Latent inhibition experiments with goldfish (Carassius auratus).

Examined evidence of latent inhibition in a series of experiments with goldfish. In Exp I, 12 Ss were given nonreinforced preexposure to a color that subsequently predicted shock in an activity conditioning situation; their performance did not differ from that of 12 control Ss preexposed to a markedly different color. In Exp II, 12 Ss given nonreinforced preexposure to a tone and an unstimulated control group of 12 Ss were trained in an appetitive situation, with the tone serving either as a conditioned excitor or as a conditioned inhibitor. Preexposure had significant effect in the conditioned excitation training, but it reduced the level of responding both to the positive stimulus and to the negative compound in the conditioned inhibition training. In Exps III and IV, classical aversive conditioning was studied in the shuttle box. In Exp III, excitatory conditioning to a color was found to be impaired (relative to the performance of nonpreexposed control Ss) as much by nonreinforced preexposure to the training color as by nonreinforced preexposure to a markedly different color; substantial variation in amount of preexposure was without significant effect. In the conditioned inhibition training of Exp IV, 12 Ss with nonreinforced preexposure responded less than did 12 unstimulated control Ss, both to the positive stimulus and to the negative compound. Results demonstrate that the effect of preexposure on goldfish is their reduction of general responsiveness or level of arousal. (47 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Different ways of encoding geometric information by goldfish (Carassius auratus).

On the basis of results of a probe trial in 2 different experiments, K. Cheng (2005) has proposed a common mechanism for orientation in fish trained in both a maplike or relational procedure and a directly cued procedure. However, K. Cheng's model is inconsistent with previous results of goldfish (Carassius auratus) trained in these 2 tasks. Given that K. Cheng's proposal assumes that fish choose the goal by using a matching strategy in which they try to match as many properties as possible, including geometric and featural properties, future research is necessary to clarify what properties of the environmental space are codified and used for navigation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of telencephalic NMDA receptors in avoidance learning in goldfish (Carassius auratus).

Studies with goldfish (Carassius auratus) have suggested that N-methyl-D-aspartate (NMDA) receptors are concentrated most densely in the telencephalon, a simple structure homologous to the limbic stricture of higher vertebrates. The present study investigated the amnestic effects of microinjections of the NMDA receptor antagonist D(-)-2-amino-5-phosphonopentanoic acid (D-AP5) to the goldfish telencephalon on avoidance conditioning. Results showed that microinjections of D-AP5 before training impaired avoidance learning at doses that did not impair performance processes. High-performance liquid chromatography measurements showed that D-AP5 was detected only in the telencephalon following microinjections. Thus, D-AP5 impaired avoidance learning through its interaction with telencephalic NMDA receptors in goldfish. Furthermore, microinjections of D-AP5 to the goldfish telencephalon immediately following training did not impair memory consolidation of avoidance conditioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Serial ablations of the telencephalon and avoidance learning by goldfish (Carassius auratus).

Simultaneous bilateral ablation of the teleost telencephalon was confirmed to impair the retention, extinction, and reversal learning of a preoperatively learned instrumental avoidance response in a shuttle box. The focus of the experiment, using 30 goldfish, was on whether 2-stage serial unilateral ablations of the teleost telencephalon would ameliorate the effects seen following 1-stage bilateral ablation and whether such amelioration would be a function of S's experiences between the staged ablations. The degree of retention, relearning, and extinction of the avoidance response was not modulated by the serial ablation procedure whether or not there was interoperation retraining experience. However, reversal learning, in which the previous warning signal became the safety signal and the previous safety signal became the new warning signal, was less impaired following serial ablations than following single-stage bilateral ablation. Results are contrasted with those from experiments with mammalian Ss. (46 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of telencephalic NO and cGMP in avoidance conditioning in goldfish (Carassius auratus).

Our previous study with N-methyl-D-aspartate (NMDA) receptor antagonist D-AP5 suggested that NMDA receptors were involved in learning but not memory consolidation of avoidance conditioning. The present study investigated whether nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) were involved in memory consolidation but not learning of avoidance conditioning in goldfish. Experiments 1 to 3 investigated amnestic and performance effects of NO inhibitor L-NAME and cGMP inhibitor LY-83583. Experiment 4 investigated whether posttraining intratelencephalic injection of NO donor SNAP ameliorated anterograde amnestic effects of pretraining NO inhibitor L-NAME. The results showed that L-NAME and LY-83583 produced significant anterograde and retrograde amnesia at doses that did not impair performance processes, and the drugs produced more severe retrograde than anterograde amnesia. Furthermore, posttraining SNAP significantly ameliorated anterograde amnestic effects of pretraining L-NAME. Thus, our previous results with D-AP5 and current results with L-NAME and LY-83583 together suggest that the NMDA receptors are involved in learning or the process that is completed during training, whereas the NO and cGMP are involved in memory consolidation or the process that is normally completed sometime following the learning experience. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Performance of goldfish (Carassius auratus) in patterned sequences of rewarded and nonrewarded trials.

Studied the performance of 40 goldfish in 4 experiments with patterned sequences of reward (R) and nonreward (N) for responses to a given stimulus (S3). Trials with 2 other, readily discriminable stimuli, in which response to one was always rewarded and response to the 2nd never rewarded, were interpolated in such a way that the outcome of any S3 trial could not be predicted from the events of the immediately preceding trial. The main purpose was to look for control of response to S3 based on memory of N like that found in previous work with pigeons. In Exps I and II, blocks of R and N trials with S3 were programmed, R trials in the 1st half of each session and N in the last half, or N trials in the 1st half and R in the last half. In Exp III, successive acquisition and extinction of response to S3 was studied, with the N-to-R, and R-to-N transitions either within sessions or between sessions. In Exp IV, the effects of partial and consistent reinforcement on extinction of response to S3 were compared. Results are similar in important respects to those for pigeons, as described by P. A. Couvillon et al (see record 1981-07158-001), but different in their failure to demonstrate control of performance by memory of N. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The detection of pressure fluctuations, sonic audition, is the dominant mode of dipole-source detection in goldfish (Carassius auratus).

Behavioral detection of a low-frequency (40 Hz) vibratory dipole at source distances of 1.5–24 cm was measured by classically conditioned respiratory suppression in goldfish (Carassius auratus). Detection thresholds were compared across distances and before and after ablation of individual octavolateralis sensory channels. Detection thresholds, expressed in units of pressure (SPL), remained roughly constant as distance between the stimulus source and animal increased. Lateral line inactivation, using CoCl2, had no measurable effect on sensitivity, although some other results can be construed as weak evidence for a small contribution of the lateral line to dipole detection when source distances are ≤6 cm (     

Localization of telencephalic regions concerned with habituation of cardiac and ventilatory responses associated with arousal in the goldfish (Carassius auratus).

54 goldfish were presented with a light-on stimulus at 2-min intervals, and their cardiac and ventilatory responses were monitored. Normal Ss, Ss with sham operations for telencephalic lesions, and Ss with bilateral electrolytic lesions of the telencephalon (anterior commissural and posterior telencephalic groups) were compared for responsiveness and habituation to regularly presented stimuli. There was no evident difference in responsiveness between the 4 groups, although 3 Ss with lesions in the regions ventralis pars dorsalis and ventralis pars ventralis gave fright responses to novel stimuli. Lesions in posterior telencephalic regions dorsalis pars centralis and ventralis pars intermedialis and at the telencephalic/diencephalic border close to the habenula caused significant impairment of habituation. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perception of frequency, amplitude, and azimuth of a vibratory dipole source by the octavolateralis system of goldfish (Carassius auratus).

Goldfish (Carassius auratus) were conditioned to suppress respiration to a 40-Hz vibratory source and subsequently tested for stimulus generalization to frequency, stimulus amplitude, and position (azimuth). Animals completely failed to generalize to frequencies separated by octave intervals both lesser and greater than the CS. However, they did appear to generalize weakly to an aerial loudspeaker stimulus of the same frequency (40 Hz) after conditioning with an underwater vibratory source. Animals had a gradually decreasing amount of generalization to amplitude changes, suggesting a perceptual dimension of loudness. Animals generalized largely or completely to the same underwater source presented at a range of source azimuths. When these azimuths were presented at a transect of 3 cm, some animals did show decrements in generalization, while others did not. This suggests that although azimuth may be perceived more saliently at distances closer to a dipole source, perception of position is not immediately salient in conditioned vibratory source detection. Differential responding to test stimuli located toward the head or tail suggests the presence of perceptual differences between sources that are rostral or caudal with respect to the position of the animal or perhaps the head. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

N-methyl-D-aspartate receptor antagonist MK-801 impairs learning but not memory fixation or expression of classical fear conditioning in goldfish (Carassius auratus).

Examined in 5 experiments the amnestic effects of the noncompetitive antagonist MK-801 on visually mediated, classic fear conditioning in goldfish (Carassius auratus). MK-801 was administered 30 min before the training session on Day 1 to look for anterograde amnestic effects, immediately after training to look for retrograde amnestic effects, and before the training or test session, or both, to look for state-dependence effects. Results show that MK-801 produced anterograde amnesia at doses that did not produce retrograde amnesia or state dependency and did not impair the expression of conditioned or unconditioned branchial suppression responses (BSRs) to the conditioned stimulus (CS). Results indicate that MK-801 disrupts the mechanism of learning of the CS–unconditioned stimulus (UCS) relation. Evidence is also presented that the learning processes that are disrupted by MK-801 occur during the initial stage of BSR conditioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Habituation in goldfish (Carassius auratus) is impaired by increased interstimulus interval, interval variability, and telencephalic ablation.

Goldfish (Carassius auratus) were fitted with electrodes and buccal catheters for monitoring EKGs and ventilations, respectively. A 2-s "light-on" stimulus was repeatedly presented to groups of fish at fixed interstimulus intervals (ISIs) of 1 or 2 min or at variable ISIs with a mean duration of 1 or 2 min. Normal fish, fish with telencephalic ablation, and fish with sham operations were compared for responsiveness and habituation to repeatedly presented stimuli. The longer the ISI, the greater the number of stimuli that were required for habituation. Increased ISI variability also decreased the rate of habituation. Furthermore, fish with telencephalic ablation had significantly slower habituation rates with both fixed and variable ISI schedules. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

NMDA receptor antagonist MK-801 blocks learning of conditioned stimulus-unconditioned stimulus contiguity but not fear of conditioned stimulus in goldfish (Carassius auratus L.).

The blockade of learning of Pavlovian fear conditioning by the N-methyl-D-aspartic acid (NMDA)-receptor antagonist MK-801 was examined in 166 goldfish. In previously untrained fish, MK-801 blocked learning of a light-off or a tone conditioned stimulus (CS) paired with an electrical shock unconditioned stimulus (UCS). Pretraining on the light-off CS did not affect the rate of learning of the tone CS but protected the tone learning from disruption by MK-801. Switching from the light-off to the tone CS changed the identity of the CS but not its temporal contiguity with the UCS. Pretraining consisting of pseudoconditioning of the light-off CS did not protect subsequent tone learning from blockade by MK-801. Thus, the NMDA receptor functions are necessary for learning related to the temporal contiguity of the CS and UCS but not to the identity of the CS as a cue to the occurrence of the fearful effects of the UCS. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social learning in the golden hamster (Mesocricetus auratus).

Investigates whether golden hamster (Mesocricetus auratus) pups can acquire a new behavior by interacting with an experienced adult conspecific. The behavior consisted of using teeth and forepaws to retrieve a piece of food dangling from a small chain. Instrumental learning techniques were used to train the demonstrators. Four groups of pups were exposed to different kinds of social experience. In the 1st group, the pups interacted with their skilled mother, in the 2nd group, they did the same with their inexperienced mother, in the 3rd group, they interacted with inexperienced littermates; and in the 4th group, the pups were tested individually. At the end of an acquisition period, the pups were tested individually to assess their performance. Results demonstrate that interacting with a skilled mother has a remarkable effect on the acquisition of a new feeding behavior by hamster pups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Peptide Effects on Social Behavior: Effects of Vasotocin and Isotocin on Social Approach Behavior in Male Goldfish (Carassius auratus).

The authors measured the effects of centrally infused peptides on social approach behaviors in goldfish (Carassius auratus), a social teleost. Vasotocin (VT) inhibited approach responses toward the visual stimuli of conspecifics in the absence of aggressive or sexual olfactory contextual cues in males, and a V1 receptor antagonist stimulated such responses, at least in males that were not highly social in baseline conditions, as did isotocin (IT). In the absence of social stimuli, VT did not affect activity, therefore indicating that the inhibition was not the result of nonspecific effects on arousal or motor functioning. These experiments indicate that VT and IT induce opposite effects on social approach responses in male goldfish and that endogenous VT, at least, is associated with levels of sociality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Habituation of fright and arousal responses in the teleosts Carassius auratus and Rutilus rutilus..

Examined the habituation of fright and arousal responses of the goldfish and roach to the repeated operation of a plunger in the water. The early response was fright, which habituated, and then the response characteristic of arousal appeared, which habituated as well. Longer intervals between stimuli required more presentations of the stimulus for habituation to occur in goldfish. Roaches required more presentations of the stimulus than goldfish for the responses to habituate, and telencephalic ablation severely impaired habituation of arousal, though not fright responses. Results are discussed in relation to recent work on arousal, habituation, and telencephalic function in fish. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Organization of mating behavior in male hamsters (Mesocricetus auratus).

Factor analysis was applied to standard measures of sexual behavior in 73 male hamsters (Mesocricetus auratus) as they interacted with hormone-primed females. The results suggest that 5 factors, or conceptual mechanisms, function in the organization of the behaviors observed in the first 2 copulatory series. Of these, the 3 that relate to the behaviors in the first copulatory series were compared to those emerging from prior analyses of other rodents. These comparisons revealed similarities and differences in factor structure across species. Whereas all of these analyses identify factors related to the initiation and efficiency of copulatory behavior, hamsters seem to differ from other species in the measures that best define these factors. In addition, the copulatory rate factor that has been prominent in previous analyses of rats seems to be absent in hamsters. These results suggest that male sexual behavior in hamsters is organized differently from that in other rodents. In more general terms, they suggest that even species with generally similar copulatory patterns can show significant differences in behavioral organization, in turn suggesting the need for additional factor analytic studies to better establish the extent of these species differences. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Preference for novel flavors in adult golden hamsters ( Mesocricetus auratus ).

Although animals generally prefer to eat foods with familiar rather than unfamiliar flavors, adult golden hamsters (Mesocricetus auratus) were found to do the opposite. After having prolonged exposure to a food with a particular flavor, hamsters were allowed to select between the food with the familiar flavor and the same food with a novel flavor. Hamsters consistently ate more of the food with the novel flavor, and this preference was long-lasting and resistant to extinction. Furthermore, the novelty effect was robust, being manifested in both sexes and under a variety of experimental circumstances. In contrast, rats tested under identical conditions consistently preferred the food with the familiar flavor. The origins of the novelty effect in hamsters remain to be determined. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Serotonin regulation of aggressive behavior in male golden hamsters (Mesocricetus auratus).

These studies examined the neurochemistry and neuroanatomy of the serotonin (5-HT) system innervating the anterior hypothalamus (AH) and the interaction of 5-HT receptor agonists with arginine vasopressin (AVP) in the regulation of offensive aggression in golden hamsters. Because specific 5-HT1A, 5-HT1B, and AVP V1A binding sites were observed within the AH by in vitro autoradiography, the hamsters were tested for offensive aggression after microinjections of AVP in combination with either the 5-HT1A agonist 8-hydroxy-2-(di-n-propylarnino) tetraline (DPAT) or the 5-HT1B agonist CGS-12066A (CGS) directly within the AH. Though treatment with DPAT resulted in a dose-dependent inhibition of AVP-facilitated offensive aggression, CGS was ineffective. In addition, a retrograde tracer was injected within the AH to localize the distribution of 5-HT neurons projecting to the area. Retrogradely labeled 5-HT neurons were found within the dorsal, median, and caudal linear raphe nuclei and are suspected to inhibit AVP-facilitated offensive aggression by an activation of 5-HT1A receptors in the AH. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of the interintromission interval on lordotic response and attack latency in golden hamsters (Mesocricetus auratus).

After 12–25 ejaculatory series, each consisting of several short intromissions (2- to 3-s vaginal penetration) and an ejaculation, male golden hamsters adopt an altered copulatory pattern consisting of long intromissions (5- to 25-s penetration with intravaginal thrusting). Receptivity declines and the tendency for the female to attack the male increases at about the time of this shift in copulatory pattern. Because the mean interintromission interval (III) between short intromissions is about 8 s compared to 100 s between long intromissions, it is possible that females detect this difference and adjust their mating accordingly. When the III between short intromissions from a rested male experimentally increased to 100 s by use of a halter and lead device, the duration of lordosis was significantly less than that displayed by females paired with control males (8-s III) and virtually the same as that displayed by females paired with males that produced only long intromissions. This suggests that the female uses the temporal patterning of intravaginal stimulation as one criterion for terminating mating with a particular male. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Behavior of attack-primed and attack-satiated female golden hamsters (Mesocricetus auratus).

In 3 experiments with 50 female hamsters, "priming" the S by allowing it one biting attack on a smaller, methotrimeprazine-treated target hamster significantly decreased its latency to attack a subsequently presented probe target. Conversely, the latency of attacks on the probe was increased, and the number of attacks decreased, if the S was first "satiated" by allowing it 1 hr of ad-lib access to a target followed by a series of briefer target presentations until a criterion of 3 successive presentations without attack was met. The respective aggression-increasing and aggression-decreasing effects of these manipulations were also demonstrated in more naturalistic, unrestrained encounters between pairs of Ss that had just been exposed to the same manipulation. Neither manipulation affected the nonaggressive behaviors of sunflower seed acceptance and wheel running, which suggests that the effects of attack priming and satiation may be specific to aggression. (39 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)