Hypothermic vocalizations of rat pups (Rattus norvegicus) and direct maternal search behavior.

Emissions of ultrasonic vocalizations (USVs) by rat pups (Rattus norvegicus) during hypothermia have consequences for recovery and warming. The effects on dam behavior of USVs emitted by 3- to 11-day-old pups during hypothermia at rectal temperatures between 18 and 22°C was investigated Rat dams were tested in a Y maze with the home cage as a start box. Dams were given, in one condition, a choice between a hypothermic pup emitting USVs or a hypothermic, silent (anesthetized) pup and, in the other, a choice between 2 hypothermic, silent pups. Although differing in some acoustic properties from normal isolation calls, USVs emitted by hypothermic pups both elicited maternal search behavior and acted as directional cues for dams, in comparisons with control dams exposed only to silent pups. Thus USVs of pups recovering from extreme hypothermia have communicative as well as physiological significance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Maternally modulated infant separation responses are regulated by D2-family dopamine receptors.

Although dopamine is necessary for mammalian adult pair-bond formation and maternal behavior, its function in infant social behavior and attachment has been less thoroughly explored. The vocalization rate of an isolated rat pup is influenced by recent social contact. Interactions with the dam potentiate vocalization rate. Interactions with littermates or adult males do not. Systemic administration of the D2-family agonist quinpirole specifically blocked maternal potentiation at doses that did not alter vocalization rate in an isolation prior to dam contact. This result was not explained by quinpirole's effects on body temperature or locomotion. The results are consistent with a role for dopamine in infant social behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Potentiation of isolation-induced vocalization by brief exposure of rat pups to maternal cues

Since their discovery in 1956, the highest rates of ultrasonic vocalization (USV) have been recorded from infant rats when first isolated in an unfamiliar place. We now report that peak USV rates can be doubled by allowing test pups a brief initial period of contact with their anesthetized dam (1-10 min) in the test chamber before isolating the pup by her removal. Potentiation of the isolation response was specific to the dam, for it failed to occur following initial contact with a group of 4 warm, anesthetized littermates. Control experiments showed that potentiation could not be attributed to thermal contrast, experimenter handling, general behavioral activation, novelty of maternal cues, or nursing deprivation. Furthermore, it did not occur when pups were taken for isolation testing directly from prolonged contact with their anesthetized dam in the home cage. Potentiation may be understood in terms of the communicative role of the pups' call and/or prior learning contingencies within the mother-infant interaction.     

Ultrasonic vocalization, laryngeal braking, and thermogenesis in rat pups: A reappraisal.

Tested the hypothesis that the respiratory events underlying rat pup ultrasonic vocalization (USV) facilitate brown adipose tissue (BAT) thermogenesis, as proposed by M. S. Blumberg and J. R. Alberts (1990). Laryngeal denervation of tracheostomy were used to reduce or eliminate laryngeal braking and prevent USV in 9- to 10-day-old pups during recovery from deep hypothermia and during cooling induced by isolation for 1 hr at room temperature. Both forms of devocalization slowed rewarming of hypothermic pups, but neither had any effects on cooling rate or BAT thermogenesis in normothermic pups that were allowed to cool from 35°C to 29°C. Physiological effects of laryngeal braking on thermogenesis appear to be limited to conditions, such as severe hypothermia, in which ventilatory and oxygen transport functions are compromised. Results have implications for understanding the regulation and evolution of USV. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Brief Maternal Interaction Increases Number, Amplitude, and Bout Size of Isolation-Induced Ultrasonic Vocalizations in Infant Rats (Rattus norvegicus).

The number, amplitude, duration, and bout structure of isolation-induced ultrasonic vocalization (USV) of infant rats (Rattus norvegicus) were measured on postnatal Day 10. Measurements were made before and after a brief, 1-min, active interaction with their mother or before and after a "pick-up" control procedure. Consistent with prior studies, the number of USVs emitted was significantly increased in the period following the maternal reunion but not after the control procedure. The average amplitude of USVs was also greater following maternal reunion. Finally, analyses characterizing the bout structure of USV production indicated that the average bout size (i.e.. number of USVs/bout) was increased severalfold following the reunion with the mother, accounting for the greater rate of USV production during the second isolation period. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Examination of optimum benefits of customer and LSE by incentive and dynamic price-based demand response

ABSTRACT

The balancing approach of electricity generation and consumption is an essential part of a reliable power system. The mismatch between supply and demand may also cause fluctuation in the power system. This study proposes an incentive and penalty-based demand response (I&P-DR) program for improving the profitability of both LSE and customers. First, we use a parameter that weighs the financial benefits of LSE and customers and provides considerable economic benefits to both sides. Second, an incentive and penalty (I&P) price scheme have been employed to recompense and penalize customers and reduce the electricity demand at peak hours. Finally, the study analyzes the importance of (I&P-DR) and its impact on customers’ sensitivity during peak intervals. Simulation results showed that the flexibility to consumption can be brought through the application of the proposed (I&P-DR) program and also provide the financial benefits to both, customers and LSEs.     

Maternal interactions prior to separation potentiate isolation-induced calling in rat pups.

The vocal response rates of 12–13 day old infant rats to isolation in a bare test box are markedly increased by brief (1-min) periods of contact with an anesthetized dam prior to isolation, without affecting other isolation-induced behaviors. No such potentiation followed brief contact with littermates, novel test conditions, or experimenter handling. Brief contact with the dam was equally effective in the test chamber or home cage and was not further enhanced by repeated contact-separation sequences. Passive contact became ineffective when prolonged to 30 min, and potentiation could not be restored by providing the additional reinforcing events of continuous suckling, periodic oxytocin-induced milk letdown, or bouts of simulated maternal licking. However, when pups engaged in active interaction with an awake dam, potentiation was significantly enhanced following 1-, 10-, and 30-min periods. A working hypothesis is outlined for the adaptive role of potentiation in the development of the rat pup. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Suckling in the rat: Evidence for patterned behavior during sleep.

Electrophysiological recordings showed that 6 2-wk-old Wistar rat pups were actually asleep 66% of the time while suckling on the dam. Ss were no more likely to be awake while on the nipple than between nursing bouts. EMG-recorded sucking behavior occurred during sleep as well as during wakefulness. Ss were found to be asleep just prior to the dam's periodic milk ejections (ME) in 100% of 33 recorded instances and were briefly awakened by the ME, but 60% were asleep again within 30 sec. These studies demonstrate the embedding of a vital early behavior pattern in the states of sleep. (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)