nelson zabala - Academia.edu (original) (raw)
Papers by nelson zabala
Pharmacology Biochemistry and Behavior, 1984
1984.-A praying mantis displays a "frightening reaction" called deimatic reaction (DR), any time ... more 1984.-A praying mantis displays a "frightening reaction" called deimatic reaction (DR), any time that it is faced with a patterned visual stimulus that represents a potential damage for the insect. Results of the present paper show that the DR could be also elicited by an actual noxious (an electrical shock) and that this response is similar to that elicited by a potential nociceptive stimulus (a patterned visual stimulus). The DR elicited by the electric shock was used as a model for
Acta científica venezolana, 1987
Pharmacology Biochemistry and Behavior, 1990
The involvement of certain amino acids in the memory consolidation process was investigatext in t... more The involvement of certain amino acids in the memory consolidation process was investigatext in the cricket Pteronemobius sp. Thirsty crickets were trained to constantly torn to one side of a symmetrical Y-shaped maze using reinforcement with water. Controls were trained to turn to both sides of the maze according to a random program. Animals were sacrificed immediately after training and free amino acid fractions were isolated from whole brain, subesophagic, prothoracic, mesothoracic and metathoracic ganglia homogenates and analyzed by high pressure liquid chromatography. A complex pattern of variation in the titer of amino acids emerged after learning, where the changes differed among the various ganglia. The most conspicuous change was an increase in the levels of urea and an amino acid-like compound related to the urea cycle, in all ganglia except the subesophagic one, if compared to controls. Arginine increased in the subesophagic ganglion, but decreased significantly in the metathoracic ganglion. The variation of ganglionic amino acid levels and its possible relation to mnemonic processes is discussed.
Pharmacology Biochemistry and Behavior, 1992
We followed the titer of free amino acids in nervous ganglia and hemolimph of the cricket Pterone... more We followed the titer of free amino acids in nervous ganglia and hemolimph of the cricket Pteronemobius sp. at different times during and after a shock avoidance training that included one experimental group and three controls. The results showed that Tau, urea, Thr, His, GABA, and an unidentified compound (Q) increased their titer in ganglia and hemolimph during training, whereas Ala, Arg, Val, Glu, Ser, and one or all of the group formed by Cys, Phe, Ile, Leu, and Trp decreased theirs concomitantly to memory consolidation. The difference in the rate of experimental insects and their yoked slaves to consolidate the learned task was reflected in the changes of the titers of the amino acids mentioned above. The data add to the evidence for a direct involvement of these amino acids in modulating the memory consolidation process. Amino acids Insects Memory consolidation Long-term memory Memory Crickets Neuromodulation Aversive conditioning Learning Amino acid changes
Journal of comparative physiology, 1982
... of variance shows that estimated variance between means is due to chance (F=0.18), ie neither... more ... of variance shows that estimated variance between means is due to chance (F=0.18), ie neither the type of amino acid in the solution nor the fact ... This is in line with the results of Maldo-nado (1980), who showed that the increase in density at position +2 was correlated with an ...
Experientia, 1984
... 2 McCrea, F, D., Eadie, GS, and Morgan, JE, J. Pharmac. ... Recently it has been shown that m... more ... 2 McCrea, F, D., Eadie, GS, and Morgan, JE, J. Pharmac. ... Recently it has been shown that morphine has an antinoxious action in 2 arthropods: the mantis shrimp 2 and the honey bee 3. Morphine increases the threshold for behavioral responses to electric shocks, ie the violent ...
Pharmacology Biochemistry and Behavior, 1991
The escape reaction time (ERT) of the cricket Pteronemobius sp. from the heated box begins at 48 ... more The escape reaction time (ERT) of the cricket Pteronemobius sp. from the heated box begins at 48 ° and increases with temperature until 56°C, beyond which there is no further increase. The ERT (2.2-~ 1.39 s) from the hot box at 54°C is used as a model for studying the analgesic effects of opiates. Results of the present paper show that the ERT did not change after injecting the insect in the abdominal haemocoel with 0.9% saline solution, but ERT increased when 0.32, 0.52 or 0.69 mg/g of morphine is injected in the same place. The maximum ERT increase is reached at 90 rain after drug injection, and the drug effect disappears 3 h after the injection. At 90 rnin after drug injections, the dose of 0.50 mg/g of morphine produces 50% of ERT increase, and it is referred to as the median analgesic dose (Dso). 1.05 mg/g of morphine produces an ERT longer than 30 s that results in an irreversible damage to the insect. Sixty-four Izg/g of naloxone given in addition to Dso of morphine fully blocked the effect of morphine during its 3-h action. However, more than 64 Izg/g of naloxone alone also increase the ERT in the cricket, similar to what has been described for vertebrates. Four daily morphine injections of Dso decreased ERT in such a way that, at the fourth day, the ERT is similar to the ERT produced by saline solution; i.e., tolerance is shown. The suppression of daily morphine injections of D~o during the fifth day produced a hyperresponse to vibration (big jumps) not shown in the case of the injections of saline solution; i.e., addiction is shown.
Acta Cientifica Venezolana, Feb 1, 1990
Learning and memory consolidation was investigated in the mantis Stagmatoptera biocellata, by two... more Learning and memory consolidation was investigated in the mantis Stagmatoptera biocellata, by two successive trainings: a) the attack (A) avoidance training in which animals were not allowed to catch a mobile star, followed by the deimatic reaction (DR) avoidance training of not displaying this defensive response, or b) DR-avoidance training followed by A-avoidance training. The results showed that the presence and the 1 of A-avoidance learning and DR-avoidance learning did not affect the learning of the other training. Total retention of A-avoidance memory was demonstrated when A-avoidance training was given first, whereas DR-avoidance memory was significantly lost (716%) when the DR-avoidance training was given first. The retroactive forgetting of DR-avoidance memory is considered as retrograde amnesia rather than retroactive memory inhibition because it depends on the activity during A-avoidance training (number of attacks) and not the quantity of A-avoidance learning. The magnitude of the amnesic effect due to this distracting activity in the A-avoidance training appears to be remarkably similar to that reported in a previous work using nitrogen-induced anoxia as the amnesic factor.
Pharmacology Biochemistry and Behavior, 1984
1984.-A praying mantis displays a "frightening reaction" called deimatic reaction (DR), any time ... more 1984.-A praying mantis displays a "frightening reaction" called deimatic reaction (DR), any time that it is faced with a patterned visual stimulus that represents a potential damage for the insect. Results of the present paper show that the DR could be also elicited by an actual noxious (an electrical shock) and that this response is similar to that elicited by a potential nociceptive stimulus (a patterned visual stimulus). The DR elicited by the electric shock was used as a model for
Acta científica venezolana, 1987
Pharmacology Biochemistry and Behavior, 1990
The involvement of certain amino acids in the memory consolidation process was investigatext in t... more The involvement of certain amino acids in the memory consolidation process was investigatext in the cricket Pteronemobius sp. Thirsty crickets were trained to constantly torn to one side of a symmetrical Y-shaped maze using reinforcement with water. Controls were trained to turn to both sides of the maze according to a random program. Animals were sacrificed immediately after training and free amino acid fractions were isolated from whole brain, subesophagic, prothoracic, mesothoracic and metathoracic ganglia homogenates and analyzed by high pressure liquid chromatography. A complex pattern of variation in the titer of amino acids emerged after learning, where the changes differed among the various ganglia. The most conspicuous change was an increase in the levels of urea and an amino acid-like compound related to the urea cycle, in all ganglia except the subesophagic one, if compared to controls. Arginine increased in the subesophagic ganglion, but decreased significantly in the metathoracic ganglion. The variation of ganglionic amino acid levels and its possible relation to mnemonic processes is discussed.
Pharmacology Biochemistry and Behavior, 1992
We followed the titer of free amino acids in nervous ganglia and hemolimph of the cricket Pterone... more We followed the titer of free amino acids in nervous ganglia and hemolimph of the cricket Pteronemobius sp. at different times during and after a shock avoidance training that included one experimental group and three controls. The results showed that Tau, urea, Thr, His, GABA, and an unidentified compound (Q) increased their titer in ganglia and hemolimph during training, whereas Ala, Arg, Val, Glu, Ser, and one or all of the group formed by Cys, Phe, Ile, Leu, and Trp decreased theirs concomitantly to memory consolidation. The difference in the rate of experimental insects and their yoked slaves to consolidate the learned task was reflected in the changes of the titers of the amino acids mentioned above. The data add to the evidence for a direct involvement of these amino acids in modulating the memory consolidation process. Amino acids Insects Memory consolidation Long-term memory Memory Crickets Neuromodulation Aversive conditioning Learning Amino acid changes
Journal of comparative physiology, 1982
... of variance shows that estimated variance between means is due to chance (F=0.18), ie neither... more ... of variance shows that estimated variance between means is due to chance (F=0.18), ie neither the type of amino acid in the solution nor the fact ... This is in line with the results of Maldo-nado (1980), who showed that the increase in density at position +2 was correlated with an ...
Experientia, 1984
... 2 McCrea, F, D., Eadie, GS, and Morgan, JE, J. Pharmac. ... Recently it has been shown that m... more ... 2 McCrea, F, D., Eadie, GS, and Morgan, JE, J. Pharmac. ... Recently it has been shown that morphine has an antinoxious action in 2 arthropods: the mantis shrimp 2 and the honey bee 3. Morphine increases the threshold for behavioral responses to electric shocks, ie the violent ...
Pharmacology Biochemistry and Behavior, 1991
The escape reaction time (ERT) of the cricket Pteronemobius sp. from the heated box begins at 48 ... more The escape reaction time (ERT) of the cricket Pteronemobius sp. from the heated box begins at 48 ° and increases with temperature until 56°C, beyond which there is no further increase. The ERT (2.2-~ 1.39 s) from the hot box at 54°C is used as a model for studying the analgesic effects of opiates. Results of the present paper show that the ERT did not change after injecting the insect in the abdominal haemocoel with 0.9% saline solution, but ERT increased when 0.32, 0.52 or 0.69 mg/g of morphine is injected in the same place. The maximum ERT increase is reached at 90 rain after drug injection, and the drug effect disappears 3 h after the injection. At 90 rnin after drug injections, the dose of 0.50 mg/g of morphine produces 50% of ERT increase, and it is referred to as the median analgesic dose (Dso). 1.05 mg/g of morphine produces an ERT longer than 30 s that results in an irreversible damage to the insect. Sixty-four Izg/g of naloxone given in addition to Dso of morphine fully blocked the effect of morphine during its 3-h action. However, more than 64 Izg/g of naloxone alone also increase the ERT in the cricket, similar to what has been described for vertebrates. Four daily morphine injections of Dso decreased ERT in such a way that, at the fourth day, the ERT is similar to the ERT produced by saline solution; i.e., tolerance is shown. The suppression of daily morphine injections of D~o during the fifth day produced a hyperresponse to vibration (big jumps) not shown in the case of the injections of saline solution; i.e., addiction is shown.
Acta Cientifica Venezolana, Feb 1, 1990
Learning and memory consolidation was investigated in the mantis Stagmatoptera biocellata, by two... more Learning and memory consolidation was investigated in the mantis Stagmatoptera biocellata, by two successive trainings: a) the attack (A) avoidance training in which animals were not allowed to catch a mobile star, followed by the deimatic reaction (DR) avoidance training of not displaying this defensive response, or b) DR-avoidance training followed by A-avoidance training. The results showed that the presence and the 1 of A-avoidance learning and DR-avoidance learning did not affect the learning of the other training. Total retention of A-avoidance memory was demonstrated when A-avoidance training was given first, whereas DR-avoidance memory was significantly lost (716%) when the DR-avoidance training was given first. The retroactive forgetting of DR-avoidance memory is considered as retrograde amnesia rather than retroactive memory inhibition because it depends on the activity during A-avoidance training (number of attacks) and not the quantity of A-avoidance learning. The magnitude of the amnesic effect due to this distracting activity in the A-avoidance training appears to be remarkably similar to that reported in a previous work using nitrogen-induced anoxia as the amnesic factor.