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Biomedical subjects

J M Stern

Publications and source records attributed to J M Stern.

At least 55 records · Page 3Linked to original sources

Trigeminal lesions and maternal behavior in Norway rats: I. Effects of cutaneous rostral snout denervation on maintenance of nurturance and maternal aggression.

Cutaneous desensitization of the upper, rostral snout by bilateral section of the infraorbital nerves in lactating Norway rat dams markedly, but transiently, disrupted retrieval and licking of pups, nursing behavior, and fighting with a strange male intruder. Removal of the mystacial vibrissae, which provide major inputs to the infraorbital nerves, or cutaneous desensitization of the chin by bilateral sectioning of the mental nerves did not disrupt these behaviors. However, cutaneous desensitization of both the upper and lower rostral snout exacerbated and prolonged the effects produced by infraorbital denervation alone. The control of maternal behavior and aggression by somatosensory reflexes and the possible bases for rapid behavioral recovery after partial trigeminal sensory denervations are discussed.

Aggression↗

Ventral somatosensory determinants of nursing behavior in Norway rats. I. Effects of variations in the quality and quantity of pup stimuli.

By varying the quality and quantity of tactile input that rat dams, between Days 2 and 14 postpartum, received from their pups, we found the following: a) After a 4-hr separation from their litter, mothers continuously display an array of activities, until the onset of nursing, in response to displaced pups and to pups gathered in the nest. b) While the dam hovers over the gathered pups, engaged in an activity such as pup-licking, the young gain access to the dam's ventrum and root for a nipple. c) Pups capable of effective rooting, nipple attachment, and suckling thereby stimulate the dam's immobility (i.e., inhibition of head and limb movements), assumption of the upright crouching posture, and milk ejections. d) Rat dams do not become immobile or crouch in response to pups that are inactive or that are active but incapable of rooting effectively or suckling. e) The likelihood and speed of assuming the quiescent nursing posture, as well as of having milk ejections subsequently, are directly related to the number of effective pups in the nest. We propose that the initiation, maintenance and termination of nursing behavior are related to the spatial and temporal summation of effective ventral somatosensory afferents.

Animals↗

Multisensory regulation of maternal behavior and masculine sexual behavior: a revised view.

Frank Beach's view of the multisensory regulation in Norway rats of copulation in males (12) and of pup retrieval in females (23) is critically analyzed and revised in terms of Lashley's influence, Beach's other work, and current neurobiological knowledge. Beach's view was that no single sensory stimulus is essential to elicit these behaviors, but that all relevant stimuli available summate in the neocortex; consequently, (a) sexual "arousal" is increased in males, leading to copulation, and (b) the "efficiency," or likelihood, of retrieval is increased in postpartum mothers. The revised view is based on a component analysis in which each of these behaviors consists of a chain of motoric responses elicited by somatosensory stimulation. Distal stimuli emanating from the female or pups induce proximity by provoking orientation, attention and arousal; the meaning of these stimuli is largely learned by conditioned associations during the initial executions of the behavior, although odors may have a prepotent influence for some individuals. Stimuli are integrated in a multisensory manner by both subcortical and neocortical mechanisms. Generalizations concerning the reproductive behavior of other mammalian species are suggested.

Animals↗

Maternal aggression: disruption by perioral anesthesia in lactating Long-Evans rats (Rattus norvegicus).

Role of perioral somatosensation in the display of maternal aggression in Long-Evans Norway rats (Rattus norvegicus) was investigated during early lactation by local anesthesia of the mystacial pads with lidocaine, which blocks conduction in the infraorbital nerve. Acute perioral anesthesia markedly reduced the likelihood that maternal aggression was expressed; this effect of perioral anesthesia was not ameliorated by a repeated test with the same treatment or by pretreatment fighting experience. The dams that fought with the intruder during perioral anesthesia did so after greatly increased sniffing contact and with decreased vigor compared with controls. Males that were attacked tended to freeze, whereas males that were not attacked were active. Thus, trigeminal afferents are critical for the initiation and normal execution of maternal aggression responses in Norway rats.

Aggression↗

Prolactin circadian rhythm persists throughout lactation in women.

To determine whether the prolactin (PRL) circadian rhythm, with its characteristic nocturnal rise, persists during the hyperprolactinemia of lactation, PRL levels were analyzed in blood samples collected hourly for 24 h from 20 mothers, 4-46 months postpartum. The circadian rhythm of PRL persisted throughout lactation as manifested by: (1) significantly higher mean nighttime than daytime PRL levels in the whole sample, despite higher daytime nursing durations; (2) the distribution of zenith levels which most frequently occur between 23.00 and 07.00 h, when nursing duration is lowest, and which are almost absent between 07.00 and 23.00 h, when nursing duration is highest, and of nadir levels, which have an opposite pattern; (3) spontaneous PRL surges that are more frequent, longer, and of higher magnitude at night than during the day, and (4) the larger magnitude of suckling-induced PRL release from late afternoon through the night compared to the morning in some women. Our data suggest that the mechanisms responsible for the circadian rhythm in PRL secretion are relatively independent of the mechanisms of suckling-induced release. We propose that the nocturnal rise in PRL during lactation functions to ensure a robust milk supply during an extensive nonsuckling interval.

Circadian Rhythm↗

Prevalence of nutrition-related problems among long-term survivors of allogeneic marrow transplantation.

The nutritional status and prevalence of nutrition-related problems in 192 adult and child allogeneic marrow transplant recipients were evaluated 1 year after transplant in a retrospective chart review. Among these patients, 63% exhibited evidence of chronic graft-versus-host disease (GVHD) at the time of nutrition evaluation, including 44% with extensive disease who were receiving immunosuppressive therapy. Oral sensitivity was observed in 23% of all patients reviewed, and frank stomatitis occurred in 8%. The frequency of xerostomia was 18%; anorexia, 8%; reflux symptoms, 7%; diarrhea, 7%; steatorrhea, 5%; dysgeusia, 3%; and limited exercise tolerance because of dyspnea or joint contractures, 4%. Weight loss 3 to 12 months after transplant was experienced by 28%. Nutrition-related problems, changes in anthropometric indexes indicative of suboptimal nutritional status, and inadequate energy intake were observed more frequently in patients with extensive chronic GVHD than in patients without GVHD or in those with limited GVHD. Our findings indicate a high prevalence of nutrition problems among recipients of allogeneic marrow transplantation 1 year after transplant and, further, suggest the need for ongoing, community-based nutrition monitoring after discharge from a transplant center.

Adult↗

Ovarian hormone-induced short-latency maternal behavior in ovariectomized virgin Long-Evans rats.

Two ovarian hormone regimens reported to induce rapid-onset maternal behavior (MB) in maternally naive virgin, ovariectomized Sprague-Dawley (SD) albino rats (R. S. Bridges, 1984, Endocrinology 114, 930-940; A. L. Giordano, 1987, Doctoral Dissertation, Rutgers University, Newark, NJ) were assessed in Long-Evans (LE) hooded rats, a strain which tends to be less maternally responsive in various situations dissociated from parturition. The combination of sufficiently high and long-lasting treatments with estradiol (E, 10-mm Silastic capsule, sc, on Day 1) and progesterone (P, 3 x 30-mm Silastic capsules, Days 3-13) resulted in a mean MB onset latency (after pup presentation on Day 14) of 1.8 days. In contrast, no-hormone or P-only controls had latencies of about 5.5 days. However, the E + P combination was completely ineffective if the E capsule was withdrawn along with the P capsules, unlike the case for SD rats. Also in contrast to the albinos, E alone was ineffective, while E treatment following P withdrawal was only partially effective. The most efficacious regimen, which included a P treatment (injections of 4 mg/day, Days 3-12 or 3-15) known to maintain pregnancy in ovariectomized rats, resulted in mean latencies of less than or equal to 1 day; 39% overall displayed MB rapidly, i.e., retrieval within 15 min of exposure to pups and crouching by 3 hr, and 89% became maternal by the next day. With this regimen, neither duration of 4 mg/day P treatment (10 or 13 days) nor hysterectomy 2 days before testing affected MB latencies. Thus, the essential features of the previously reported ovarian hormone regimens for induction of short-latency MB are efficacious in LE rats, but the hormonal requirements in this strain seem to be more precise. Factors which might contribute to an even higher percentage maternal on the first day of pup exposure are considered.

Animals↗

Perioral anesthesia disrupts maternal behavior during early lactation in Long-Evans rats.

The role of perioral somatosensory stimulation from pups in maternal behavior was investigated in lactating Long-Evans rats (Rattus norvegicus) during early lactation by local anesthesia of the mystacial pads with lidocaine, which blocks conduction in the infraorbital nerve. It was concluded that (1) acute perioral anesthesia markedly inhibited pup retrieval when the subjects had no formal pretreatment retrieval experience. Further, these dams displayed little tolerance to the lidocaine treatment when they were tested repeatedly. (2) The severity of the effects of perioral anesthesia on retrieval was dependent upon prior experience and the testing situation. Following pretreatment retrieval experience, and in a test cage with dark and light compartments which provided a strong incentive to retrieve, 80% of lidocaine-injected dams did retrieve. However, retrieval efficiency was impaired by perioral anesthesia, largely due to increased time in contact with pups prior to each retrieval and to increased carrying time. (3) Perioral anesthesia also inhibited pup licking, but not self-grooming, suggesting that the former, but not the latter, is largely under peripheral stimulus control and that deficits in maternal oral activities cannot be due to impairment of mouth opening and use. (4) The onset of nursing behavior was delayed until after the recovery of snout sensations and retrieval. This suggests that a maternal behavior not directly involving the mouth is nonetheless dependent upon the dam's receipt of perioral tactile input from pups.

Anesthesia, Local↗

Perioral somatosensory determinants of nursing behavior in Norway rats (Rattus norvegicus).

Prior to assuming the upright crouching posture over their pups during nursing bouts, lactating rats typically engage in several oral behaviors, including nuzzling, licking and rearranging pups. By acutely depriving dams of various aspects of perioral stimulation from pups (with anesthesia of the mystacial pads or of the tongue, with mouth suturing, or with muzzling), we found the following: (1) Distal stimulation from pups maintains proximity-seeking behavior, but is insufficient to stimulate nursing behavior. (2) Lack of tongue feedback decreases pup licking and hastens the onset of crouching. (3) Snout, but not tongue, contact with pups is required for hovering over them. (4) The position of the dam while hovering over her litter enables the pups to gain access to her ventrum, thereby provoking her upright, crouching posture. (5) Older pups are capable of bypassing the dam's perioral attentions and stimulating crouching directly by burrowing under the dam's ventrum.

Animals↗

Experience with younger siblings facilitates maternal responsiveness in pubertal Norway rats.

The latency of maternal behavior (MB) onset induced by cohabitation with pups (sensitization) increases in female and male Long-Evans rats from 24 days of age (1-2 day latency) to 42 days of age (4-5 day latency). This decline in maternal responsiveness at Day 42 did not occur in 50% of rats ("responders") which lived with their dam and younger siblings (conceived during the postpartum estrus) for either 4 or 11-18 days after their birth. In contrast to cessation of suckling at about Day 25 postpartum in the absence of a 2nd litter, when a 2nd litter was born greater than Day 26 or less than Day 26 postpartum, suckling continued for a mean of 32 and 35.5 days, respectively (and up to Day 40). Also, time spent suckling during the 10 days following the birth of the 2nd litter was more than five times as great if the 2nd litter was born with little or no delay (less than Day 26). The offspring from the 1st litter spent about 80% of the diurnal observation time in proximity to the dam and younger siblings, and instances of nurturance (retrieving, crouching, licking) toward the young littermates were observed. However, the only dam-litter interaction significantly related to subsequent maternal responsiveness by 1st litter offspring was a positive relation between the prior incidence of aggression by mothers towards juveniles and sensitization latency.

Animals↗

Pubertal decline in maternal responsiveness in Long-Evans rats: maturational influences.

Latency to onset of maternal behavior increases progressively from the weanling to the peripubertal period in female and male Long-Evans rats. Gonadectomy or hypophysectomy on day 21 had no influence on the pubertal decline in maternal responsiveness. Apparently, inhibitory neural pathways mature which are independent of pituitary hormonal influences.

Animals↗

Nursing behaviour, prolactin and postpartum amenorrhoea during prolonged lactation in American and !Kung mothers.

In order to determine the effects of protracted nursing in American women, blood was collected hourly for 24 h and nursing periods recorded in 20 mothers, 10 amenorrhoeic, 3 3/4 to 17 1/4 months postpartum (PP), and 10 menstruating, 5 1/4 to 46 months PP. These data were compared to the daytime nursing behaviour and 1000-1100 h PRL of women among !Kung hunter-gatherers of Botswana, a non-contraceptive using population with a birth space interval of greater than 3 years. Intense nursing behaviour maintained amenorrhoea and hyperprolactinaemia for 1 to nearly 2 years PP in both American and !Kung mothers. Among Americans, 80 min of nursing per day, in conjunction with a minimum of six nursing episodes, was highly predictive of remaining amenorrhoeic up to 18 months PP. Amenorrhoea was always accompanied by hyperprolactinaemia, but delay in the onset of menses was related more to nursing behaviour than to a particular 24 h PRL level. The 1000-1100 h sample is equivalent to and about half of the 24 h mean in high and low intensity nursers, respectively. The !Kung women were similar to the high intensity nursing American women in 1000-1100 h PRL, percent amenorrhoeic, and the number of minutes of daytime nursing.

Adult↗

Parturition influences initial pup preferences at later onset of maternal behavior in primiparous rats.

Initial maternal responsiveness as a function of varying pup stimuli was assessed in primiparous Long-Evans rats. Pups were removed during parturition and the dams tested beginning 24 hr later. These dams were most likely to respond maternally towards newborn (0-2-day-old) rat pups (100%) and 6-8-day-old hamsters, which are the size of newborn rats (83.3%). In contrast, dams were significantly less likely to respond maternally towards newborn hamsters (50%) and 8-10-day-old rats (16.7%), pups which are half as large and twice as large, respectively, as newborn rats; indeed, dams were likely to attack these pups (33.3% and 25%, respectively). The maternal response (less than or equal to 1 hr) to dead newborn rats was similar to that towards live newborn rats, except that fewer dams retrieved dead pups rapidly (less than or equal to 1 min). Cesarean-delivered dams did not display higher maternal responsiveness towards 0-2 than towards 8-10-day-old rats. Further, whereas no parturition-experienced dam displayed infanticide towards newborn rats, 21.9% of primiparous Cesarean-delivered dams did. Thus, the exogenous and/or endogenous stimuli associated with parturition enhance selective maternal responsiveness and diminish infanticide towards pups the size of newborn rats.

Aggression↗

Neuropsychological outcome during late stage of recovery from brain injury: a proposal.

The neuropsychological outcome of Cranio-Cerebral Injury changes with time. This change may be best regarded as a specific effect/general effects ratio which lowers over time. The specific effects refer to disorders of information, recognition and symbolization. The present paper describes the general effects of brain injury. We will describe the lowered capacity of the cognitive system, which results in disorders of different aspects of concept formation and utilization (i.e. disorders of information processing).

Brain Injuries↗

The Rey-Osterrieth Complex as a diagnostic measure of neuropsychological outcome of brain injury.

The Rey-Osterrieth Complex was devised to investigate perceptual organization and visual memory in brain-damaged patients. Osterrieth analyzed the patient's method of procedure as well as his specific copying errors, but the test is most commonly regarded as a measure of visual memory. In our work with traumatically brain-injured patients we found the Rey-Osterrieth Complex useful as a high load examiner of disorders of cognitive process. In our application of the test the drawing quality in the copy session is seen as being related to the kind of disorder, while the neuropsychological deficit is emphasized by the drawing quality in the memory session. The present paper is concerned with different thinking disorders as they are expressed in both the copy and memory parts of the Rey-Osterrieth Complex.

Adult↗

Behavioral disturbances as an expression of severity of cerebral damage.

The present study was designed to validate our ongoing clinical observations, which reveal that distinct clusters of psychiatric symptoms tend to develop following mild or severe brain injury, independently of injury location. These clusters are termed "Extroversion" and "Introversion" syndromes respectively. The symptoms constituting each syndrome manifest themselves along four domains: behavior, personality, affect and cognition. The study sample included 85 brain-injured patients recalled for a follow-up examination 2-3 years after discharge from hospital. Classification into Extroversion and Introversion was done on the basis of a structured psychiatric interview. Severity of brain damage was independently assessed by combinations of five parameters: unconsciousness and PTA duration, cognitive deficiencies, communication and locomotor disorders. The results supported our clinical observations, suggesting that severity of brain damage could also be assessed by the nature of psychiatric symptomatology exhibited following the injury.

Adolescent↗