. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 508 DANIEL L. ALKON 1970; Epstein and Tauc, 1970; Peretz, 1970; Castellucci et al, 1970; Carew et al, 1971). Strumwasser, Jacklet, and others have used Aplysia to study neuronal mechanisms of circadian rhythms of behavior (Strumwasser, 1965; Strumwasser ctal., 1969; Jacklet, 1977). ' During the last 10 years other investigators have turned to a number of gastro- pod molluscs for examples of associative learning behavior mediated by analyzable neural pathways. With the exception of the nudibranch Hermissenda crassicornis (Fig
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 508 DANIEL L. ALKON 1970; Epstein and Tauc, 1970; Peretz, 1970; Castellucci et al, 1970; Carew et al, 1971). Strumwasser, Jacklet, and others have used Aplysia to study neuronal mechanisms of circadian rhythms of behavior (Strumwasser, 1965; Strumwasser ctal., 1969; Jacklet, 1977). ' During the last 10 years other investigators have turned to a number of gastro- pod molluscs for examples of associative learning behavior mediated by analyzable neural pathways. With the exception of the nudibranch Hermissenda crassicornis (Fig. 2; Alkon, 1974a, b) these molluscs experience chemical (and/or touch) stim- ulation of the tentacle or oral veil during the training paradigm. In considering possible preparations it seemed reasonable to me that to under- stand quantitatively how a nervous system causes associative learning behavior, it would be advantageous to use natural stimuli transduced by sensory receptors during an organism's normal life cycle. The effects of these stimuli might then be followed step by step from the receptors to interneurons and ultimately to motor neurons and muscular activity. Gastropods were attractive because of their relatively small number of neurons yet fairly elaborate behavioral capability. It also seemed reasonable that with such a small number of neurons, the animal was more likely to be capable of intermodal than of intramodal sensory associations. Natural stimuli for the training regimen seemed important to me for another reason : the patterns of natural stimuli encountered by the animal in its environment should determine the range of possible learned behaviors adaptive within a given biological. FIGURE 2. The nudibranch mollusc Hermissenda crassicornis. Note the small black spot (the right eye) at the base of the lower rhinophore. Length of the animal is ~ 4 Please note that these images are extracted from scanned page images that may have been digitally enhanced f
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
