Home Nest Research Articles

Appetitive instrumental training in preweanling rats: I. Motivational determinants.

Two experiments tested learning and retention of preweanling rats (10, 15, and 23 days of age) with an appetitive T-maze spatial discrimination task, using 3 different reinforcers for training (Mother Alone, Mother + Milk, and Milk Alone). The hypothesis was that immature rats are prepared to select and generate effective hypotheses for learning in an environment bearing some similarity to the home nest prior to their exhibiting similar capacities in other contexts. In Experiment I, we found support for this hypothesis in that 10- and 15-day-old rats were able to acquire the maze task when reinforced with Mother Alone or Mother + Milk, but not when reinforced with Milk Alone. In Experiment II, we report that 23-day-old rats weaned at 19 days postpartum were better at learning the maze task with milk as the reinforcer than littermates raised until training with the dam. We hypothesize that the development of foraging strategies might be necessary for the expression of maze behaviors reinforced with milk alone.

Wall climbing, odors from the home nest and catecholaminergic activity in rat pups

The present investigation examined the relationship among wall climbing, home nest odors, circadian rhythmicity and catecholaminergic activity. In the first experiment, a catecholaminergic agonist, amphetamine, was observed to induce wall climbing in 10- but not 15-day old rat pups. It was observed in the second experiment that an α-adrenergic antagonist, phentolamine, attenuated wall climbing elicited by foot shock in 10-day old rat pups without affecting general locomotor activity. However, haloperidol, a dopaminergic antagonist, was observed to decrease both shock-elicited wall climbing and general locomotor activity in rat pups at this age. These results support the hypothesis that wall climbing may be partially mediated by catecholaminergic activity. Home nest odors decreased both amphetamine-induced wall climbing for animals tested during the dark cycle in Experiment 1 and shock-induced wall climbing for subjects tested both during the light and dark phases in Experiment 2. This attenuation by home nest odors of both drug- and shock-elicited wall climbing suggests the further hypothesis that home nest odors may influence the level of catecholaminergic activity.

Repeated isolation experience during the preweanling period: Effects on behavioral ontogeny

Two experiments investigated the effects of repeated isolation of rat pups from the dam and conspecifics for 3 h daily commencing on the day following parturition and continuing until Postnatal Day 21. Sensorimotor development, nest-directed behavior (homing), and general activity were assessed during these 21 days. Results indicated that pups experiencing repeated isolation exhibited an earlier mature tail-hang and olfactory orientation response, somewhat more nest-directed behavior, and greater activity in an open field. These effects could be attenuated by isolating the rats with some aspect of the home nest environment, such as conspecifics or home nest litter.

Ontogenetic changes in the effectiveness of home nest odor as a conditioned stimulus

When odors from the home nest were paired with footshock, 12-day-old rat pups exhibited greater conditioned aversion to these odors than did 16-day-old pups. This superior performance of the younger animals was evident both at an immediate test and after retention intervals of 1 and 90 min if the subjects spent the conditioning-test delays in clean shavings. When the retention interval was spent in home shavings, only at an immediate test did the 12-day-olds display stronger aversions to the home nest odor than the 16-day-olds. Interjecting a conditioning-test delay of even 1 min in the home shavings dramatically disrupted the test performance of the younger pups.

Ontogeny of Ultrasonic and Locomotor Responses to Nest Odors in Rodents

SYNOPSIS. Rodents discriminate and prefer familiar odors early in life. Almost from birth young rats suckle in response to maternal odor, but suckle less when nipples are cleaned with organic solvents. In two-choice tests, young prefer familiar nest odors, whether naturally occurring or artificially presented, and can even be made to tolerate odors normally aversive or to avoid odors normally pleasant. Variations in maternal diet can alter odor preferences of theyoung. Nest odors can affect vocalization of young rodents. In contrast to the consistent effects of cold temperature and handling in the many rodents studied, nest odors may affect vocalization differently in different species. For example, familiar odors reduce calling in rats, but increase calling in pine voles. Nest odor also alters spontaneous activity in young rats, whichlocomote less when maternal odor is present. In this paper I report that home nest odors enhanced locomotion in rodents of three species (pine voles, Microtus pinetorum ; white-footed mice, Peromyscus leucopus ; and wild house mice, Mus musculus ), but that the age at which this pattern occurred and the relationships of nest odors to vocalizations differed among the species.

Adult responsiveness to ultrasonic signals from gerbils of varying ages: parity, gender, and housing effects.

Groups of adult gerbils differing by gender, parity, and presence or absence of young in the nest were exposed to taped ultrasonic distress calls of male and female pups on postnatal Days 3, 8, and 13. Frequency and time spent performing several behavioral items as well as frequency and time spent in the compartment housing the recorded tapes were assessed in the adult groups. Adult groups differed in rates and durations of certain behavioral items only during playback, with females with young in the home nest exhibiting the highest frequency of nest building in the test apparatus. However, all groups spent more time in the arm from which calls of Day-8 pups were played. Calls of Day-3 and Day-13 pups did not produce significant differences in adult responsiveness. These results reveal significant characteristics of the ultrasounds for each group which parallel certain morphological and behavioral changes.

The effects of increasing distance to food and deprivation level on food-hoarding behavior in Rattus norvegicus

Hooded rats, both deprived and not deprived of food, were allowed to hoard various sized food pellets from remote sites that varied in distance from a well-established home nest site. As the distance between the remote and home sites increased the deprived subjects hoarded larger sized food pellets. This trend was not as clear for nondeprived subjects. Increasing distance between the two sites was correlated with decreases in several measures of hoarding strength and with an increase in nonhoarding activities. At the greatest distance, less time was devoted to hoarding and less food was returned to the home site while exploratory and scent-marking activities increased in frequency. The data suggest that whereas food deprivation facilitates food hoarding, it is not a necessary condition for it. The implications of these data for optimal foraging strategies are discussed.

Experiential and hormonal conditions affect squab-egg choice in ring doves (Streptopelia risoria).

Noncycling, progesterone-injected, experienced male ring doves prefer eggs to squabs in a simultaneous squab-egg choice test, while experienced male doves injected with both progesterone and prolactin prefer squabs to eggs. When exogenous prolactin is administered to either naive or experienced male ring doves during the early phase of a normal incubation cycle, squab choice is significantly increased. Squab choice is also significantly increased in incubating doves by 24 hr of exposure to a squab in the home nest. This effect is greater in naive than in experienced doves. Squabs introduced during late incubation have more of a positive effect on squab choice than when introduced during early incubation. It is concluded that intracyclic experience organizes successive behavioral changes within a reproductive cycle and that naive doves are more affected by some changes in intracyclic events than are experienced doves.

Fact and Fiction in Natalie Savage Carlson's Autobiographical Stories: A Personal View

Fact and Fiction in Natalie Savage Carlson's Autobiographical StoriesA Personal View Julie Carlson McAlpine (bio) When I was sick in bed as a child, I was treated to nearly an hour of my mother's undivided attention before it was time for me to go to sleep each night. The choice of entertainment was always mine. Usually I would ask my mother, Natalie Savage Carlson, to "tell me about when you were a little girl, Mama." She often reminisced about life at "Shady Grove" and her Visitation Convent boarding school days. It was almost worth being sick to hear about stunt riding on circus horses, and I even felt as if I were the one who rescued her pet doves. Many years of publishing successful juvenile books about foreign places like Paris and sometimes fantastic characters like the bear Alphonse went by before my mother decided to draw on her own childhood for The Half Sisters (New York: Harper, 1970). It closes with the heroine Luvvy leaving the home nest to go to boarding school with her older half sisters. The inconclusive ending almost demanded its sequel, Luvvy and the Girls (New York: Harper, 1971). This is how my mother explains what finally inspired her to draw on her own background instead of seeking out new places and plots for her stories: Years ago when my editor at Harpers suggested that I write a book based on my childhood, I was completely uninterested. It was much more interesting to visit a colorful, out-of-the-way place and to write about the children I found there. Then, on a trip south, I made a detour to see what Time had done to "Shady Grove," my childhood home in Maryland. The large farmhouse showed a half-century of neglect. Black tar-paper covered the two wings, the green shutters were gone and so were many of the old trees whose shade had given the farm its name. The nearby village of Weverton was being scooped out for a freeway. The Chesapeake and Ohio Canal was only a weed-grown ditch with one of the wooden locks rotting into the ground. The railroad tracks that followed the canal were rusted. There was no trace of the blockhouses which had sheltered poor squatters. No one I contacted in Brunswick, the nearest "big town," knew that horse tournaments had once been held there. I was filled with nostalgia. If only I could bring back that beautiful, rugged region of western Maryland as it had been in the old days! I could and I did. I [End Page 157] wrote The Half Sisters and Luvvy and the Girls so a way of life gone forever wouldn't be forgotten. While the books provide an authentic picture of childhood in the colorful locale of Weverton, Maryland, during the early twenties, certain departures from strict factual reporting have necessarily taken place. For example, when my mother supplied the illustrator with snapshots of "Shady Grove" and Frederick Visitation Academy, he drew accurate backgrounds. But since she had no family pictures of that period to give him, Thomas di Grazia created a curly-haired family with a very Italian-looking Papa. My mother observes: "I have noticed that artists prefer to give their own pictorial interpretation to the characters I create." Although members of the Savage family may chuckle over their unaccustomed curls, readers, in any case, like artists, probably imagine the physical appearance of characters for themselves, no matter what they may look like in the mind of an author. Some changes from autobiographical fact, however, my mother introduced with a definite purpose in view. Luvvy's struggle in The Half Sisters is the aspiration of an eleven-year-old girl going on twelve to be grown up. Although she is the oldest of Papa's brood of children by his second wife, she does not wish to be associated with them. Rather, she desperately desires to be accepted by her older half sisters and to join them at boarding school. Actually, by constantly nagging her parents, my mother gained permission to go away to boarding school at the tender age of five. Her acceptance by...

Observations on the behavior of the Cerapachyine ants

Notes on the predatory behavior of species ofCerapachys, Phyracaces, andSphinctomyrmex are given. All of the species thus far studied have proven to be myrmecophagous, feeding on the brood (and in some cases adults) of other species of ants. Raids are conducted by groups of workers and are usually of short duration. A foraging expedition ofPhyracaces cohici is described, during which the workers started out as a compact group but later dispersed into small groups and lone individuals deployed in a circular pattern around the home nest. On the basis of these observations there is suggested a hypothetical pattern of alternating foraging and raiding behavior, which is believed to result ultimately in an efficient exploitation by the ants of the surrounding territory. Notes on other phases of biology, including colony size and nest structure, are given.