. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. C. Constricting, Head-type Response anterior stimulation D. Response Transformation Anterior US Posterior US 10 sec Figure 2. Transformation of siphon responses following noxious stimulation. The left column shows a cutaway view of the siphon and mantle organs in the intact animal (compare Fig. 1 A). The right column shows the mantle organs and CNS in a reduced preparation. The photocell monitors the breadth but not the length of the siphon. (A) Relaxed siphon. Weak test stimuli were applied to a midbody nerve at 1 min inter
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. C. Constricting, Head-type Response anterior stimulation D. Response Transformation Anterior US Posterior US 10 sec Figure 2. Transformation of siphon responses following noxious stimulation. The left column shows a cutaway view of the siphon and mantle organs in the intact animal (compare Fig. 1 A). The right column shows the mantle organs and CNS in a reduced preparation. The photocell monitors the breadth but not the length of the siphon. (A) Relaxed siphon. Weak test stimuli were applied to a midbody nerve at 1 min intervals. A noxious unconditioned stimulus (US), a 15 s sequence of strong shock, was delivered to either a tentacle nerve or a tail nerve. (B) Flanng response, typical of posterior stimulation. The photocell shows a negative deflection. (C) Constricting response typical of anterior stimulation. The photocell shows a positive deflection. (D) Examples of transformed responses. Top—flaring responses are converted to constricting responses after noxious anterior stimulation. Bottom—constricting responses are con- verted to flaring responses after noxious posterior stimulation (Erickson and Walters, 1988). ferent regions of the body. This response-specific noci- ceptive plasticity is expressed most clearly when noxious stimulation causes the animal to respond to a test stimulus with a qualitatively different response than it did before noxious stimulation (Erickson and Walters, 1988). Figure 2 shows examples of siphon responses being transformed into opposite responses following intense stimulation of nerves from the head or tail. Like sensitization, response transformation can be enhanced by associative training. The incidence and degree of transformation of motor re- sponses to particular test stimuli are preferentially in- creased if the test stimulus is repeatedly paired with a noxious stimulus (Walters, 1989; Hawkins el 1989). Mechanisms of Nociceptive Plasticity Mechani
Size: 1879px × 1330px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
