摘要:

AbstractHypothyroidism was induced in neonatal Sprague‐Dawley rats by adding propylthiouracil to the lactating female's food and water. Behavioral evaluation on a 6‐item battery occurred from 70 to 114 days of age. Results indicated long‐lasting behavioral changes in the neonatal hypothyroid animals characterized by increased activity and decreased performance on avoidance and escape learning. Serum thyroxine levels were reduced in the hypothyroid animals throughout the 120‐day period. Experimental animals also had fewer synaptic contacts in the cerebellar cortex when analyzed at 90 days

ISSN:0012-1630    

DOI:10.1002/dev.420120302

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractLactating females of 2 lines of mice selectively bred for long (LS) and short (SS) ethanol‐induced sleep time (a measure of alcohol tolerance) consumed either tap water or 10% ethanol in tap water on Days 2–14 postpartum. Effects of genotype and neonatal treatment on offspring open‐field behavior, alcohol‐induced sleep time, and adrenocortical responsiveness to alcohol or saline injection were studied. The LS mice had higher ethanol‐induced sleep times than SS mice, and also higher plasma corticosterone levels following alcohol challenge. The LS mice also responded more to saline injection and to novelty stress, suggesting that they were generally more responsive to stressors than SS mice. Significant genotype‐dependent effects of neonatal treatment on (1) adrenocortical responsiveness to injection stress and (2) alcohol tolerance were noted. However, these 2 effects did not appear to be causally related. Neonatal treatment had no effect on open‐field activity or defecation in either

ISSN:0012-1630    

DOI:10.1002/dev.420120303

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractAdrenocortical responsiveness to separation in group‐living rhesus macaque mother‐infant pairs was determined. Cortisol evaluations were complemented by behavioral observations of mother‐infant interactions and group social behavior. Infants, but not their mothers, showed cortisol elevations that could be attributed specifically to separation. Steroid‐behavior relationships suggested that the infants of high dominant mothers evinced the greatest adrenocortical response to separation. These data exemplify the complexities involved in determining endocrine/behavior relationships in a group‐living

ISSN:0012-1630    

DOI:10.1002/dev.420120304

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractThree experiments examined the development of the acoustic startle reflex and its modification by a preliminary stimulus in the infant rat during the 2nd and 3rd postnatal weeks. The 1st experiment employed a white noise S1(20 msec, 70 dB), the 2nd a cutaneous S1(.5 msec, .5 mA and 1.0 mA shock), and the 3rd identical S1‐S2pairs (20 msec, 10 kHz, 110 dB tones). The results demonstrate a similar maturation of the prepulse modification pattern over days in the 3 experiments, evidenced mainly in the growth of inhibition. The findings indicate peripheral and central mechanisms that are maturing during the period of life under observation and that contribute to the developmental patterns of modificatio

ISSN:0012-1630    

DOI:10.1002/dev.420120305

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractThe effects of neonatal testosterone injections on adult male sexual behavior and plasma testosterone levels were investigated in several strains of male house mice. Both sexual behavior and plasma testosterone levels were increased in the testosterone‐treated groups from some strains, but the 2 variables did not change concomitantl

ISSN:0012-1630    

DOI:10.1002/dev.420120306

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractWe have examined the behavior of spontaneously hypertensive (SHR) rats and stroke‐prone hypertensive (SP‐SHR) male rats during the development and maintenance of elevated blood pressure and compared this pattern with age‐ and gender‐matched normotensive (WKY) rats of the same Wistar‐Kyoto strain as controls. Rats of each strain (n= 10/age group) were isolated in individual cages and observed for 60 min at 3,4,6,8,10, or 20 weeks of age using a scan sampling technique. At all ages SHR rats were significantly more active than WKY rats whereas SP‐SHR rats were intermediate in level of activity. In a 2nd series, activity of male rats of each strain was monitored continuously for 24 hr in the home cage. No strain differences in amount or pattern of total daily activity were evident at either 4–6 or 16–18 weeks of age. These results indicate that SHR rats are more reactive to environmental change, but the intermediate level of activity of SP‐SHR rats suggests that this response is not related to the degree of blood p

ISSN:0012-1630    

DOI:10.1002/dev.420120307

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractRat pups stunted by housing only 8 hr daily with lactating females and 16 hr with nonlactating foster mothers showed a delay in returning to their nest from other parts of the home cage. This delay was not due to changes in activity level or to lack of attraction to the nest, but appeared to be perceptual in nature. Both lactating and nonlactating females caring for stunted litters tended to be more maternal than those caring for control pups. After nutritional rehabilitation, the adult experimental animals showed no deficits in learning a series of visual discrimination problems in a modified version of the Lashley jumping stand procedure with a nonappetitive reinforcement. We compared the results with those obtained when other methods of stunting animals are employed and concluded that different methods of stunting may result in both common and divergent effects on behavior. Although many methods of stunting may produce similar behavioral deficits during the period of food deprivation, after rehabilitation behavioral deficits reported with other techniques of stunting may be due to extranutritional causes rather than to reduced food intake per se.

ISSN:0012-1630    

DOI:10.1002/dev.420120308

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractDaily maternal neck restraint, whole body restraint, hyperthermia, and ACTH treatment during the last 3rd of gestation had no reliable effect on open‐field and cage‐emergence behavior in male Sprague‐Dawley offspring. Many of these treatments, however, produced considerable maternal pathology and evidence for maternal adrenocorticoid release. Significant litter effects were found for almost every morphological and behavioral measure. Failure to control for the litter variable may account for many previously reported effects of prenatal stress on emotionality in rats. Female rats showed greater activity and less defecation than males on postpubertal open‐field and cage‐emerge

ISSN:0012-1630    

DOI:10.1002/dev.420120309

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractThe influence of the parental environment on the development of aggressive behaviors was studied in 2 muroid rodent species. Litters of southern grasshopper mice and northern white‐footed mice were reared by the natural parents or were reciprocally cross‐fostered soon after birth to parents of the opposite species. After weaning at 24–26 days, mice of both species were isolated and observed at 10‐day intervals from 30 to 100 days of age in one of the following tests: (1) predation on house crickets; (2) interspecific aggression toward Swiss‐Webster laboratory mice; and (3) intraspecific aggression toward opponents of the same gender and approximate age. Naturally reared grasshopper mice males and females displayed extremely high levels of aggressive and predatory behaviors whereas white‐footed mice controls were passive and defensive in all tests. Rearing by white‐footed mice foster parents resulted in a significant decrease in the aggression of grasshopper mice males and females toward laboratory mice. During intraspecific encounters, fostered grasshopper mice initiated fewer social interactions than naturally reared controls. The predatory behavior of grasshopper mice was not altered by the fostering procedure. The behavioral measures of fostered white‐footed mice showed no systematic changes when compared to controls. These results indicate that the postnatal parental environment contributes to the naturally high levels of aggressive behaviors of grasshopper mice. In contrast, the limited aggressive behaviors of a naturally passive species, white‐footed mice, were not increased by fostering at birth to parents of a highly aggressive species,

ISSN:0012-1630    

DOI:10.1002/dev.420120310

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

ISSN:0012-1630    

DOI:10.1002/dev.420120301

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY