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)     

Effects of genotype and postnatal experiences on activity, avoidance, shock threshold, and open-field behavior of rats.

Studied the effects of postnatal experience in 6 experiments on the activity, avoidance, shock threshold, and open-field behavior of 91 selectively-bred Ss from high-avoidance (RHA/Lu) strains and 93 from low-avoidance (RLA/Lu) strains. Significant differences were found between postnatal experiences in shuttle box activity, but strain differences were not significant. The high-avoidance Ss acquired avoidance learning significantly faster and had lower shock thresholds than the low-avoidance Ss. However, postnatal experience had significant effects on avoidance and shock threshold only in the high-avoidance Ss. No significant strain differences were found in open-field behavior, and the postnatal experience effects showed only higher order significant interactions. Results are discussed in the framework of quantitative genetics and a direct-action hypothesis of postnatal experience. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interaction among genotype, unconditioned stimulus, d-amphetamine, and one-way avoidance behavior of rats.

In the genetic analysis of avoidance learning, questions relating to the generality to other avoidance behaviors and the role of motivation were investigated in 61 RHA/Lu and 61 RLA/Lu rats. Significant differences were found in 1-way avoidance behavior of the strains selectively bred for 2-way active avoidance. In 6 experiments, these differences in 1-way avoidance either disappeared or were minimized to a great extent under the effects of dextroamphetamine. The experimental manipulation of motivation (i.e., unconditioned stimulus shock level equivalent to the unconditioned flinch, jump, and fleeing response measures) accounted for only part of the variation in avoidance learning of these strains. Results are discussed in the terms of inverted-–U arousal function and quantitative genetics. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Arousal explains difference in avoidance learning of genetically selected rat strains.

Manipulated task complexity differences in avoidance learning of genetically selected strains of rats under dextroamphetamine (1, 2, and 4 mg/kg, ip). 288 Ss from RHA/Lu, RLA/Lu, RCA/Lu, RHA by RLA, and RLA by RHA strains were studied. With decreasing levels of task complexity the differences in avoidance learning between the selectively bred strains decreased significantly. Under the lower levels of complexity the strains reversed their relative positions in avoidance learning. Results are discussed in terms of inverted-–U arousal function. The factors investigated in this study indicate that the differences in avoidance behavior of these lines of rats may be understood as deriving from genetically related different levels of arousal. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Erratum to Satinder.

Reports an error in the article "Arousal Explains Difference in Avoidance Learning of Genetically Selected Rat Strains" by K. Paul Satinder (Journal of Comparative and Physiological Psychology, 1977, Vol. 91, No. 6, pp. 1326-1336), one line was printed incorrectly. On page 1331, the last line of Table 2 reads as follows: RNA/Lu oneway 193 280. The line should be changed to read as follows: RHA/Lu oneway 193 280. (The following abstract originally appeared in record 1978-22592-001) Manipulated task complexity differences in avoidance learning of genetically selected strains of rats under dextroamphetamine (1, 2, and 4 mg/kg, ip). 288 Ss from RHA/Lu, RLA/Lu, RCA/Lu, RHA by RLA, and RLA by RHA strains were studied. With decreasing levels of task complexity the differences in avoidance learning between the selectively bred strains decreased significantly. Under the lower levels of complexity the strains reversed their relative positions in avoidance learning. Results are discussed in terms of inverted--U arousal function. The factors investigated in this study indicate that the differences in avoidance behavior of these lines of rats may be understood as deriving from genetically related different levels of arousal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Behavior-genetic-dependent self-selection of alcohol in rats.

Investigated self-selection of alcohol in 30 male and 30 female selectively bred rats: MNR/Har/Lu (f38), MR/Har/Lu (f33), RCA/Lu (F18), RHA/Lu (F18), and RLA/Lu (F18). In Exp. I, self-selection of alcohol of 3 concentrations was tested along with caloric-equivalent glucose solutions and distilled water. Exp. II investigated the simultaneous self-selection of 5, 10, and 20% alcohol solutions. In Exp. III effects of food deprivation on the self-selection of 10% alcohol and distilled water were studied. Self-selection of alcohol was related to the phenotypes of emotional reactivity and avoidance conditionability. Females consumed significantly larger amounts of absolute alcohol than males based on corrected body weight. Validity of sex differences is discussed. (30 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developmental aspects of recovery of function following septal lesions in the infant rat.

In an experiment with 4 litters of Long-Evans hooded rats (14 pups/litter), 1/2 of each litter received septal lesions at the age of 7 days, and the remaining 1/2 received control operations (incision). Septal lesions in infant Ss resulted in hyperemotionality and altered open-field behaviors at the ages of 21, 42, 63, and 90 days. When Ss reached 90 days of age, their behavior was compared with that of normal adult rats and rats that had received septal lesions in adulthood. Measures of active avoidance, fixed-ratio responding, and social facilitation were collected for all groups. Results show that septal lesions in infancy or adulthood enhanced avoidance responding, fixed-ratio responding, and social behavior when compared with infant or adult controls. Failure to observe recovery of function was interpreted in terms of phylogeny and hierarchical cerebral organization. (26 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A reevaluation of the relation between estrogen and emotionality in female rats.

It has been hypothesized that the emotionality of the female rat is reduced at estrus. In confirmation of previous research, the present 5 experiments with 112 Ss show that administration of estradiol benzoate (20 mug/kg) to female rats of the Maudsley Reactive (MR) strain increased open-field activity and decreased open-field defecation. In addition, ovariectomy increased open-field defecation in MR females. Supporting the generality of these findings, hormone administration reduced open-field defecation and increased open-field activity in intact females of a genetically heterogeneous background. Additional studies suggest that the decrease in open-field defecation at estrus is dependent on estrogenic suppression of food intake. Hormone replacement decreased food intake in the period preceding the open-field test, and colonic contents were also lower in rats treated with estradiol benzoate plus progesterone immediately after the completion of the open-field test. These changes were seen in both MR and genetically heterogeneous females. It is concluded that the decrease in open-field defecation at estrus may be mediated by a reduction in food intake and a consequent decrease in colonic contents and that the validity of the defecation response as a measure of emotionality may be seriously questioned under these circumstances. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Locomotor, avoidance, and maze behavior in rats with selective disruption of hippocampal output.

Investigated behavioral correlates of selective disruption of hippocampal output in a series of 5 experiments. A total of 136 male albino Moll-Wistar rats were used as Ss. In 2 experiments an attempt was made through behavioral investigation to determine whether the CA1 neurons project to the fimbria or to the subiculum. Results support recent views that the subiculum is the recipient of CA1 axons. Disruption of the CA1 output in the dorsal hippocampus of Ss produced increased open-field activity, whereas passive avoidance and spontaneous alternation behaviors remained unchanged. No differentiation was obtained between CA1 damage and neocortical lesions in maze learning. Blocking of the fimbrial CA3 output from the dorsal hippocampus improved passive avoidance performance and impaired active avoidance performance, whereas open-field and spontaneous alternation behaviors were unaffected. Interruptions of the CA3 output from the ventral hippocampus improved active avoidance performance and reduced spontaneous alternation behavior. Open-field behavior and passive avoidance performance remained unchanged. Total fimbrial sections increased open-field activity, improved passive and active avoidance, and reduced spontaneous alternation. Results are discussed in terms of functional differentiation between the CA1 and CA3 of the dorsal hippocampus aknd in terms of functional in the fimbrial CA3 output from the dorsal and ventral hippocampus. (56 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Behavioral effects of environmental enrichment in randomly bred mice.

Reared 212 randomly bred mice from birth in an enriched environment or in a standard control environment. Ss were tested for open-field activity and defecation, running wheel activity, exploration, and hoarding. After the hoarding tests all Ss were sacrificed and adrenal glands were removed and weighed. Significant main effects due to treatment were found on gross body weight at 38 days of age, open-field activity and defecation, running wheel activity measures, and exploration. Correlational analyses revealed that open-field activity was positively associated with exploratory behavior, and that the 2 activity measures were positively associated. In the control Ss, the running wheel measures were positively associated with hoarding performance. Results are discussed and compared with previous studies of environmental enrichment and mouse behavior. It is concluded that the effects of early enrichment upon open-field activity, running wheel activity, and exploration are well established. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Genetic differences in avoidance learning by Rattus norvegicus: Escape/avoidance responding, sensitivity to electric shock, discrimination learning, and open-field behavior.

Studied the behaviors of Long-Evans rats selectively bred for either good (SHA line) or poor (SLA line) shuttle box avoidance learning. The results of Exp I indicated that the phenotypic difference in avoidance learning was not associated with differences in speed of escape or avoidance responding. Differences between the lines in frequency of intertrial responses (ITRs), which appeared during training but not during pretest, suggest that ITRs in Ss of the low-avoidance SLA line were more suppressed by electric shock than in Ss of the high-avoidance SHA line. This result suggests that SLA Ss may be more emotionally responsive than SHA Ss. Exp II demonstrated that the Ss of the 2 lines did not differ in absolute sensitivity to electric shock, and Exp III showed that the poor performance of the SLA line was not due to an inability to learn. Ss also provided evidence that the poor avoidance learning by SLA Ss was due to their emotional reactivity. Observations of open-field behavior in Exp IV were consistent with this hypothesis. It is concluded that the major consistent correlate of the phenotypic difference in avoidance learning was greater emotionality or emotional reactivity in SLA than in SHA Ss. (57 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An association between granule cell density in the dentate gyrus and two-way avoidance conditioning in the house mouse.

In 2 experiments, 102 hybrid male mice (C57BL/6J and C58/J stock) with genetically associated variations in the number and density of granule cells in the dentate gyrus were tested for open-field activity, spatial maze learning, and 2-way avoidance conditioning. The number of granule cells was not associated with any behavior. Only avoidance conditioning was related to granule cell density, which had a negative correlation with performance on the shuttlebox task. This result was replicated in 2 genetically different stocks of mice. Density of the more caudal portion of the dentate was associated with early stages of avoidance learning, whereas the more rostral portion was associated with later stages. Results are discussed in relation to theories of functional dissociation within the hippocampus. (38 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ontogeny of aggressive-sexual behavior between males in lines of Japanese quail (Coturnix coturnix japonica) selected for male mating frequency.

100 male Japanese quail, from lines bidirectionally selected for high and low mating frequency and from a random-bred base population, were observed in an ontogenetic study of aggressive/sexual behavior. Ss were reared in sex-intermingled flocks until 28 days of age, at which time half of the Ss from each line were housed as all-male flocks and half were transferred to individual cages. At 41 days of age, individually caged Ss exhibited mounting behavior to win encounters with other Ss. By 45 days, Ss from the high and control lines exhibited significantly more aggressive sexual behavior than those from the low lines. Line?×?Rearing Experience interactions for mounting behavior at 45 and 56 days of age were due to the individually caged high- and control-line Ss' winning encounters by mounts; those maintained in flocks rarely mounted. Although some low-line Ss won encounters by mounts, the occurrence of this behavior was infrequent. Ss maintained in flocks were placed in individual cages at 57 days of age. When these Ss and those housed in individual cages from 28 days of age were compared at 84 days of age and older, the Line?×?Rearing Experience interaction observed previously disappeared, and only differences among genetic lines were evident. Genetic and rearing experience effects are discussed as influencing agonistic and sexual behaviors. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Maudsley reactive and nonreactive strains: a North American perspective

The Maudsley experiment involving bidirectional selection for differences in open-field defecation (OFD) is briefly reviewed. Attention is focused on the North American stocks of these strains since problems have been encountered with regard to the open-field behavior and continued viability of the British stocks. The open-field behavior of the colonies of the Maudsley strains at the National Institutes of Health and at the University of Northern Iowa closely resembles that originally exhibited by the British strains, provided they are compared under standard conditions. On more complex behaviors, such as escape-avoidance conditioning, serious discrepancies have emerged between the British and North American findings. These may be resolved when attempts are made to replicate more closely the procedures used in the British studies. Particular emphasis has been placed on the potential of a second nonreactive strain, the MNRA/HAR strain, to serve as a replicate of selection for decreased emotionality. The value of the RXNRA group of recombinant-inbred strains, developed and maintained by the author, for examining the reliability of associations between traits is also stressed. A correlation between OFD and biochemical aspects of sympathetic function has been found in the Maudsley strains. This finding lends credibility to Hall's claim that the expression of emotionality is linked to autonomic arousal.     

Effects of early food deprivation on mouse behavior.

Assessed the effects of early food deprivation upon open-field defecation and activity, running-wheel activity, and food-competition behavior using 76 A/J and 73 DBA/2J mice. Experimental Ss were food deprived from Day 18-27 of life for 10 hr/day. Food-deprived Ss defecated more in the open field and were less active in the running wheels. In these measures, strain and sex interacted with treatment. DBA mice which received the deprivation treatment were less competitive than the comparison Ss, but the treatment did not affect competition in the A/J Ss. It is suggested that the severity of the treatment and age when it was administered interfered with normal development of behavior. (21 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Genotype-dependent effects of septal lesions on different types of learning in the mouse.

Tested 80 C57BL/6J, DBA/2J, and SEC/1ReJ mice with septal or control lesions for exploratory behavior, shuttle-box avoidance learning, discriminated avoidance, and maze-learning ability. Control DBA and SEC Ss normally displayed low levels of exploratory behavior and efficient avoidance and maze learning. High exploratory activity and low avoidance and maze learning were characteristically shown by C57 controls. All strains with septal lesions increased levels of exploratory and avoidance behaviors. In contrast, following septal lesions the 3 strains performed more poorly in discriminated-avoidance and maze learning. It is concluded that differences in septal function-e.g., in level of response inhibition-do not substantially account for the learning differences evident between these strains. (19 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interaction of environmental enrichment and genotype.

Assessed the effects of exposure to an enriched environment, from birth-38 days of age, using 3 behavioral tests: open field, exploration, and running wheels. 144 inbred mice from 3 strains (A/J, C3H/HeJ, and C57BL/10J) were used as Ss in a 3 * 2 * 2 factorial design: 3 strains, enriched and control treatment, and males and females. Significant main effects due to strain, treatment, and trials were found in open-field activity, exploration, and running-wheel activity. Main effects due to strain and trials were found in open-field defecation. Genotype interacted with treatment on 3 of the 5 dependent measures and interacted with trials on all measures. Coefficients of genetic determination for the various dependent measures were between .08 and .43. Results support the hypothesis that environmental enrichment increased activity and decreased exploration. (28 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A test for specific and general behavioral effects of infantile stimulation with shock in the mouse.

The hypothesis tested was that exposure of the infant mouse to shock which could not be terminated by some specific response would lead to greater fearfulness later on than exposure to shock whose termination was contingent on a specific response. 3 groups of mice 8 to 11 days of age were each subjected to different shock conditions. One group could terminate the shock by an avoidance response (response-contingent group), one group had no control over the duration of shock (arbitrary shock group), and the third group received no shock in the apparatus. Later an open-field test of emotionality showed no significant differences, but an adult avoidance learning test showed that the run times of the response-contingent group were significantly shorter than those of the no-shock group. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of the nonagouti pelage-color allele on the behavior of captive wild Norway rats (Rattus norvegicus).

The objective of the present study was to determine the extent to which the nonagouti pelage-color allele influences selected behaviors (including docility) of the wild Norway rat. Agouti and nonagouti (black) littermates were compared in tests for handling, open-field behavior, platform jumping, and response to a novel food item, all of which clearly differentiate wild and domestic rats. Nonagouti rats were significantly easier to approach, capture, and handle than their agouti sibs. However, differences between agouti and nonagouti rats for the other variables studied were not significant. Although the presence of the nonagouti allele cannot fully account for the behavioral differences between wild and domestic Norway rats, it may have facilitated the domestication of this species by improving ease of handling. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of amphetamine and haloperidol on avoidance behavior and exploratory activity

The effect of graded doses of D-amphetamine and haloperidol were tested on retention of a one trial learning passive avoidance response, on extinction of pole-jumping active avoidance behavior and on open-field activity. Low doses of amphetamine (10 microgram/animal) increased passive avoidance latency when given s.c. 1 h prior to the retention test. Higher doses (20 and 1000 microgram/animal) caused a bimodal distribution of avoidance latencies. Haloperidol (0.03 or 1.0 microgram/animal) significantly attenuated passive avoidance behavior. Amphetamine caused a delay of extinction of pole-jumping avoidance behavior in a dose-dependent manner (10, 30 or 90 microgram per rat). Conversely, haloperidol induced a dose-dependent facilitation of extinction (0.03 or 0.1 microgram per rat). Open-field activity was not significantly affected by 30 microgram amphetamine or 0.03 microgram haloperidol; 90 microgram amphetamine significantly increased rearing activity and 0.1 microgram haloperidol decreased ambulation. The data show that passive and active avoidance behavior are sensitive measures to test the activity of psychomotor stimulant and neuroleptic drugs. Exploratory behavior allows more specific behavioral effects to be dissociated from locomotor influences.