The cardiac response of the crabChasmagnathus granulatusas an index of sensory perception

Abstract

SUMMARYWhen an animalʼs observable behavior remains unaltered, one can be misled in determining whether it is able to sense an environmental cue. By measuring an index of the internal state, additional information about perception may be obtained. We studied the cardiac response of the crab Chasmagnathus to different stimulus modalities: a light pulse, an air puff, virtual looming stimuli and a real visual danger stimulus. The first two did not trigger observable behavior, but the last two elicited a clear escape response. We examined the changes in heart rate upon sensory stimulation. Cardiac response and escape response latencies were also measured and compared during looming stimuli presentation. The cardiac parameters analyzed revealed significant changes (cardio-inhibitory responses) to all the stimuli investigated. We found a clear correlation between escape and cardiac response latencies to different looming stimuli. This study proved useful to examine the perceptual capacity independently of behavior. In addition, the correlation found between escape and cardiac responses support previous results which showed that in the face of impending danger the crab triggers several coordinated defensive reactions. The ability to escape predation or to be alerted to subtle changes in the environment in relation to autonomic control is associated with the complex ability to integrate sensory information as well as motor output to target tissues. This ʻfear, fight or flightʼ response gives support to the idea of an autonomic-like reflexive control in crustaceans.

Characterization of the cardiac ganglion in the crab Neohelice granulata and immunohistochemical evidence of GABA-like extrinsic regulation

“…20 mediated by GABA as Picrotoxin, a non competitive GABAergic antagonist, partially abolished the CIR already described in this decapod (Hermitte and Maldonado, 2006;Burnovicz et al, 2009;Burnovicz and Hermitte, 2010).…”

“…Cardio-inhibitory responses (CIR) occur in many animal groups, such as mollusks (Wells, 1979;King and Adamo, 2006), crustaceans (Cuadras, 1980;Grober, 1990a;Burnovicz et al, 2009), fish (Axelsson et al, 1987;Axelsson et al, 1989;Ide and Hoffmann, 2002), amphibians (Laming and Austin, 1981), birds (Cohen and Macdonald, 1971) and mammals (Smith et al, 1981). Several studies have attempted to explain a possible functional role of this transient cardiac inhibition in response to external stimulation.…”

“…CIR has been associated both with attentional phenomena in vertebrates (Powell, 1994) and with the orienting response in invertebrates (Shuranova and Burmistrov, 1996). In addition, CIR has been described as a component of the "death-feigning behavior" in decapod crustaceans (McMahon and Wilkens, 1972) and as an index of sensory perception and evidence of a neuroautonomic response in the crab Neohelice granulata (Hermitte and Maldonado, 2006;Burnovicz et al, 2009;Burnovicz and Hermitte, 2010). In any case, its prevalence across invertebrates and vertebrates leads to the assumption that it has a universally adaptive function.…”

Cardiac response of the hydrothermal vent crab Segonzacia mesatlantica to variable temperature and oxygen levels

“…Wilkens (1993) reports that it is maintained in isolated hearts, provided that the partial pressure of oxygen is sufficient. The overall shape of the EKG resembles that recorded for Bythograea thermydron, another hydrothermal vent crab studied by Mickel and Childress (1982) and other, shallow-water, crabs (Burnovicz et al, 2009). For B. thermydron, the authors did not consider changes in amplitude as a function of pressure because the amplitude seemed to be affected by the time elapsed since electrode implantation and pressure affected the electrical connectors in the vessel.…”

Experimental setup influences the cardiovascular responses of decapod crustaceans to environmental change

“…Although the cardiac output is influenced by changes in both HR and stroke volume, (which can be modulated independent of one another), measurement of HR alone continues to provide important information on the metabolic changes and responses to environmental perturbations (Stillman 2004: McGaw and Reiber 2015: McLean and Todgham 2015, acute stress responses (Burnovicz et al 2009) and for ecotoxicology studies (Bamber andDepledge 1997: Handy andDepledge 1999) in decapod crustaceans.…”