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Full-Text Articles in Veterinary Physiology
Characterisation Of Chemosensory Trigeminal Receptors In The Rainbow Trout, Oncorhynchus Mykiss: Responses To Chemical Irritants And Carbon Dioxide, Jessica J. Mettam, Catherine R. Mccrohan, Lynne U. Sneddon
Characterisation Of Chemosensory Trigeminal Receptors In The Rainbow Trout, Oncorhynchus Mykiss: Responses To Chemical Irritants And Carbon Dioxide, Jessica J. Mettam, Catherine R. Mccrohan, Lynne U. Sneddon
Veterinary Science and Medicine Collection
Trigeminally innervated, mechanically sensitive chemoreceptors (M) were previously identified in rainbow trout, Oncorhynchus mykiss, but it is not known whether these receptors are responsive only to noxious, chemical irritants or have a general chemosensory function. This study aimed to characterise the stimulus–response properties of these receptors in comparison with polymodal nociceptors (P). Both P and M gave similar response profiles to acetic acid concentrations. The electrophysiological properties were similar between the two different afferent types. To determine whether the receptors have a nociceptive function, a range of chemical stimulants was applied to these receptors, including non-noxious stimuli such as ammonium …
Nociception In Fish: Stimulus–Response Properties Of Receptors On The Head Of Trout Oncorhynchus Mykiss, Paul J. Ashley, Lynne U. Sneddon, Catherine R. Mccrohan
Nociception In Fish: Stimulus–Response Properties Of Receptors On The Head Of Trout Oncorhynchus Mykiss, Paul J. Ashley, Lynne U. Sneddon, Catherine R. Mccrohan
Veterinary Science and Medicine Collection
This study examined stimulus–response properties of somatosensory receptors on the head of rainbow trout, Oncorhynchus mykiss, using extracellular recording from single cells in the trigeminal ganglion. Of 121 receptors recorded from 39 fish, 17 were polymodal nociceptors, 22 were mechanothermal nociceptors, 18 were mechanochemical receptors, 33 were fast adapting mechanical receptors and 31 were slowly adapting mechanical receptors. Mechanical thresholds were higher in polymodal nociceptors than in either slowly adapting or fast adapting mechanical receptors, whereas thermal thresholds of mechanothermal nociceptors were higher than those of polymodal nociceptors. Polymodal nociceptors and mechanochemical receptors gave similar responses to topical applications of …
Do Fishes Have Nociceptors? Evidence For The Evolution Of A Vertebrate Sensory System, Lynne U. Sneddon, Victoria A. Braithwaite, Michael J. Gentle
Do Fishes Have Nociceptors? Evidence For The Evolution Of A Vertebrate Sensory System, Lynne U. Sneddon, Victoria A. Braithwaite, Michael J. Gentle
Veterinary Science and Medicine Collection
Nociception is the detection of a noxious tissue-damaging stimulus and is sometimes accompanied by a reflex response such as withdrawal. Pain perception, as distinct from nociception, has been demonstrated in birds and mammals but has not been systematically studied in lower vertebrates. We assessed whether a fish possessed cutaneous nociceptors capable of detecting noxious stimuli and whether its behavior was sufficiently adversely affected by the administration of a noxious stimulus. Electrophysiological recordings from trigeminal nerves identified polymodal nociceptors on the head of the trout with physiological properties similar to those described in higher vertebrates. These receptors responded to mechanical pressure, …
Trigeminal Somatosensory Innervation Of The Head Of A Teleost Fish With Particular Reference To Nociception, Lynne U. Sneddon
Trigeminal Somatosensory Innervation Of The Head Of A Teleost Fish With Particular Reference To Nociception, Lynne U. Sneddon
Veterinary Science and Medicine Collection
Trigeminal somatosensory receptors have not been characterised in teleost fish and studies in elasmobranchs have failed to identify nociceptors. The present study examined the trigeminal nerve of a teleost fish, the rainbow trout (Oncorhynchus mykiss) to determine what types of somatosensory receptors were present on the head of the trout specifically searching for nociceptors. Single unit recordings were made from receptive fields on the head of the fish innervated by the trigeminal nerve. Each receptive field was tested for sensitivity to mechanical, thermal and chemical stimulation. Five different receptor types were found: fast adapting receptors responding to mechanical stimulation; slowly …
Amputation Of Vibrissae In Show Dogs, Thomas E. Mcgill
Amputation Of Vibrissae In Show Dogs, Thomas E. Mcgill
Veterinary Science and Medicine Collection
Dogs of many different breeds competing in the show-ring are routinely subjected to amputation of the vibrissae, organs that are commonly and incorrectly called "whiskers." This procedure is thought to give the animal's head a cleaner look, which in turn supposedly increases its chances of winning. There are several tricks involved in "whisker trimming" since the animals can retract each vibrissae at least one-quarter inch. Furthermore, they often object strenuously to the operation.