Observation learning in day-old chicks using a one-trial passive avoidance learning paradigm

The ATP-binding cassette (ABC) transporters belong to a large superfamily of proteins which share a common function and a common nucleotide-binding domain. The CvaB protein from Escherichia coli is a member of the bacterial ABC exporter subfamily and is essential for the export of the peptide antibiotic colicin V. Here we report that, surprisingly, the CvaB carboxyl-terminal nucleotide-binding domain (BCTD) can be preferentially cross-linked to GTP but not to ATP at low temperatures. The cross-linking is Mg2+ and Mn2+ dependent. However, BCTD possesses similar GTPase and ATPase activities at 37 degrees C, with the same kinetic parameters and with similar responses to inhibitors. Moreover, a point mutation (D654H) in CvaB that completely abolishes colicin V secretion severely impairs both GTPase and ATPase activities in the corresponding BCTD, indicating that the two activities are from the same enzyme. Interestingly, hydrolysis activity of ATP is much more cold sensitive than that of GTP: BCTD possesses mainly GTP hydrolysis activity at 10 degrees C, consistent with the cross-linking results. These findings suggest a novel mechanism for an ABC protein-mediated transport with specificity for GTP hydrolysis.     

Ontogeny of conditioned inhibition in domestic chicks.

Used the combined-cue test to measure age-dependent changes in learned stimulus inhibitory control in 40 young Vantress * Arbor Acre chicks trained to key peck for heat reinforcement. Both 1- and 4-day-old chicks were given either 96 or 384 discrete trials in a successive discrimination test, and then their response latencies to the novel combined cue (S+, S-) and the prior S+ cue were compared with those of age-matched controls during extinction. Major findings are as follows: (a) One-day-old chicks showed significant response suppression to the combined cue only after receiving 384 discrete trials, whereas 4-day-old chicks showed significant response suppression after both 96 and 384 trials. (b) While control chicks (S+ training only) of both age groups pecked more quickly at the novel cue than at the prior S+ cue during extinction, only the younger chicks pecked more quickly at the novel cue as the number of their prior S+ responses increased. The main conclusion from these experiments is that even the 1-day-old chick has the capacity to acquire learned inhibitory stimulus control but does so at a slower rate than the 4-day-old chick. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Enhancement of effectiveness of learning by testosterone in domestic chicks.

In 4 experiments with 20 2–3 day old male Warren Sex-link chicks, the presentation of a nonaversive colored bead to be pecked (pretraining) interfered with subsequent avoidance training in which the bead presented tasted unpleasant, when only 2 conditions were fulfilled: (a) Beads used at pretraining and training were of similar appearance, and (b) testosterone was injected either before or shortly after pretraining. This effect of the hormone was not a consequence of changes in behavior at training or at test. Rather, it appeared to reflect changes during the consolidation of the pretraining memory trace that made it more effective in subsequent competition with training. Beads that were blue in color were unusual in evoking high levels of avoidance in naive Ss and, when used in pretraining in the presence of testosterone, in failing to oppose subsequent training on the blue bead. Such pretraining became effective when paired with avoidance training with a bead of different color, apparently by changing the information stored about pretraining. (37 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stress and behavior in streptozotocin diabetic rats: Biochemical correlates of passive avoidance learning.

Retention of one-trial passive avoidance training was compared in diabetic and nondiabetic rats. Also compared were corticosterone concentrations associated with both training and retention testing, catecholamine excretion related to training, and regional brain catecholamine concentrations accompanying retention testing. Diabetic rats showed significantly better retention for the task than did nondiabetic rats. Associated with retention differences, diabetic rats had higher epinephrine excretion and nondiabetic rats had lower excretion after footshock training relative to baseline measures. Norepinephrine excretion was elevated in diabetics both in baseline measurement and during the 24 hr following footshock training. Diabetic rats had higher concentrations of norepinephrine (NE) and dopamine (DA) and lower 3,4-dihydroxyphenylacetic acid/dopamine {dopc/da} ratios in hypothalamus and higher NE in brain stem and amygdala than did nondiabetics, although both diabetic and nondiabetic rats had reduced DS and NE following retention testing. The results indicate that there are biochemical alterations in diabetes that may have important behavioral impact. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of nitric oxide in passive avoidance learning

The role of nitric oxide on passive avoidance learning was studied by administering L-arginine or D-arginine to male rats in a passive avoidance paradigm. L-Arginine administered into the lateral brain ventricle at a dose of 1.25 microg showed a tendency to increase the passive avoidance latency, and 2.5 microg exerted almost maximal action, but the action gradually increased still further up to 20 microg tested. D-Arginine had no action. Peripheral administration (intraperitoneal) of L-arginine facilitated the consolidation of passive avoidance learning in a dose-dependent manner. A significant increase in passive avoidance response was obtained following an injection of 100 mg/kg L-arginine. When L-arginine was given i.c.v. with a selected dose of 5 microg, 30 min prior to a learning trial, the latency of the passive avoidance response was likewise lengthened. However, when L-arginine was given 30 min before the 24-hr testing (retrieval), it was ineffective. It was also ineffective when given 6 hr after the training trial. However, when L-arginine was administered immediately following the training trial, the action in improving the consolidation could be detected 6 hr after the training trial. Nitro-L-arginine, which blocks nitric oxide synthase, can also block the facilitation of consolidation caused by the nitric oxide donor L-arginine. The nitric oxide synthase inhibitor per se in different doses had no action on the learning of a passive avoidance task. The results indicate that nitric oxide is able to facilitate the learning and consolidation of memory in a passive avoidance paradigm, but it is ineffective in retrieval processes. The results also suggest that, under the experimental circumstances used, nitric oxide is involved only in the facilitated learning and memory processes caused by pharmacological effect of L-arginine, and not involved in normal learning processes.     

Stimulus preexposure and discrimination learning by domestic chicks: Effect of varying interstimulus time.

Conducted a series of experiments with a total of 199 Ross strain chicks in which groups of Ss were preexposed to moving objects on Days 1-5 after hatching. Only 1 object was visible at a time, and the time between the appearance of one stimulus and the immediately succeeding appearance of the other was called the "interonset time." Ss which had been preexposed to both discriminanda in rapid alternation (interonset time of 1/4 min) learned a subsequent discrimination task more slowly than Ss familiar with neither stimulus; Ss preexposed to both discriminanda at separate times (interonset time of 30 min) learned the discrimination faster than Ss familiar with neither stimulus. The evidence suggests that the proportions of slow-learning and fast-learning Ss in a group were changed by varying interonset time. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reaction to punishment, reflectivity, and passive avoidance learning in extraverts.

Passive avoidance learning occupies a central role in accounts of disinhibited behavior, ranging from psychopaths' persistent criminality (Hare, 1970) to extraverts' gregariousness (Gray, 1972). To explore the mechanism underlying passive avoidance deficits, we assessed the relation of extraversion, neuroticism, and response latency after punishment to passive avoidance learning by using two successive go/no go discrimination tasks. The tasks were designed to examine two aspects of subjects' reactions to punishment: response speed on trials immediately following punishment (Experiment 1) and time to terminate punishment feedback between successive trials (i.e., reflectivity; Experiment 2). Consistent with previous findings, the results of Experiment 1 showed that extraverts commit more passive avoidance errors than introverts do (Newman, Widom, & Nathan, 1985) and fail to pause following punished errors (Nichols & Newman, 1986). In Experiment 2, only neurotic extraverts displayed this pattern of performance differences. In both experiments, longer pausing following punishment predicted better learning from punishment for both introverts and extraverts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Activation of domestic chicks.

Given prior results showing reinforcement effects for contingent light onset in day-old Leghorn chicks, the present series of studies examined effects of noncontingent light presentation using the same operant as an index of activity. Ss were a total of 641 White Leghorn cockerel chicks between 24-36 hrs old. Results show a strong, consistent topography of activity which depended upon the same parameters known to influence reinforcement effects in these Ss. Activation is suggested as a process and a means for prediction or reinforcement effects-particularly when the topography of activation is compatible with behavioral requirements of a reinforcement contingency. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of scopolamine on activity and passive avoidance learning in rats of different ages.

A total of 320 albino CFE Sprague-Dawley rats aged 16-17, 20-21, 24-25, 28-29, and 70-85 days old were injected intraperitoneally with either scopolamine hydrobromide (SCOP-HBr) or scopolamine methylnitrate (SCOP-Me-NO-3) at 4 levels (0, .5, 1.9, or 2.0 mg/kg. The SCOP-HBr but not he SCOP-Me-NO-3 disrupted passive avoidance in Ss aged 20-28 days. A subsequent replication at higher doses (4.0, 8.0, and 16.0 mg/kg) with 56 70-84 day old adults and 64 16-day-old pups indicated that SCOP-HBr could disrupt passive avoidance in the adults but not in the pups. Results are consistent with the hypothesis that a cholinergic inhibitory system which mediates passive avoidance develops in the rat 16-20 days postnatally. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-dependent improvement in passive avoidance learning of the young chick: Cholinergic mediation?

Studied cholinergic mediation of the age-dependent improvement in response suppression of the young chick by determining the performance of 144 Vantress?×?Arbor Acre 4-day-old chicks, pretreated with scopolamine (SCO), during passive avoidance (PA) and extinction testing. In Exp I, Ss were trained to keypeck for heat reward (prepunishment training), and then tested for PA learning under immediate, 2-sec-delayed, or no shock condition. Half of the Ss in each condition received saline injections before prepunishment training and .5 mg/kg SCO injections after training. The rest received .5 mg/kg SCO injections both before and after training. For Ss in both SCO groups, delaying shock onset resulted in significantly less response suppression than immediate response-contingent shock. In Exp II, 4-day-old Ss injected with saline or SCO were trained to keypeck for heat reward and then tested for resistance to extinction under response-contingent shock or nonshock conditions. Punishment decreased the number of extinction responses for both saline and SCO groups. Results indicte that the age-dependent improvement in response suppression of the young chick cannot be explained solely by a significant increase in central cholinergic functioning. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Disruption of passive avoidance learning in the rat by electrical stimulation of the hippocampus.

Five experiments, with 184 male albino rats, examined the effect of electrical stimulation to discrete regions of the dorsal hippocampus on passive avoidance. Ss stepped from a brightly lit, white compartment to a dark compartment. Following footshock in the dark compartment, step-through latencies were recorded 1 min, 24 hrs, and 48 hrs after footshock. When given 20 step-through trials prior to footshock, dentate-stimulated Ss exhibited lack of passive avoidance with particularly short latencies at 1 min, and CA1-stimulated Ss showed reduced latencies compared with latencies of cortical and nonoperated controls. In Exp II, Ss given stimulation in the same regions performed the avoidance task without prior step-through experience. All groups showed less passive avoidance than the control group in Exp I, and there were no significant differences between groups. With a single step-through trial before the footshock trial, longer avoidance latencies were recorded, but again groups did not differ significantly. Dentate-implanted Ss, given 20 prior exposure trials but with stimulation at different stages of the task sequence, demonstrated a passive avoidance deficit at 1 min after footshock. Results are discussed in terms of the generation of expectancy that the black compartment was a safe place and the effects of brain stimulation on the expectancy, with particular reference to O. S. Vinogradova's (1975) theory of hippocampal function. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Approach and avoidance motivation in psychopathic criminal offenders during passive avoidance.

The authors evaluated competing theories that attribute psychopathic individuals' poor passive avoidance to a strong activating system, a weak inhibitory system, or poor modulation of behavioral activation when inhibitory cues appear. In Study 1, the continuous motor task involved a reward phase to elicit the activating system followed by a passive avoidance phase. Study 2 tested the generality of the theories by using an active avoidance phase to elicit the activating system. Heart rate and response speed results from Study 1 best supported the strong activating system and poor response modulation models in low-anxiety psychopathic offenders. Study 2 results did not clearly support any of the models. Further research is needed to determine if excessive activation by reward and poor response modulation are associated with passive avoidance deficits and other characteristics of low-anxiety psychopathic offenders. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Social discrimination and aggressive pecking in domestic chicks.

Free interaction among 192 White Leghorn chicks involved inter-S pecking. During tests as early as 1 day after hatching, socially reared Ss showed reliable social discriminations by pecking more at strangers than at cage mates. Compared with socially reared birds, Ss reared in isolation exhibited certain exaggerated or atypical response patterns. Patterns included heightened rates of inter-S pecking, a pronounced tendency to peck at the head, elevated emotionality as reflected in the distress call, and the failure of pair-mates to show matched rates of environmental pecking. Inferences are drawn from these patterns, with the conclusion that infantile inter-S pecking in chicks may be based on aggressive rather than strictly exploratory tendencies. Findings are discussed in terms of the development of a basic tolerance for conspecifics and early social orderings. (52 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of multiple peer separation in domestic chicks.

Determined if domestic chicks respond to multiple social separations with the cumulative disruption of social development seen in other species. 12 pairs of White Leghorn chicks were separated and reunited 15 times over 7 wks. The 1st 3 separations were 72 hrs each; the remaining 12 each lasted 24 hrs. Reunions were of the same length as the corresponding separations. Daily observations were supplemented with measures of Ss' reactions to unfamiliar conspecifies and environments. As a group, the separates were sensitive to every separation and every reunion. One facet of the separates' social behavior was apparently affected by these separation–reunion episodes: There was a reduction in the degree to which the separates matched one another's food-peck responses, indicating a possible deficit in their social propensities. However, the separates' behavior tended toward control levels within the 72-hr separation periods, across the series of day-long separations, and in the supplemental tests. In sum, no broadly debilitating effect comparable to that found in primates was seen. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of social isolation and social separation in domestic chicks.

Conducted 2 experiments with 60 white Leghorn chicks, with subsamples of 24 and 36 animals tested in 2 independent replications, to assess the impact of early social isolation and social separation on the behavior of domestic chicks. In Exp I, a 3-wk longitudinal study, the day-to-day behavior of isolated chicks was compared to the behavior of birds housed in pairs. Ss in a 3rd group were reared in pairs for 2 wks, and then were permanently separated. The daily observations of all Ss recorded disturbance reactions, exploratory activities, consummatory behavior, grooming, and inactivity. In Exp II, 36 Ss from the 3 experimental conditions were tested in the 4th posthatch week for general social responsiveness in the presence of unfamiliar conspecifics. Results show that (a) both isolation and separation produced behavioral anomalies; (b) separated Ss' reactions indicated patterns analogous to post-separation patterns seen in other species; and (c) the effects of isolation and separation were not qualitatively equivalent--exposure to conspecifics revealed antisocial behavior in the isolates, relative to the responses of their socially reared and separated counterparts. Results are discussed in terms of a model for differences in the essence and consequences of early social isolation and social separation. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hippocampal function in avoidance learning and punishment.

Discusses the effects of hippocampal lesions in avoidance and punishment situations. It is proposed that animals with such lesions cannot process information about places and therefore cannot employ place strategies in avoidance learning and punishment situations; they can only employ cue strategies that involve learning to approach or avoid a cue or to perform a response in the presence of a cue. Intact animals, on the other hand, can employ both place and cue strategies. The data are, to a large extent, consistent with this hypothesis. Implications for theories of learning in situations involving aversive reinforcers are discussed. (125 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sensory responsiveness and avoidance learning in rats.

Conducted an analysis of sensory responsiveness and avoidance learning in 3 experiments using 5 rat strains: MNR/Har/Lu, MR/Har/Lu, RCA/Lu, RHA/Lu, and RLA/Lu. Ss totaled 470. There were significant differences among the strains in response to electric footshock. Also, the strain-specific shock intensity as the UCS elicited significantly higher rates of avoidance learning as compared with the rates of avoidance learning under an equal but average level of shock intensity as the UCS. In general, discrete auditory and visual sensory modes as the CS produced almost the same rate of avoidance learning. The proportion of variation in avoidance learning attributable to strains was significant under all 6 experimental conditions except the no-discrete CS and strain-specific UCS conditions. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Learning in domestic chicks after exposure to both discriminanda.

P. P. Bateson and D. F. Chantrey (see record 1972-30989-001) have suggested that the characteristics of complex objects may be learned by young animals by sequential exposure to parts or views of the object. The various component stimuli are said to be "classified together" as the animal learns to perceive its world. Consequently, domestic chicks given the opportunity to classifty together color stimuli are subsequently less able to discriminate between them than are controls. Nine experiments with 171 Shaver Starcross Leghorn and Vantress broiler chicks were designed to investigate this phenomenon further. Ss were exposed either to colors or to shapes and subsequently trained to discriminate between them, and their discrimination performance was compared with that of nonexposed controls. In only 2 experiments, one of them a near replication of Bateson and Chantrey's work, were their findings reproduced. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related deficits in acquisition of a passive avoidance response.

In Exp. I, 80 male albino rats 10, 15, 20, 30, or 100 days old received a brief inescapable shock contingent upon making a step-off response. Step-off latencies increased for all age groups, but rate of learning was significantly faster in older Ss. Learning appeared to be based primarily upon punishment effects rather than general emotionality, since yoked Ss shocked after being placed directly on the grids did not acquire the avoidance response. Exp. II with 120 Ss employed 3 training conditions with independent groups 12, 15, 18, or 21 days old. The step-off response resulted in shock that was either: (a) escapable; (b) inescapable, 1-sec duration; or (c) inescapable, yoked duration. Younger Ss were again significantly inferior to more mature Ss. Escapable shock improved acquisition at 2 age levels, but the effect appeared to be more related to shock duration than to the response contingency. It is suggested that the requirement of withholding a punished response may represent a category of learning that is especially sensitive to maturational changes. (French summary) (16 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)