Fri, 08 Aug 2008 19:42:23 BST CiteULike: brembs' Schwarz http://www.citeulike.org/user/brembs/author/Schwarz CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/brembs/article/3063021 <i>J Neurosci, Vol. 6, No. 5. (1986), 1513-27.</i><br /><br />Feeding behavior in Aplysia fasciata and A. oculifera is modified by pairing the behavior with reinforcing consequences. Successful and unsuccessful attempts to transfer food from the buccal cavity to the crop act as positive and negative reinforcers, respectively. A number of changes in feeding behavior occur as a result of pairing of feeding with the negative reinforcer: feeding responses become less effective in leading to the entry of food into the buccal cavity; when food does enter the buccal cavity, it exits sooner; swallowing responses after food entry are less likely to occur; Aplysia eventually cease responding to food. Pairing successful transfer of food into the crop with feeding behavior produces opposite effects. Behavioral change is specific to pairing, as shown by lack of change when reinforcement is explicitly unpaired with feeding behavior. Behavioral change is specific to foods with a particular taste and texture; generalization to alternate foods was not observed. In spite of cessation of feeding, animals remain aroused, as shown by low response latency to alternate foods. Memory of response change persists for at least 48 hr. Learned changes of feeding behavior in Aplysia in response to edible and inedible foods AJ Susswein M Schwarz E Feldman J Neurosci, Vol. 6, No. 5. (1986), 1513-27. 2008-07-30T12:57:46-00:00 1986 J Neurosci 6 5 1513-27 animal aplysiaphysiology association behaviorphysiology deglutition factors feeding file-import-08-07-30 food govt learning learningphysiology lipphysiology memory mouthphysiology non-us paired-associate physical psychology reinforcement stimulation support taste time http://www.citeulike.org/user/brembs/article/3063020 <i>Behav Neural Biol, Vol. 39, No. 1. (1983), 1-6.</i><br /><br />Aplysia fasciata attempt to bite and swallow food wrapped in a plastic net, tasting food through holes in the net. Net-enclosed food cannot be swallowed, and becomes cyclically lodged and pushed out of the buccal cavity. Aplysia gradually modify their response to this food, and eventually cease to respond. Twenty-four hours following training, memory is maintained, as shown by savings upon retraining. An essential component of the behavioral plasticity is food becoming stuck within the buccal cavity: when the lips are stimulated without allowing food to enter the buccal cavity, animals stop responding, but training takes longer, and memory is not retained. Savings upon retraining are contingent upon temporal pairing of food upon the lips and stimuli from within the buccal cavity: when lip stimuli and the experience of food stuck within the buccal cavity occur sequentially (rather than simultaneously), 24 hr later, animals are not significantly different from naive subjects. A learned change of response to inedible food in Aplysia AJ Susswein M Schwarz Behav Neural Biol, Vol. 39, No. 1. (1983), 1-6. 2008-07-30T12:57:46-00:00 1983 Behav Neural Biol 39 1 1-6 animal aplysia behavior conditioning feeding file-import-08-07-30 govt non-phs operant support taste us http://www.citeulike.org/user/brembs/article/3062900 <i>Behav Neurosci, Vol. 106, No. 2. (1992), 250-61.</i><br /><br />The absence of a conspecific, but not of food, interfered with learning and memory of a feeding task in Aplysia fasciata. Interference was shown by a shortened training session and by lack of savings on retraining. The shortened training is not responsible for the lack of savings because brief training in the presence of a conspecific led to savings on retraining. Animals trained in the absence of a conspecific and then tested in its presence did not show signs of having learned, which indicates that the absence of a conspecific interfered with the ability to learn, rather than with the expression of memory. Absence of a conspecific also inhibited other aspects of feeding behavior, such as the latency to respond to food and the length of time that animals respond to food, which indicate that interference with learning was apparently caused by inhibition of feeding behavior, rather than by block of the mechanisms underlying learning. Presence of conspecifics facilitates learning that food is inedible in Aplysia fasciata M Schwarz AJ Susswein Behav Neurosci, Vol. 106, No. 2. (1992), 250-61. 2008-07-30T12:57:34-00:00 1992 Behav Neurosci 106 2 250-61 activity animal aplysia appetitive association avoidance behavior environment feeding file-import-08-07-30 govt learning motivation motor non-phs non-us psychology recall retention social support us http://www.citeulike.org/user/brembs/article/3062899 <i>J Neurosci, Vol. 6, No. 5. (1986), 1528-36.</i><br /><br />Bilateral sectioning of the esophageal nerves that innervate the gut of Aplysia was found to have profound effect on response decrement to inedible food: Time to criterion for cessation of feeding was elevated, no memory of the decrement was present 24 hr after training, and motor patterning during training was altered. The parametric features of response decrement to sustained lip stimulation were examined to determine their resemblance to parameters of response decrement to inedible food after esophageal nerve sectioning. Parameters of response decrement were similar, indicating that after esophageal nerve sectioning response decrement is likely to be the result of sustained lip stimulation. Bilateral nerve sectioning had no effect on decrement due to sustained lip stimulation. Unilateral lesions and lesions of either of the two major divisions of the esophageal nerves had no effect on learning that food was inedible. The data indicate that bilateral nerve sectioning eliminates all stimuli causing negative reinforcement of feeding due to failure to consume food. Based on the data in this and the previous paper, a model is presented suggesting sites of action and mechanisms for learning that foods are edible or inedible in Aplysia. Identification of the neural pathway for reinforcement of feeding when Aplysia learn that food is inedible M Schwarz AJ Susswein J Neurosci, Vol. 6, No. 5. (1986), 1528-36. 2008-07-30T12:57:34-00:00 1986 J Neurosci 6 5 1528-36 animal aplysiaphysiology behaviorphysiology denervation esophagusinnervation factors feeding file-import-08-07-30 food govt histology learning lipphysiology memory nervous neural neuronal non-us pathwaysphysiology physical plasticity psychology reinforcement stimulation support systemanatomy time http://www.citeulike.org/user/brembs/article/3062898 <i>Brain Res, Vol. 294, No. 2. (1984), 363-6.</i><br /><br />Aplysia can be taught to stop responding to inedible food, by pairing lip stimuli with stimuli arising from food stuck in the buccal cavity. When the esophageal nerves innervating the gut are cut. Aplysia cease responding to inedible food in a mean of 2.09 times longer than when these nerves are intact. Patterning of feeding movements is also changed. Cessation of responses in lesioned animals may be due to adaptation caused by lip stimulation. The data suggest that the esophageal nerves carry information about whether food is edible or inedible. A neural pathway for learning that food is inedible in Aplysia M Schwarz AJ Susswein Brain Res, Vol. 294, No. 2. (1984), 363-6. 2008-07-30T12:57:34-00:00 1984 Brain Res 294 2 363-6 animal aplysiaphysiology esophagusinnervation file-import-08-07-30 food govt learning nerves neuronsphysiology non-phs peripheral preferences support us http://www.citeulike.org/user/brembs/article/3062897 <i>Behav Neurosci, Vol. 102, No. 1. (1988), 124-33.</i><br /><br />In order to determine whether different classes of behavioral plasticity affect common or unique neural loci, the effects of three types of processes that inhibit feeding in Aplysia were quantified. Changes in feeding behavior due to an associative learning task in which animals learn that food is inedible were compared with behavioral effects caused by satiation and by sustained lip stimulation. The data indicate that each process modifying feeding can be characterized by differences in time to stop responding to food, by differences in specificity of the decrement to a particular food, and by different patterns of motor output before complete cessation of responsiveness. The data suggest each process inhibiting feeding acts at a different neural site. Learning that food is inedible may be due to facilitation of a specific sensory pathway onto pattern generators producing rejection responses. Sustained lip stimulation seems to inhibit feeding by causing a decrement in all outputs of a particular sensory pathway. Finally, satiation appears to represent inhibition of feeding motor elements. Parametric features of inhibition of feeding in Aplysia by associative learning, satiation, and sustained lip stimulation M Schwarz S Markovich AJ Susswein Behav Neurosci, Vol. 102, No. 1. (1988), 124-33. 2008-07-30T12:57:34-00:00 1988 Behav Neurosci 102 1 124-33 animal aplysiaphysiology association behavior comparative feeding file-import-08-07-30 govt learning lip models non-phs non-us physical psychological satiation stimulation study support us http://www.citeulike.org/user/brembs/article/3062896 <i>Behav Neurosci, Vol. 105, No. 1. (1991), 193-201.</i><br /><br />Long-term memory of learning that a food is inedible was studied in Aplysia. Seven days after a single training session, animals retained significant memory, as measured by a number of parameters. A 2nd experiment demonstrated savings 3 weeks after 2 training sessions. Long-term memory was also found after training procedures were altered to resemble those more likely to occur in nature, such as training for only 10 min or training with ad-lib access to inedible food, with no experimenter intervention. The effects were determined of bilaterally sectioning the esophageal nerves that innervate the gut. Denervation of the gut blocked the ability to learn that food is inedible but did not affect memory after the task had already been learned. Variables affecting long-term memory of learning that a food is inedible in Aplysia M Schwarz E Feldman AJ Susswein Behav Neurosci, Vol. 105, No. 1. (1991), 193-201. 2008-07-30T12:57:34-00:00 1991 Behav Neurosci 105 1 193-201 activityphysiology animal aplysiaphysiology appetitive arousalphysiology avoidance behaviorphysiology classicalphysiology conditioning esophagusinnervation feeding file-import-08-07-30 govt learningphysiology motivation motor neuronal neuronsphysiology non-phs non-us plasticityphysiology psychologyphysiology recallphysiology retention support us http://www.citeulike.org/user/brembs/article/3062895 <i>Behav Neurosci, Vol. 112, No. 4. (1998), 942-51.</i><br /><br />Isolating a sexually mature Aplysia fasciata for either 1 or 24 hr immediately after training that a food is inedible blocks the subsequent expression of memory measured 24 hr later. Isolation that is delayed for 1 hr after training, but not for 12 hr after training, is also effective in blocking memory. Isolation affects memory because of a specific effect caused by the absence of pheromones secreted by conspecifics rather than by a nonspecific change in the chemical environment, because transferring animals to a novel environment (120% seawater) that contains a conspecific does not affect memory. Isolation also does not affect memory in sexually immature Aplysia, even though immature animals are able to sense one another's presence. Isolation may affect memory because social (and sexual) isolation is a form of stress in mature A. fasciata, and stress after training affects retention in many animals. Social isolation blocks the expression of memory after training that a food is inedible in Aplysia fasciata M Schwarz S Blumberg AJ Susswein Behav Neurosci, Vol. 112, No. 4. (1998), 942-51. 2008-07-30T12:57:34-00:00 1998 Behav Neurosci 112 4 942-51 age analysis animal aplysiaphysiology behaviorphysiology discrimination eatingphysiology factors feeding file-import-08-07-30 food govt isolationpsychology learningphysiology maturationphysiology memoryphysiology method non-us of pheromonesphysiology psychologicalphysiopathology sex single-blind social stress support time variance http://www.citeulike.org/user/brembs/article/3062656 <i>Genetics, Vol. 126, No. 1. (1990), 91-104.</i><br /><br />The Drosophila gene optomotor-blind (omb) is involved in the development of a set of giant neurons in the optic lobes and possibly other structures in the imaginal brain. Adult flies have discrete defects in optomotor behavior. The gene has previously been mapped in chromomeres 4C5-6, together with three other genes, bifid, Quadroon and lacqueredgls. We have localized the gene in a genomic walk of 340 kb of DNA. By mapping seven chromsome breakpoints with omb phenotype we determined its minimum size to about 80 kb. From this region more than 20 RNAs of different size and temporal expression pattern are transcribed. Three of them (T3, T7 and T7') stem from primary transcripts of 40-80 kb in length. In its distal part the omb gene overlaps in at least 19 kb with four other complementation units, bifid, l(1)bifid, Quadroon and lacqueredgls. The three nonlethals affect the external appearance of the fly and seem to be unrelated to brain development. Genetic and molecular characterization of the optomotor-blind gene locus in Drosophila melanogaster GO Pflugfelder H Schwarz H Roth B Poeck A Sigl S Kerscher B Jonschker WL Pak M Heisenberg Genetics, Vol. 126, No. 1. (1990), 91-104. 2008-07-30T12:56:58-00:00 1990 Genetics 126 1 91-104 file-import-08-07-30 http://www.citeulike.org/user/brembs/article/3062655 <i>Proc Natl Acad Sci U S A. (1992), 1199-203.</i> The lethal(1)optomotor-blind gene of Drosophila is a major organizer of optic lobe development: isolation and characterization of the gene. GO Pflugfelder H Roth B Poeck S Kerscher H Schwarz B Jonschker M Heisenberg Proc Natl Acad Sci U S A. (1992), 1199-203. 2008-07-30T12:56:58-00:00 1992 Proc Natl Acad Sci U S A. 1199-203 aminoacidsequence dna drosophila file-import-08-07-30 geneexpression lethalgenes mrna opticlobeembryology restrictionmapping structuralgenes transcription transcriptionfactors http://www.citeulike.org/user/brembs/article/2307582 <i>Current Biology, Vol. 18, No. 2. (22 January 2008), pp. R60-R62.</i><br /><br />Summary Numerical and spatial cognition rely on common functional circuits in the parietal lobes of the brain [1]. While previous work has established that the mere perception of numbers can bias a subject's attention in space [2], the method of random digit generation has only recently been introduced to a rapidly growing literature exploring asymmetries in number space [3]. Here we show that human subjects' attempts to generate numbers `at random' are systematically influenced by lateral head turns, which are known to reallocate spatial attention in the outside world. Specifically, while facing left, subjects produced relatively small numbers, whereas while facing right they tended to produce larger numbers. These results support current concepts of parietal cortex as mediating the interplay between spatial attention and abstract thought [4]. Head turns bias the brain's internal random generator Tobias Loetscher Urs Schwarz Michele Schubiger Peter Brugger doi:10.1016/j.cub.2007.11.015 Current Biology, Vol. 18, No. 2. (22 January 2008), pp. R60-R62. 2008-01-30T14:47:28-00:00 2008 Current Biology 18 2 R60 R62 numbers random spontaneous