RESUMO
Taste memory depends on motivational and post-ingestional consequences after a single taste-illness pairing. During conditioned taste aversion (CTA), the taste and visceral pathways reach the nucleus of the solitary tract (NTS), which is the first relay in the CNS and has a vital function in receiving vagal chemical stimuli and humoral signals from the area postrema that receives peripheral inputs also via vagal afferent fibers. The specific aim of the present set of experiments was to determine if the NTS is involved in the noradrenergic and glutamatergic activation of the basolateral amygdala (BLA) during CTA. Using in vivo microdialysis, we examined whether chemical NTS stimulation induces norepinephrine (NE) and/or glutamate changes in the BLA during visceral stimulation with intraperitoneal (i.p.) injections of low (0.08 M) and high (0.3 M) concentrations of lithium chloride (LiCl) during CTA training. The results showed that strength of CTA can be elicited by chemical NTS stimulation (Ringer's high potassium solution; 110 mM KCl) and by intra-NTS microinjections of glutamate, immediately after, but not before, low LiCl i.p. injections that only induce a week aversive memory. However visceral stimulation (with low or high i.p. LiCl) did not induce significantly more NE release in the amygdala compared with the NE increment induced by NTS potassium depolarization. In contrast, high i.p. concentrations of LiCl and chemical NTS stimulation induced a modest glutamate sustained release, that it is not observed with low LiCl i.p. injections. These results indicate that the NTS mainly mediates the visceral stimulus processing by sustained releasing glutamate in the BLA, but not by directly modulating NE release in the BLA during CTA acquisition, providing new evidence that the NTS has an important function in the transmission of signals from the periphery to brain systems that process aversive memory formation.
Assuntos
Complexo Nuclear Basolateral da Amígdala/efeitos dos fármacos , Complexo Nuclear Basolateral da Amígdala/metabolismo , Memória/efeitos dos fármacos , Núcleo Solitário/metabolismo , Paladar/efeitos dos fármacos , Animais , Condicionamento Clássico/efeitos dos fármacos , Ácido Glutâmico/metabolismo , Injeções Intraperitoneais , Cloreto de Lítio/administração & dosagem , Cloreto de Lítio/farmacologia , Masculino , Microdiálise , Norepinefrina/metabolismo , Ratos , Ratos Sprague-Dawley , Núcleo Solitário/efeitos dos fármacos , Estimulação QuímicaRESUMO
B. F. Skinner (1904-1990) é frequentemente citado como representante de um posicionamento contrário ao uso de controle aversivo. Entretanto, observa-se certa divergência, na literatura comportamental, quanto à postura de Skinner a esse respeito. O presente trabalho teve como objetivo identificar e analisar em quais momentos Skinner prescreve ou adverte sobre o uso do controle aversivo. Um estudo conceitual foi realizado, no qual oito obras (Skinner 1938/1991; 1948/1975; 1953/1989; 1968/1972; 1969/1980; 1971; 1974/2006; 1989) foram analisadas conforme as categorias: 1) a definição de controle aversivo e conceitos envolvidos; 2) os aspectos negativos do controle aversivo e proibições; e 3) os aspectos positivos do controle aversivo e prescrições. Por fim, não foi possível encontrar uma definição específica de controle aversivo, e constatou-se que em determinados momentos Skinner justifica o uso deste tipo de controle, mas não o prescreve genericamente.(AU)
B. F. Skinner (1904-1990) is frequently cited as having a contrary position on the use of aversive control. However, in certain passages Skinner presents a more flexible opinion about the use of this type of behavioral control. The purpose of the present study was to identify and analyze the passages where Skinner prescribes or warns about such use. A conceptual study was conducted involving eight Skinner works (Skinner 1938/1991, 1948/1975, 1953/1989, 1968/1972, 1969/1980, 1971, 1974/2006, 1989), analyzed according to the following categories: 1) the definition of aversive control and concepts involved; 2) the negative aspects of aversive control and prohibitions; and 3) the positive aspects of aversive control and its recommendations. It wasn't possible to find a specific definition of aversive control and it was observed that at certain moments Skinner justifies the use of aversive control, but does not prescribe it in general.(AU)
Assuntos
Humanos , Comportamento , Controle Comportamental/métodos , Reforço PsicológicoRESUMO
B. F. Skinner (1904-1990) é frequentemente citado como representante de um posicionamento contrário ao uso de controle aversivo. Entretanto, observa-se certa divergência, na literatura comportamental, quanto à postura de Skinner a esse respeito. O presente trabalho teve como objetivo identificar e analisar em quais momentos Skinner prescreve ou adverte sobre o uso do controle aversivo. Um estudo conceitual foi realizado, no qual oito obras (Skinner 1938/1991; 1948/1975; 1953/1989; 1968/1972; 1969/1980; 1971; 1974/2006; 1989) foram analisadas conforme as categorias: 1) a definição de controle aversivo e conceitos envolvidos; 2) os aspectos negativos do controle aversivo e proibições; e 3) os aspectos positivos do controle aversivo e prescrições. Por fim, não foi possível encontrar uma definição específica de controle aversivo, e constatou-se que em determinados momentos Skinner justifica o uso deste tipo de controle, mas não o prescreve genericamente.
B. F. Skinner (1904-1990) is frequently cited as having a contrary position on the use of aversive control. However, in certain passages Skinner presents a more flexible opinion about the use of this type of behavioral control. The purpose of the present study was to identify and analyze the passages where Skinner prescribes or warns about such use. A conceptual study was conducted involving eight Skinner works (Skinner 1938/1991, 1948/1975, 1953/1989, 1968/1972, 1969/1980, 1971, 1974/2006, 1989), analyzed according to the following categories: 1) the definition of aversive control and concepts involved; 2) the negative aspects of aversive control and prohibitions; and 3) the positive aspects of aversive control and its recommendations. It wasn't possible to find a specific definition of aversive control and it was observed that at certain moments Skinner justifies the use of aversive control, but does not prescribe it in general.
Assuntos
Humanos , Comportamento , Controle Comportamental/métodos , Reforço PsicológicoRESUMO
The effect of an aversive stimulus represented by contact with a hot plate on the heart rate of Megalobulimus mogianensis was evaluated with electrocardiogram recording in intact snails (N = 8). All stimulated animals showed an increase in heart rate, with mean values ranging from 35.6 ± 1.2 (basal heart rate) to 43.8 ± 0.9 bpm (post-stimulation heart rate). The cardioacceleration was followed by gradual recovery of the basal heart rate, with mean recovery times varying from 4.3 ± 0.3 to 5.8 ± 0.6 min. Repetition of the stimulus did not affect the magnitude of variation nor did it influence the basal heart rate recovery time. To investigate the role of the cardiac nerve in mediating the heart rate alterations induced by the aversive stimulus, denervated (N = 8) and sham-operated (N = 8) animals were also tested. Although the aversive stimulus caused the heart rate to increase significantly in both experimental groups, the mean increase in heart rate in denervated animals (4.4 ± 0.4 bpm) was 57 percent of the value obtained in sham-operated animals (7.7 ± 1.3 bpm), indicating that the cardiac nerve is responsible for 43 percent of the cardioacceleration induced by the aversive stimulus. The cardioacceleration observed in denervated snails may be due to an increase in venous return promoted by the intense muscular activity associated with the withdrawal response. Humoral factors may also be involved. A probable delaying inhibitory effect of the cardiac nerve on the recuperation of the basal heart rate is suggested.