Scott Robinson - Academia.edu (original) (raw)
Papers by Scott Robinson
Developmental psychobiology, Apr 1, 2018
Previous research has revealed that fetuses detect and respond to extrauterine stimuli such as ma... more Previous research has revealed that fetuses detect and respond to extrauterine stimuli such as maternal movement and speech, but little attention has been cast on how fetuses may directly influence and respond to each other in the womb. This study investigated whether motor activity of E20 rat fetuses influenced the behavior of siblings in utero. Three experiments showed that; (a) contiguous siblings expressed a higher frequency of synchronized movement than noncontiguous siblings; (b) fetuses that lay between two siblings immobilized with curare showed less movement relative to fetuses between saline or uninjected controls; and (c) fetuses between two siblings behaviorally activated by the opioid agonist U50,488 also showed less activity and specific behavioral changes compared to controls. Our findings suggest that rat fetuses are directly impacted by sibling motor activity, and thus that a rudimentary form of communication between siblings may influence the development of fetuses...
Behavioral and Brain Sciences, Mar 1, 1989
Developmental Brain Research, Sep 1, 1992
Newborn rats exhibit a rich behavioral repertoire to access the nipple and obtain milk. In older ... more Newborn rats exhibit a rich behavioral repertoire to access the nipple and obtain milk. In older pups, catecholamines including dopamine (DA) mediate the behavioral effects of milk. In the present study, pups were delivered at term by caesarean section and instrumented with the microdialysis probe. Microdialysis samples were collected at 15 min intervals and K(+)-evoked levels of DA were measured with HPLC-ED. Pups received either no infusion, single or multiple intraoral infusions of saline or milk during subsequent samples. A decrease in K(+)-evoked DA release was evident after the first infusion in all subjects. Repeated milk infusions continued to reduce levels of extracellular DA, which remained evident 30 min after the last milk infusion. The rat neonate's first exposure to milk exerts lasting effects on neostriatal DA activity in the absence of prior suckling experience.
Explaining the emergence of behavioral organization and functional action patterns during ontogen... more Explaining the emergence of behavioral organization and functional action patterns during ontogeny represents a challenge for developmental science. Using interlimb coordination in the fetal and neonatal rat as a model behavior, this chapter reviews central mechanisms and sensory regulation of spontaneous limb movement, pharmacological induction of locomotor-like behavior, motor learning and memory, and environmental factors that contribute to the construction of organized motor behavior during perinatal development. Recent experiments indicate that action systems in the fetus emerge under the joint infl uence of neural resources, biomechanical constraints, proprioceptive feedback, and contingencies posed by the intrauterine environment. This research suggests that experience accruing from feedback about motor performance may play a signifi cant role in the perinatal construction of motor behavior.
Animal Behaviour, Dec 1, 1986
Using a preparation which allows in vivo observation, the spontaneous behaviour of rat fetuses wa... more Using a preparation which allows in vivo observation, the spontaneous behaviour of rat fetuses was recorded on successive days during the last third of gestation (days 16-21) in each of three microenvironments: In Uterus (viewed through the uterine wall), In Amnion (delivered outside the uterus and viewed through the intact amniotic membranes), and In Bath (removed from both uterus and amnion into a benign fluid medium with placental connection intact). These observations provide evidence that the rat fetus exhibits ontogenetic changes in behavioural repertoire, diversity and organization and is responsive to variations within its environment as development proceeds.
Behavioral Neuroscience, 1992
Developmental psychobiology, Jan 24, 2015
Adults primarily walk to reach a new location, but why do infants walk? Do infants, like adults, ... more Adults primarily walk to reach a new location, but why do infants walk? Do infants, like adults, walk to travel to a distant goal? We observed 30 13-month-old and 30 19-month-old infants during natural walking in a laboratory playroom. We characterized the bout structure of walking-when infants start and stop walking-to examine why infants start and stop walking. Locomotor activity was composed largely of brief spurts of walking. Half of 13-month-olds' bouts and 41% of 19-month-olds' bouts consisted of three or fewer steps-too few to carry infants to a distant goal. Most bouts ended in the middle of the floor, not at a recognizable goal. Survival analyses of the distribution of steps per bout indicated that the probability of continuing to walk was independent of the length of the ongoing bout; infants were just as likely to stop walking after five steps as after 50 steps and they showed no bias toward bouts long enough to carry them across the room to a goal. However, 13-mo...
American journal of obstetrics and gynecology, 1987
Transient compression of the umbilical cord has been implicated as a potential cause of unexplain... more Transient compression of the umbilical cord has been implicated as a potential cause of unexplained brain damage and/or fetal death. We induced acute fetal hypoxia by compressing the umbilical cord of the fetal rat with a microvascular clamp. Direct observation of fetal behavior immediately after cord compression identified a three-phase behavioral response to acute hypoxia, consisting of an initial suppression in motor activity, a brief period of hyperactivity, and a secondary suppression of movement. All three phases occurred in less than 2 minutes from the onset of hypoxia. The stereotypic hypoxic response of rat fetuses may be adaptive as a means of removing mechanical sources of umbilical cord compression. Among fetuses exposed to alcohol in utero, the response to hypoxia was diminished in intensity and duration. Because of their altered hypoxic response, alcohol-exposed fetuses may therefore be at greater risk from transient cord compression in utero.
The Quarterly journal of experimental psychology. B, Comparative and physiological psychology, 1992
Rat fetuses exhibit motor and cardiac responses to chemosensory stimulation on Days 20 and 21 of ... more Rat fetuses exhibit motor and cardiac responses to chemosensory stimulation on Days 20 and 21 of gestation. The first experiment demonstrated that fetuses exhibit an increase in overall motor activity and decrease in heartrate in response to an initial intraoral infusion of a lemon solution. After a series of nine exposures, however, fetuses no longer exhibit motor or cardiac responses to lemon infusion, suggesting the existence of a habituation-like process. Responsiveness recovers spontaneously following a 3- to 9-min period without stimulation. In a second experiment, a dishabituation treatment was administered to distinguish habituation, which is a centrally mediated decrement in response, from effector fatigue, sensory adaptation, and other peripheral mechanisms that can result in reduced responsiveness. A single infusion of mint following a series of nine lemon exposures was effective in reinstating fetal motor responses to lemon on both Days 20 and 21, but reinstated cardiac ...
Physiology & Behavior, 1986
A procedure enabling the direct endoscopic examination of rat fetuses in utero without the need f... more A procedure enabling the direct endoscopic examination of rat fetuses in utero without the need for surgical externalization of the uterus is described.
Physiology & Behavior, 1995
Rat fetuses exhibit prompt responses to an intraoral infusion of milk, including mouthing movemen... more Rat fetuses exhibit prompt responses to an intraoral infusion of milk, including mouthing movements and an increase in motor activity. Two experiments examined the involvement of dopamine D~ and D2 receptors in mediating these fetal responses to milk. The D~ agonist SKF-38393 and the D2 antagonist sulpiride diminished fetal mouthing responses. Mouthing responses appeared normal in fetuses treated with the D2 agonist quinpirole or the D~ antagonist SCH-23390. These findings suggest that activity in the dopamine system may inhibit mouthing within 30 s of milk infusion.
Developmental psychobiology, Jan 4, 2015
Fetal rats can alter patterns of interlimb coordination after experience with a yoke that links t... more Fetal rats can alter patterns of interlimb coordination after experience with a yoke that links two legs together. Yoke training results in a pronounced increase in conjugate limb movements (CLM). To determine whether yoke motor learning is mediated by spinal cord circuitry, fetal subjects at embryonic Day 20 (E20) received yoke training after mid-thoracic spinal cord transection or sham surgery. Both spinal and sham-treated fetuses exhibited an increase in CLM during training. In a second experiment, fetuses received initial yoke training, then were transected or sham treated before a 2nd training. Spinal and sham fetuses that were yoked during both training sessions exhibited a more rapid rise in CLM than those yoked only in the later session. These findings indicate that motor learning in fetal rats can be supported by spinal cord circuitry alone, and that savings implies a form of motor memory localized in the spinal cord. © 2015 Wiley Periodicals, Inc. Dev Psychobiol.
Physiology & Behavior, 1991
Resting heart rate (HR) and HR responses of fetal and neonatal rats are described before and afte... more Resting heart rate (HR) and HR responses of fetal and neonatal rats are described before and after intraoral infusion of isotonic saline or lemon solution. Stable measurements of resting HR were obtained for fetuses over the last three days of gestation (El9, E20, E21) and pups on the day of birth (P0) and four subsequent postnatal ages (P1, P3, P5, P7). Resting HR decreased significantly on P0 relative to the three prenatal ages and exhibited a linear increase thereafter. Variability in resting HR was pronounced on E21, decreased sharply after birth, and gradually increased through P7. Developmental changes in the HR response of fetuses and pups were evident following infusion of lemon. Fetal HR responses to lemon were characterized by bradycardia, which increased in magnitude through P1, diminished after P1, and eventually changed to tachycardia by P7. Both resting HR and HR responses to chemosensory stimulation point to the immediate perinatal period as a time of quantitative and qualitative change during sensory development.
Physiology & Behavior, 1986
A technique is described whereby lidocaine with epinephrine is injected into the spinal cord of t... more A technique is described whereby lidocaine with epinephrine is injected into the spinal cord of the pregnant rat to produce reversible spinal anesthesia. This technique is useful for preparing pregnant females to study the spontaneous behavior of their fetuses in utero. Comparison of this procedure with an alternative, but irreversible, spinal preparation (chemomyelotomy) indicates that reversible lidocaine anesthesia does not differentially influence the activity of rat fetuses on Day 19 of gestation. This procedure will enable repeated observation of the same fetus at various stages of gestation and provide a means for the longitudinal study of behavioral development across the transition from prenatal to postnatal life.
Developmental psychobiology, Apr 1, 2018
Previous research has revealed that fetuses detect and respond to extrauterine stimuli such as ma... more Previous research has revealed that fetuses detect and respond to extrauterine stimuli such as maternal movement and speech, but little attention has been cast on how fetuses may directly influence and respond to each other in the womb. This study investigated whether motor activity of E20 rat fetuses influenced the behavior of siblings in utero. Three experiments showed that; (a) contiguous siblings expressed a higher frequency of synchronized movement than noncontiguous siblings; (b) fetuses that lay between two siblings immobilized with curare showed less movement relative to fetuses between saline or uninjected controls; and (c) fetuses between two siblings behaviorally activated by the opioid agonist U50,488 also showed less activity and specific behavioral changes compared to controls. Our findings suggest that rat fetuses are directly impacted by sibling motor activity, and thus that a rudimentary form of communication between siblings may influence the development of fetuses...
Behavioral and Brain Sciences, Mar 1, 1989
Developmental Brain Research, Sep 1, 1992
Newborn rats exhibit a rich behavioral repertoire to access the nipple and obtain milk. In older ... more Newborn rats exhibit a rich behavioral repertoire to access the nipple and obtain milk. In older pups, catecholamines including dopamine (DA) mediate the behavioral effects of milk. In the present study, pups were delivered at term by caesarean section and instrumented with the microdialysis probe. Microdialysis samples were collected at 15 min intervals and K(+)-evoked levels of DA were measured with HPLC-ED. Pups received either no infusion, single or multiple intraoral infusions of saline or milk during subsequent samples. A decrease in K(+)-evoked DA release was evident after the first infusion in all subjects. Repeated milk infusions continued to reduce levels of extracellular DA, which remained evident 30 min after the last milk infusion. The rat neonate's first exposure to milk exerts lasting effects on neostriatal DA activity in the absence of prior suckling experience.
Explaining the emergence of behavioral organization and functional action patterns during ontogen... more Explaining the emergence of behavioral organization and functional action patterns during ontogeny represents a challenge for developmental science. Using interlimb coordination in the fetal and neonatal rat as a model behavior, this chapter reviews central mechanisms and sensory regulation of spontaneous limb movement, pharmacological induction of locomotor-like behavior, motor learning and memory, and environmental factors that contribute to the construction of organized motor behavior during perinatal development. Recent experiments indicate that action systems in the fetus emerge under the joint infl uence of neural resources, biomechanical constraints, proprioceptive feedback, and contingencies posed by the intrauterine environment. This research suggests that experience accruing from feedback about motor performance may play a signifi cant role in the perinatal construction of motor behavior.
Animal Behaviour, Dec 1, 1986
Using a preparation which allows in vivo observation, the spontaneous behaviour of rat fetuses wa... more Using a preparation which allows in vivo observation, the spontaneous behaviour of rat fetuses was recorded on successive days during the last third of gestation (days 16-21) in each of three microenvironments: In Uterus (viewed through the uterine wall), In Amnion (delivered outside the uterus and viewed through the intact amniotic membranes), and In Bath (removed from both uterus and amnion into a benign fluid medium with placental connection intact). These observations provide evidence that the rat fetus exhibits ontogenetic changes in behavioural repertoire, diversity and organization and is responsive to variations within its environment as development proceeds.
Behavioral Neuroscience, 1992
Developmental psychobiology, Jan 24, 2015
Adults primarily walk to reach a new location, but why do infants walk? Do infants, like adults, ... more Adults primarily walk to reach a new location, but why do infants walk? Do infants, like adults, walk to travel to a distant goal? We observed 30 13-month-old and 30 19-month-old infants during natural walking in a laboratory playroom. We characterized the bout structure of walking-when infants start and stop walking-to examine why infants start and stop walking. Locomotor activity was composed largely of brief spurts of walking. Half of 13-month-olds' bouts and 41% of 19-month-olds' bouts consisted of three or fewer steps-too few to carry infants to a distant goal. Most bouts ended in the middle of the floor, not at a recognizable goal. Survival analyses of the distribution of steps per bout indicated that the probability of continuing to walk was independent of the length of the ongoing bout; infants were just as likely to stop walking after five steps as after 50 steps and they showed no bias toward bouts long enough to carry them across the room to a goal. However, 13-mo...
American journal of obstetrics and gynecology, 1987
Transient compression of the umbilical cord has been implicated as a potential cause of unexplain... more Transient compression of the umbilical cord has been implicated as a potential cause of unexplained brain damage and/or fetal death. We induced acute fetal hypoxia by compressing the umbilical cord of the fetal rat with a microvascular clamp. Direct observation of fetal behavior immediately after cord compression identified a three-phase behavioral response to acute hypoxia, consisting of an initial suppression in motor activity, a brief period of hyperactivity, and a secondary suppression of movement. All three phases occurred in less than 2 minutes from the onset of hypoxia. The stereotypic hypoxic response of rat fetuses may be adaptive as a means of removing mechanical sources of umbilical cord compression. Among fetuses exposed to alcohol in utero, the response to hypoxia was diminished in intensity and duration. Because of their altered hypoxic response, alcohol-exposed fetuses may therefore be at greater risk from transient cord compression in utero.
The Quarterly journal of experimental psychology. B, Comparative and physiological psychology, 1992
Rat fetuses exhibit motor and cardiac responses to chemosensory stimulation on Days 20 and 21 of ... more Rat fetuses exhibit motor and cardiac responses to chemosensory stimulation on Days 20 and 21 of gestation. The first experiment demonstrated that fetuses exhibit an increase in overall motor activity and decrease in heartrate in response to an initial intraoral infusion of a lemon solution. After a series of nine exposures, however, fetuses no longer exhibit motor or cardiac responses to lemon infusion, suggesting the existence of a habituation-like process. Responsiveness recovers spontaneously following a 3- to 9-min period without stimulation. In a second experiment, a dishabituation treatment was administered to distinguish habituation, which is a centrally mediated decrement in response, from effector fatigue, sensory adaptation, and other peripheral mechanisms that can result in reduced responsiveness. A single infusion of mint following a series of nine lemon exposures was effective in reinstating fetal motor responses to lemon on both Days 20 and 21, but reinstated cardiac ...
Physiology & Behavior, 1986
A procedure enabling the direct endoscopic examination of rat fetuses in utero without the need f... more A procedure enabling the direct endoscopic examination of rat fetuses in utero without the need for surgical externalization of the uterus is described.
Physiology & Behavior, 1995
Rat fetuses exhibit prompt responses to an intraoral infusion of milk, including mouthing movemen... more Rat fetuses exhibit prompt responses to an intraoral infusion of milk, including mouthing movements and an increase in motor activity. Two experiments examined the involvement of dopamine D~ and D2 receptors in mediating these fetal responses to milk. The D~ agonist SKF-38393 and the D2 antagonist sulpiride diminished fetal mouthing responses. Mouthing responses appeared normal in fetuses treated with the D2 agonist quinpirole or the D~ antagonist SCH-23390. These findings suggest that activity in the dopamine system may inhibit mouthing within 30 s of milk infusion.
Developmental psychobiology, Jan 4, 2015
Fetal rats can alter patterns of interlimb coordination after experience with a yoke that links t... more Fetal rats can alter patterns of interlimb coordination after experience with a yoke that links two legs together. Yoke training results in a pronounced increase in conjugate limb movements (CLM). To determine whether yoke motor learning is mediated by spinal cord circuitry, fetal subjects at embryonic Day 20 (E20) received yoke training after mid-thoracic spinal cord transection or sham surgery. Both spinal and sham-treated fetuses exhibited an increase in CLM during training. In a second experiment, fetuses received initial yoke training, then were transected or sham treated before a 2nd training. Spinal and sham fetuses that were yoked during both training sessions exhibited a more rapid rise in CLM than those yoked only in the later session. These findings indicate that motor learning in fetal rats can be supported by spinal cord circuitry alone, and that savings implies a form of motor memory localized in the spinal cord. © 2015 Wiley Periodicals, Inc. Dev Psychobiol.
Physiology & Behavior, 1991
Resting heart rate (HR) and HR responses of fetal and neonatal rats are described before and afte... more Resting heart rate (HR) and HR responses of fetal and neonatal rats are described before and after intraoral infusion of isotonic saline or lemon solution. Stable measurements of resting HR were obtained for fetuses over the last three days of gestation (El9, E20, E21) and pups on the day of birth (P0) and four subsequent postnatal ages (P1, P3, P5, P7). Resting HR decreased significantly on P0 relative to the three prenatal ages and exhibited a linear increase thereafter. Variability in resting HR was pronounced on E21, decreased sharply after birth, and gradually increased through P7. Developmental changes in the HR response of fetuses and pups were evident following infusion of lemon. Fetal HR responses to lemon were characterized by bradycardia, which increased in magnitude through P1, diminished after P1, and eventually changed to tachycardia by P7. Both resting HR and HR responses to chemosensory stimulation point to the immediate perinatal period as a time of quantitative and qualitative change during sensory development.
Physiology & Behavior, 1986
A technique is described whereby lidocaine with epinephrine is injected into the spinal cord of t... more A technique is described whereby lidocaine with epinephrine is injected into the spinal cord of the pregnant rat to produce reversible spinal anesthesia. This technique is useful for preparing pregnant females to study the spontaneous behavior of their fetuses in utero. Comparison of this procedure with an alternative, but irreversible, spinal preparation (chemomyelotomy) indicates that reversible lidocaine anesthesia does not differentially influence the activity of rat fetuses on Day 19 of gestation. This procedure will enable repeated observation of the same fetus at various stages of gestation and provide a means for the longitudinal study of behavioral development across the transition from prenatal to postnatal life.