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851.
NMDA and muscarinic receptors of the nucleus accumbens have differential effects on taste memory formation
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Ramírez-Lugo L Zavala-Vega S Bermúdez-Rattoni F 《Learning & memory (Cold Spring Harbor, N.Y.)》2006,13(1):45-51
Animals recognize a taste cue as aversive when it has been associated with post-ingestive malaise; this associative learning is known as conditioned taste aversion (CTA). When an animal consumes a new taste and no negative consequences follow, it becomes recognized as a safe signal, leading to an increase in its consumption in subsequent presentations (attenuation of neophobia, AN). It has been shown that the nucleus accumbens (NAcc) has an important role in taste learning. To elucidate the involvement of N-methyl-D-aspartate (NMDA) and muscarinic receptors in the NAcc during safe and aversive taste memory formation, we administrated bilateral infusions of DL-2-amino-5-phosphonopentanoic acid (APV) or scopolamine in the NAcc shell or core respectively. Our results showed that pre-training injections of APV in the NAcc core and shell disrupted aversive but not safe taste memory formation, whereas pre-training injections of scopolamine in the NAcc shell, but not core, disrupted both CTA and AN. These results suggest that muscarinic receptors seem to be necessary for processing taste stimuli for either safe or aversive taste memory, whereas NMDA receptors are only involved in the aversive taste memory trace formation. 相似文献
852.
Previous studies on visual working memory (VWM) have primarily investigated memory for an array presented for a single moment.
Here, we examined VWM for two arrays separated by a 1,100-msec interval. We focused on the allocation of VWM capacity to the
two arrays as a function of dynamic events inserted between them. During the interval, irrelevant dots moved to form three
types of motion: (1) coherent (apparent) motion that connected Arrays 1 and 2, (2) jumpy motion, or (3) coherent motion with
two disconnected segments. Results showed that VWM for Array 2’s locations was better than for Array 1’s, especially when
the arrays were connected by coherent motion. We suggest that coherent motion between two temporally disparate arrays connects
the arrays into a single visual event VWM is then biased toward remembering the more recent state of the event. 相似文献
853.
Vidal-Gonzalez I Vidal-Gonzalez B Rauch SL Quirk GJ 《Learning & memory (Cold Spring Harbor, N.Y.)》2006,13(6):728-733
Recent studies using lesion, infusion, and unit-recording techniques suggest that the infralimbic (IL) subregion of medial prefrontal cortex (mPFC) is necessary for the inhibition of conditioned fear following extinction. Brief microstimulation of IL paired with conditioned tones, designed to mimic neuronal tone responses, reduces the expression of conditioned fear to the tone. In the present study we used microstimulation to investigate the role of additional mPFC subregions: the prelimbic (PL), dorsal anterior cingulate (ACd), and medial precentral (PrCm) cortices in the expression and extinction of conditioned fear. These are tone-responsive areas that have been implicated in both acquisition and extinction of conditioned fear. In contrast to IL, microstimulation of PL increased the expression of conditioned fear and prevented extinction. Microstimulation of ACd and PrCm had no effect. Under low-footshock conditions (to avoid ceiling levels of freezing), microstimulation of PL and IL had opposite effects, respectively increasing and decreasing freezing to the conditioned tone. We suggest that PL excites amygdala output and IL inhibits amygdala output, providing a mechanism for bidirectional modulation of fear expression. 相似文献
854.
Agin V Poirier R Chichery R Dickel L Chichery MP 《Neurobiology of learning and memory》2006,86(3):264-269
The inhibition of predatory behavior observed during the "prawn-in-the-tube" procedure has been extensively used in studies of cuttlefish learning. The present study examines the effect of age on the conditioning of this response in the cuttlefish, Sepia officinalis. Data show that a significant increase in acquisition performance occurs between 15 and 21 days of age. The retention curves in 8- and 15-day-old cuttlefish show a monotonic memory process, presumably reflecting the presence of only short-term memory. In 21-day-old cuttlefish, there are two distinct processes which could be a labile short-term memory, and a subsequent intermediate memory. These mnesic systems seem to become more effective over the course of post-embryonic development. Moreover, the retention curves obtained in the oldest cuttlefish (30- and 90-day-old) bear a close resemblance to that observed in adults. These behavioral findings will allow further work on the cellular and molecular mechanisms of learning and memory in the cuttlefish. 相似文献
855.
Prado-Alcalá RA Díaz del Guante MA Garín-Aguilar ME Díaz-Trujillo A Quirarte GL McGaugh JL 《Neurobiology of learning and memory》2006,86(2):144-149
The hypothesis that memory is stored through a single stage of consolidation that results in a stable and lasting long-term memory has been challenged by the proposition that reactivation of a memory induces reconsolidation of the memory. The reconsolidation hypothesis is supported by evidence that, under some conditions, post-retrieval treatments affecting amygdala and hippocampus functioning impair subsequent retention performance. We now report that repeated retention testing attenuates the performance impairment induced by post-retrieval reversible inactivation of the amygdala and hippocampus of rats induced by tetrodotoxin. These findings challenge the reconsolidation hypothesis and suggest that the post-retrieval retention performance impairment is best explained as due to temporary retrieval failure. 相似文献
856.
Taste aversion learning (TAL) is a type of learning characterized by rejection of a gustatory/flavor stimulus as a consequence of its pairing with visceral discomfort and malaise. TAL can be established in the laboratory by two different behavioral procedures, concurrent or sequential. Neural mechanisms of these learning modalities remain to be elucidated, but several studies have discussed the implication of various anatomical structures, including the vagus nerve. The aim of this study was to examine the role of capsaicin-sensitive vagal afferent fibers in concurrent (Experiment 1) and sequential (Experiment 2) TAL in Wistar rats. Results showed that perivagal administration of capsaicin (1mg of capsaicin dissolved in 1ml of vehicle (10% Tween 80 in oil)) blocked acquisition of concurrent but not sequential TAL. These data support the hypothesis of two different modalities of TAL mediated by distinct neurobiological systems, with vagal nerve participation only being essential in concurrent TAL. 相似文献
857.
da Silva WC Bonini JS Bevilaqua LR Izquierdo I Cammarota M 《Neurobiology of learning and memory》2006,86(1):100-106
Several evidences suggest that brain histamine is involved in memory consolidation but the actual contribution of the hippocampal histaminergic system to this process remains controversial. Here, we show that when infused into the CA1 region of the dorsal hippocampus immediately after training in an inhibitory avoidance task, but not later, histamine induced a dose-dependent promnesic effect without altering locomotor activity, exploratory behavior, anxiety state or retrieval of the avoidance response. The facilitatory effect of intra-CA1 histamine was mimicked by the histamine N-methyltransferase inhibitor SKF-91844 as well as by the H2 receptor agonist dimaprit and it was blocked completely by the H2 receptor antagonist ranitidine. Conversely, the promnesic action of histamine was unaffected by the H1 receptor antagonist pyrilamine, the H3 receptor antagonist, thioperamide, and the NMDAr polyamine-binding site antagonist ifenprodil. By themselves, ranitidine, pyrilamine, thioperamide, and ifenprodil did not affect IA memory consolidation. Our data indicate that, when given into CA1, histamine enhances memory consolidation through a mechanism that involves activation of H2 receptors; however, endogenous CA1 histamine does not seem to participate in the consolidation of IA memory at least at the post-training times analyzed. 相似文献
858.
Ashmarin IP Danilova RA Rud'ko OI Belopolskaya MV Obukhova MF Shmalgausen EV 《The Spanish journal of psychology》2006,9(2):219-227
The inhibitor of monoaminooxydase isatin and the ligand of B-receptors cholecystokinin-4 play a significant role in the suppression and induction of depressive and anxiety states. We induced the formation of auto-antibodies to these compounds against their conjugates with antigen-carrier by immunization of white rats. The result was long-term (more than 2 months) stimulation of depressive and anxiety behavior after immunization to isatin and, in contrast, the suppression of such behavior after immunization to cholecystokinin. The perspective of immunochemical approach to long-term correction of behavior is discussed. 相似文献
859.
Lonsdorf EV 《Animal cognition》2006,9(1):36-46
This paper explores the role of maternal influences on the acquisition of a tool-using task in wild chimpanzees (Pan troglodytes schweinfurthii) in order to build on and complement previous work done in captivity. Young chimpanzees show a long period of offspring dependency
on mothers and it is during this period that offspring learn several important skills, especially how to and on what to forage.
At Gombe National Park, one skill that is acquired during dependency is termite-fishing, a complex behavior that involves
inserting a tool made from the surrounding vegetation into a termite mound and extracting the termites that attack and cling
to the tool. All chimpanzees observed at Gombe have acquired the termite-fishing skill by the age of 5.5 years. Since the
mother is the primary source of information throughout this time period, I investigated the influence of mothers' individual
termite-fishing characteristics on their offsprings' speed of acquisition and proficiency at the skill once acquired. Mother's
time spent alone or with maternal family members, which is highly correlated to time spent termite-fishing, was positively
correlated to offspring's acquisition of critical elements of the skill. I also investigated the specific types of social
interactions that occur between mothers and offspring at the termite mound and found that mothers are highly tolerant to offspring,
even when the behavior of the offspring may disrupt the termite-fishing attempt. However, no active facilitation by mothers
of offsprings' attempts were observed.
Electronic Supplementary Material Electronic supplementary material Supplementary material is available for this article at http://dx.doi.org/10.1007/s10071-005-0002-7
and accessible for authorised users. 相似文献
860.
This research demonstrates that preference for emotions sometimes cannot be equated with a positive-negative valence dimension. Participants were asked to make choices between pairs of affect-inducing options opposite in valence but equal in activation. The results showed that in absence of contextual cues or situational constraints, choices followed a pleasure-maximizing principle. However, when information was provided about a context cueing appropriateness of certain emotions over others, a preference reversal was observed so that negative emotions were preferred over positive emotions. These results are discussed in relation to current theories of pleasure-maximizing choice and behavior. 相似文献