science 226:990–992
Barry MA, Hall DH, Bennett MVL (1988) The elasmobranch spiracular organ. I. Morphological studies. J Comp Physiol A 163:85–92
Baumann M, Roth A (1986) The Ca++ permeability of the apical membrane of neuromast hair cells. J Comp Physiol A 158:681–688
Bullock TH, Bodznick DA, Northcutt RG (1983) The phylogenetic distribution of electroreception: evidence for convergent evolution of a primitive vertebrate sense modality. Brain Res Rev 6:25–46
Clusin WT, Bennett MVL (1977) Calcium activated conductance in skate electroreceptors: voltage clamp experiments. J Gen Physiol 69:145–182
Münz H (1985) Single unit activity in the peripheral lateral line system of the cichlid fishSarotherodon niloticus L. J Comp Physiol A 157:555–568
Münz H, Claas B, Fritzsch B (1984) Electroreceptive and mechanoreceptive units in the lateral line system of the axolotlAmbystoma mexicanum. J Comp Physiol A 154:33–44
Murray RW (1956) The response of the lateralis organs ofXenopus laevis to electrical stimulation by direct current. J Physiol (Lond) 134:408–420
Norris HW, Hughes SP (1920) The spiracular sense-organ in elasmobranchs, ganoids and dipnoans. Anat Rec 18:205–209
Sand A (1937) The mechanism of the lateral sense organs of fishes. Proc R Soc Lond 1373:472–495
Satchell GH, Way HK (1962) Pharyngeal proprioceptors in the dogfishSqualus acanthias L. J Exp Biol 39:243–250
Strelioff D, Honrubia V (1978) Neural transduction inXenopus laevis lateral line system. J Neurophysiol 41:423–444
Tong S, Bullock TH (1984) Physiological properties of the electro- and mechanoreceptors in catfishIctalurus nebulosus. Sci Sinica B 27:1023–1028
Wright RR (1885) Some preliminary notes on the anatomy of fishes. Am Nat 19:187–190
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Barry, M.A., White, R.L. & Bennett, M.V.L. The elasmobranch spiracular organ. J. Comp. Physiol. 163, 93–98 (1988). https://doi.org/10.1007/BF00612000
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DOI: https://doi.org/10.1007/BF00612000