Postpartum Females Research Articles

Reproductive Features and Faecal Progesterone Metabolite Profile in Female Ferrets

Elevated post-partum progesterone metabolite (P(4) -met) levels have been recently postulated to occur in lactating lynxes. The aims of this study were to monitor reproductive features in female ferrets, changes in the faecal P(4) -met concentrations throughout the breeding season and ovarian activity in post-partum lactating and non-lactating (NL) female ferrets. Our results indicate that coinciding with the results described in the lynx, elevated faecal P4-met concentrations occur in lactating ferrets, furthermore, that the duration of elevated secretion of P(4) seems to be dependent on the duration of lactation (P4-met at delivery, n=47: <500 ng/g; 5-7 days after delivery, during lactation, n=47: ≥ 500-800 ng/g; in females weaned at delivery, n=4: baseline levels). Three days after ovariohysterectomy of lactating females, P(4) -met concentrations decreased to baseline levels. In lactating females, the ovarian stroma is more active than that in NL ones implicating that the ovary is at least in part responsible for the elevated P4-met concentrations. Ovaries of lactating females contained many luteinized cells either as luteinized granulose cells in the wall of late pre-antral/early antral follicles or as corpus luteum (CL)-like structures. Early resumption of the entire ovarian activity (developed follicles and oestrus) occurs in NL post-partum females, while final follicular development is blocked (follicles stalls at antral stage) in the lactating ones (however, occasionally lactational oestrus may occur). We suppose that the elevated faecal P4-met during lactation together with suckling and other hormonal effects may contribute to prevention of early returning to oestrus in nursing female ferrets.

Tobacco induced severe oxidation of plasma cysteine redox in post-partum females

Introduction: While increased oxidant stress is implicated in a variety of maternal and neonatal complications, the effects of tobacco-induced alterations in systemic redox status remains clinically unrecognized. We hypothesized that maternal smoking would increase systemic oxidant stress during pregnancy in the otherwise healthy female. Methods: We evaluated plasma samples from 212 post partum women as part of a larger parent investigation of mother-infant pairs. An extensive maternal interview noted tobacco, alcohol, cocaine or marijuana use throughout the pregnancy. The redox pairs of glutathione/oxidized GSSG and cysteine/oxidized cystine were measured in the plasma by high performance liquid chromatography. Results: Over 64.5% of the sample reported tobacco use during pregnancy. Tobacco-exposed newborns demonstrated lower birth weight, decreased head circumference and birth length. Maternal tobacco use decreased maternal cysteine by 10% and cysteine/cystine redox potential was dramatically oxidized by >20 mV, independent of alcohol, marijuana or cocaine use. Conclusion: Significant oxidation of maternal cysteine/cystine redox pair occurred before clinically apparent decreases in newborn birth weight. We concluded that tobacco use during pregnancy was associated with significant oxidation of the cys- teine/cystine redox pair in the otherwise healthy post partum women. The implications of unrecognized derangements of systemic redox on the health of the mother and infant require evaluation.

N-3 (omega-3) Fatty acids in postpartum depression: implications for prevention and treatment.

A growing body of clinical and epidemiological evidence suggests that low dietary intake and/or tissue levels of n-3 (omega-3) polyunsaturated fatty acids (PUFAs) are associated with postpartum depression. Low tissue levels of n-3 PUFAs, particularly docosahexaenoic acid (DHA), are reported in patients with either postpartum or nonpuerperal depression. Moreover, the physiological demands of pregnancy and lactation put childbearing women at particular risk of experiencing a loss of DHA from tissues including the brain, especially in individuals with inadequate dietary n-3 PUFA intake or suboptimal metabolic capabilities. Animal studies indicate that decreased brain DHA in postpartum females leads to several depression-associated neurobiological changes including decreased hippocampal brain-derived neurotrophic factor and augmented hypothalamic-pituitary-adrenal responses to stress. Taken together, these findings support a role for decreased brain n-3 PUFAs in the multifactorial etiology of depression, particularly postpartum depression. These findings, and their implications for research and clinical practice, are discussed.

Effect of the adenosine A2A receptor antagonist MSX-3 on motivational disruptions of maternal behavior induced by dopamine antagonism in the early postpartum rat

Mesolimbic dopamine (DA), particularly in the nucleus accumbens, importantly regulates activational aspects of maternal responsiveness. DA antagonism and accumbens DA depletions interfere with early postpartum maternal motivation by selectively affecting most forms of active maternal behaviors, while leaving nursing behavior relatively intact. Considerable evidence indicates that there is a functional interaction between DA D2 and adenosine A(2A) receptors in striatal areas, including the nucleus accumbens. This study was conducted to determine if adenosine A(2A) receptor antagonism could reverse the effects of DA receptor antagonism on early postpartum maternal behavior. The adenosine A(2A) receptor antagonist MSX-3 (0.25-2.0 mg/kg, IP) was investigated for its ability to reverse the effects of the DA D2 receptor antagonist haloperidol (0.1 mg/kg, IP) on the maternal behavior of early postpartum female rats. Haloperidol severely impaired the expression of active maternal components, including retrieval and grouping the pups at the nest site, pup licking, and nest building. Co-administration of MSX-3 (0.25-2.0 mg/kg, IP) with haloperidol produced a dose-related attenuation of the haloperidol-induced behavioral deficits in early postpartum females. Doses of MSX-3 that effectively reversed the effects of haloperidol (0.5, 1.0 mg/kg), when administered in the absence of haloperidol, did not affect maternal responding or locomotor activity. Adenosine and DA systems interact to regulate early postpartum maternal responsiveness. This research may potentially contribute to the development of strategies for treatments of psychiatric disorders during the postpartum period, with particular emphasis in maintaining or restoring the mother-infant relationship.

Forced swim test behavior in postpartum rats

This study was undertaken to determine whether depression-like behavior can be observed in gonadally intact females that have experienced normal pregnancy. When tested on the forced swim test (FST) on postpartum days 1–7, previously pregnant rats spent slightly more time immobile, significantly less time swimming and diving, and defecated more than virgin controls. Subchronic treatment with nomifensine (DA reuptake inhibitor, 2.5 mg/kg) but not sertraline (serotonin reuptake inhibitor, 10 mg/kg) or desipramine (norepinephrine reuptake inhibitor, 10 mg/kg) significantly decreased immobility on postpartum day 2. In rats pre-exposed to the FST in mid-pregnancy, neither subchronic nor chronic treatment with desipramine or sertraline decreased immobility on postpartum day 2; in contrast, chronic desipramine significantly decreased immobility in virgin controls. These results indicate that postpartum female rats, compared to virgin controls, show a reduction in some “active coping behaviors” but no significant increase in immobility when tested during the early postpartum period, unlike ovariectomized females that have undergone hormone-simulated pregnancy (HSP). Additionally, immobility that is increased by FST pre-exposure is not readily prevented by treatment with standard antidepressant medications in postpartum females. Depression-like behaviors previously observed in females that have undergone HSP may result from the more dramatic changes in estradiol, prolactin or corticosterone that occur during the early “postpartum” period, compared to the more subtle changes in these hormones that occur in actual postpartum females.

Pregnancy and fetal outcomes of symptoms of sleep-disordered breathing

The physiological changes of pregnancy may predispose females to develop sleep-disordered breathing (SDB) or protect against it. Studies evaluating outcomes of SDB symptoms in pregnancy are scarce. The goal of this study was to evaluate the prevalence of SDB symptoms in pregnancy and their relationship with pregnancy and neonatal outcomes. A cross-sectional survey of randomly selected immediate postpartum females was performed using the multivariable apnoea prediction index. Record review, including demographics and medical history, was performed. Main outcome measures included pregnancy and neonatal outcomes. 1,000 subjects were recruited. Mean±sd age was 29.1±6.1 yrs. Factors used in the regression analysis included age, body mass index, diabetes, chronic hypertension, multifetal gestations, smoking and renal disease. Snoring was present in 35.1% of subjects. Symptoms of SDB were associated with a higher likelihood of pregnancy-induced hypertension and pre-eclampsia (adjusted OR 2.3, 95% CI 1.4-4.0), gestational diabetes (adjusted OR 2.1, 95% CI 1.3-3.4) and unplanned Caesarean deliveries (adjusted OR 2.1, 95% CI 1.4-3.2) after multivariable regression analysis. Gasping may have been associated with a higher likelihood of preterm delivery, after adjusting for age and multifetal pregnancies (adjusted OR 1.8, 95% CI 1.1-3.2) but this association appeared to be mediated by pre-eclampsia. Symptoms of SDB are common in pregnancy and associated with a higher likelihood of gestational hypertensive disorders, gestational diabetes and unplanned Caesarean deliveries.

Phenotypic plasticity in the greater mouse-eared bat in extremely different roost conditions

Bats use various roost types with a wide spectrum of ecological features. The greater mouse-eared bat Myotis myotis (Borkhausen, 1797), creates nurseries in attics and caves in Central Europe. The stable low temperature and high humidity cave microclimate contrasts that of attics, which may alter species adaptations and life strategies. We analysed population characteristics (composition, body condition, parasite load, and immune response) and genetic relatedness of two proximal M. myotis populations. Age, sexual and parasite species composition were similar between the cave and attic sites. However, a significantly higher parasite load and body condition was detected in the post-partum females and juveniles of the cave colony (n = 263 bats from the cave, 231 from the attic), with the cave colony females having a significantly stronger immune response (n = 2 caves and 2 attics, 20 females per site). There was no evidence for genetic divergence between cave and attic populations (n = 3 caves and 3 attics, 24 females per site), indicating that different population characteristics are not genetically based and that M. myotis is an example of a species with rather unique phenotypic plasticity.

The Effective Use of the Pedometer to Increase Walking in Postpartum African American Women

African American women have been reported to have the lowest levels of physical activity as compared to any other population. Additionally, the increased contribution of childbearing to weight gain and consequential obesity found among black women and the physically inactive lifestyle developed among these women by the 6th week postpartum period is of great concern. The benefits of regular physical activity have been well established for the general population; however, physical activity recommendations are seldom included for early postpartum care. PURPOSE: To determine if the use of the pedometer would increase walking (ambulatory movement) in African American women that are between 6 weeks and 6 months postpartum. METHOD: A sample group of 32 apparently healthy postpartum African American females (aged 18-40) that were between 6-8 weeks postpartum and met the inclusion criteria participated in this study. All participants received a Yamax SW-200 pedometer and an activity log with instructions to intentionally increase their average number of steps by at least 500 steps each week beginning from baseline for 12 weeks. RESULTS: A paired t-test analysis revealed a significant increase in daily walking activity (t (30) = -8.204, p <.001) at the end of the 12 week study. An estimate of the magnitude of the effect showed a 64% increase in the average number of steps taken per day by African American women that were between 6 weeks to 6 months postpartum. At the beginning of the study, the women reportedly averaged∼ 5347 steps/day and increased ∼3402 steps/day to an average of ∼8749 daily steps by the end of the study. The proposed indices for public health are: <5000 steps/day for sedentary, 5000-7499 steps/day for low active, 7500-9999 for somewhat active, > /= 10,000 steps/day for active and > 12, 500 steps/day for highly active adults. Based on the proposed (steps/day) indices for public health, the women in this study advanced from the "low active" classification to "somewhat active" by the end of the study. CONCLUSION: The use of the pedometer was effective in increasing walking and promoting increased physical activity, as measured by the average number of daily steps, in African American women that are between 6 weeks and 6 months postpartum.

GABA A receptor antagonism in the ventrocaudal periaqueductal gray increases anxiety in the anxiety-resistant postpartum rat

Postpartum mammals show suppressed anxiety, which is necessary for their ability to appropriately care for offspring. It is parsimonious to suggest that the neurobiological basis of this reduced anxiety is similar to that of non-parturient animals, involving GABA A receptor activity in sites including the midbrain periaqueductal gray (PAG). In Experiment 1, postpartum and diestrous virgin female rats received an intraperitoneal injection of the GABA A receptor antagonist (+)-bicuculline (0, 2 and 4 mg/kg) and anxiety-related behavior was assessed with an elevated plus maze. The 4 mg/kg dose of (+)-bicuculline significantly increased anxiety-related behavior, particularly in the postpartum females. Experiment 2 revealed that bicuculline's action was within the central nervous system, because anxiety in neither dams nor virgins was significantly affected by intraperitoneal injection of bicuculline methiodide (0, 2 and 6 mg/kg), which does not readily cross the blood–brain-barrier. In Experiment 3, bicuculline methiodide (2.5 ng/side) was directly infused into the ventrocaudal PAG (cPAGv) and significantly increased dams' anxiety compared to saline-infused controls. These studies expand our knowledge of how GABA A receptor modulators affect anxiety behaviors in postpartum rats to the widely-used elevated plus maze, and indicate that the postpartum suppression of anxiety is in part a consequence of elevated GABAergic neurotransmission in the cPAGv.

The medial preoptic area is necessary for motivated choice of pup- over cocaine-associated environments by early postpartum rats

Converging evidence suggests that the motivation to seek cocaine during the postpartum period is significantly impacted by the competing incentives of offspring, a stimulus unique to this life stage. In the present study, the functional role of the medial preoptic area (mPOA), a critical site involved in maternal responsiveness, on processing incentive value of pup-associated cues and influencing response allocation for pup- over cocaine-associated environments was investigated using a concurrent pup/cocaine choice conditioned place preference (CPP) paradigm. Early postpartum females with bilateral guide cannulae aimed into the mPOA or into anatomical control sites were conditioned, from postpartum days (PPD) 4 to 7, to associate different uniquely featured environments with pups or cocaine. CPP was tested on PPD8 following intra-mPOA infusions of either 2% bupivacaine or saline vehicle. In two additional experiments, the effects of intra-mPOA infusions of bupivacaine on expression of conditioned responding induced by environments associated with either pups or cocaine were examined separately. Transient inactivation of the mPOA selectively blocked the conditioned preferences for pup-associated environments, significantly contrasting the robust pup-CPP found in non-surgical and intra-mPOA vehicle-treated females. In contrast, mPOA inactivation failed to alter cocaine-CPP in postpartum females. When given a choice between environments associated with pups or cocaine, transient functional inactivation of the mPOA altered choice behavior, biasing the preference of females toward cocaine-associated environments, such that almost all preferred cocaine- and none the pup-associated option. The anatomical specificity was revealed when inactivation of adjacent regions to the mPOA did not affect CPP responses for pups. The findings support a critical role for the mPOA in mediating pup-seeking behavior, and further suggest that the competing properties of pups over alternative incentives, including drugs of abuse, rely on mPOA integrity to provide relevant pup-related information to the circuitry underlying the choice behavior between pups and alternative stimuli.

Bajo peso al nacer: exploración de algunos factores de riesgo en el Hospital Universitario San José en Popayán (Colombia)

Introducción: el bajo peso al nacer (BPN) es un importante problema de salud pública en los países en desarrollo y es un indicador de la salud materno-infantil. El peso al nacer por debajo de 2.500 g contribuye a problemas de salud materno-infantiles de corto y largo plazo.Objetivo: establecer los factores asociados con el bajo peso al nacer en el Hospital Universitario San José, Popayán (Colombia), en el período comprendido entre los años 2005 y 2006.Métodos y materiales: estudio de casos y controles. Los casos (n=344) fueron los recién nacidos con peso menor a 2.500 g que nacieron en este hospital. Los controles (n=483) fueron recién nacidos con peso mayor a 2.500 g que nacieron el mismo día. Se realizó una entrevista en mujeres después del parto para recoger información acerca de los factores de riesgo; y se estimó elOdds Ratio (OR, por sus siglas en inglés) y sus respectivos intervalos de confianza (IC95%) utilizando un modelo de regresión logística.Resultados: como factores de protección se consideraron: antecedentes de estrato socioeconómico medio/superior (OR=0,33; IC95% 0,12-0,91), sexo femenino del recién nacido (OR=0,73; IC95% 0,55-0,98), tener más de 5 controles prenatales (OR=0,54; IC 95% 0,39-0,75) y no tener antecedentes previos de BPN (OR=0,30; IC95% 0,15-0,58). Entre los factores de riesgo se encontraron: antecedentes de infecciones del tracto urinario (OR=1,78; IC95% 1,30-2,45) y cesárea anterior (OR=1,88; IC95% 1,13-3,16).Conclusión: el bajo peso al nacer está asociado con el estrato socioeconómico, por lo que intervenir en la falta de equidad social es un factor de importancia para la reducción del BPN en el área de influencia de este centro de atención terciario.

The condition conundrum: application of multiple condition indices to the dusky shark Carcharhinus obscurus

Measuring fish condition has become a standard practice in the management of fishes, both at the individual and population level. The comparative application of several condition indices to sharks, however, has not yet received a rigorous evaluation. Data for a total of 2120 dusky sharks Carcharhinus obscurus (Lesueur, 1818), ranging in size from newborns (≤79 cm precaudal length (PCL)) to mature adults (≥210 cm PCL), were used to calculate seasonal trends in condition and to facilitate index comparisons. Four commonly used condition measures were selected, including a somatic measure, hepatosomatic index (HSI), and 3 morphometric measures, condition factor (CF), relative condition (Kn) and residual condition (RrPCL). The effect of month was significant for most condition analyses by size class, sex and reproductive state. HSI was found to be the most sensitive index and rapid indicator of condition, but its appropriate use requires the disaggregation of data by clearly defined life stages and reproductive states. The relatively large liver size of neonates and the relatively small liver size of pregnant and postpartum females may otherwise bias interpretations of seasonal variations in condition. HSI was also affected by increasing size of the animal, which con- founds inter-size-class comparisons and may require the further division of life-stage data into addi- tional size classes. The results of the 3 morphometric measures were comparable but were not corre- lated with HSI. CF, Kn and RrPCL lagged behind HSI, were unable to differentiate between neonate and juvenile animals and were insensitive to short-term variations. The effect of increasing size did not affect calculated CF and RrPCL, but Kn demonstrated a negative correlation. The fact that large predators may consume large volumes of food in a single feeding event was identified as a possible complicating factor in interpreting condition indices.

Hormones that increase maternal responsiveness affect accumbal dopaminergic responses to pup- and food-stimuli in the female rat

The present study investigated hormonal mediation of maternal behavior and accumbal dopamine (DA) responses to pup-stimuli, as measured in microdialysis samples collected from the nucleus accumbens shell of female rats in non-homecage environment. In Experiment 1, samples were collected before and after continuous homecage pup experience from either intact postpartum or cycling females. In Experiment 2, samples were collected before and after responding maternally in homecage from ovariectomized females given either parturient-like hormone or sham treatments. After baseline sample collection in the dialysis chamber, pup and food stimuli were individually presented to females. Upon sampling completion, all animals were placed back into their homecage with donor pups for several days, and then the sample collection procedure was repeated. Prior to stimulus presentation, postpartum and hormone-treated females had decreased basal DA release compared to their controls. In response to pup stimuli, only postpartum and hormone-treated females had increased DA release compared to basal release (both sampling days). In response to food stimuli, all females had increased DA responses from basal; although there were group differences on the initial day of sampling. Findings suggest that hormones associated with inducing maternal behavior in the postpartum rat play a significant role in modifying accumbal dopaminergic responses on first exposure to pup stimuli in the rat. However, the postpartum experience provides further modifications to this brain region to promote DA responses to pup stimuli.

Steroid hormones and maternal experience interact to induce glial plasticity in the cingulate cortex

Neocortical plasticity is not usually associated with changes in reproductive function. However, we have shown a six to 10-fold increase in the number of astrocytes labeled with glial fibrillary acidic protein (GFAP) and astrocytic basic fibroblast growth factor or FGF-2 (bFGF) in the cingulate cortex area 2 (Cg2) in postpartum rats, indicative of changes in connectivity in this area. In the present studies, we investigated the necessary and sufficient stimuli for these changes to occur. We show that 3 h of maternal experience combined with a hormonal treatment that mimics late pregnancy induces the astrocytic changes in Cg2 in virgin rats. The extent of these changes was similar to those of postpartum females. Sensitized virgin females did not show any astrocytic changes after 3 h of maternal behavior, suggesting that a similar amount of maternal experience alone is not sufficient to increase astrocytic bFGF- and GFAP-immunoreactivity in Cg2. Consistent with these data, eliminating early maternal experience by removing pups immediately postpartum abolishes the increased bFGF and GFAP protein expression in the cingulate cortex. These results suggest that maternal experience and hormonal state interact to produce astrocytic remodeling in the Cg2. The current results are consistent with a role for the cingulate cortex in maternal responsivity as suggested by early lesion studies in rats and more recent imaging studies in humans.

Transient inactivation of the ventral tegmental area selectively disrupts the expression of conditioned place preference for pup- but not cocaine-paired contexts.

The ventral tegmental area (VTA) plays a critical role in motivated behavior. However, it remains unclear whether intact VTA function is necessary for motivated behavior to seek contexts repeatedly paired with natural stimuli and/or pharmacological stimuli. In the present study, conditioned place preference (CPP) was induced with highly salient natural or drug stimuli attributed with strong incentive-motivational value in each of 2 female models: Postpartum females were conditioned to associate one unique context in the CPP apparatus with young offspring (pups) and a second context with a neutral stimulus, and virgin females were conditioned to associate unique contexts with cocaine (5 mg/kg ip) and saline injections. Immediately before CPP testing, each female received a microinfusion of bupivacaine bilaterally into the VTA to transiently inactivate the region; subjects were also tested after saline microinfusion into the VTA. Postpartum females' preference for the pup-paired context was abolished by VTA inactivation but was restored to high control levels after saline microinfusion. In separate tests, VTA inactivation also reduced motivated pup licking and pup retrieval in postpartum females, suggesting that intact VTA function is required for the expression of both pup CPP and motivated pup-directed behaviors. Cocaine CPP remained unaffected by VTA inactivation. Locomotion was not affected by VTA microinfusions but was severely impaired by bupivacaine microinfusions into the substantia nigra. We concluded that the VTA is differentially involved in the expression of conditioned preference for contexts paired with pups, a salient natural stimulus, and contexts paired with cocaine.

Desmoid tumors of the right rectus abdominus muscle in postpartum women

Desmoid tumors are benign neoplasms that most often arise from muscle aponeurosis and have been associated with both trauma and pregnancy. The etiology of desmoids has not been determined. We present here four almost identical cases with desmoids occurring in the same location, the right rectus abdominus muscle in young post partum females. All were over the age of 30 at the time of diagnosis. Three of them had previously used oral contraceptive agents for an average of 3 years. None had a history of trauma to the area of involvement. Three had early surgical resection and one was treated with tamoxifen and imatinib without response and then had surgical resection. All four patients are disease free at a median follow-up of 2.5 years. The possible etiology of desmoids tumors in this location in postpartum females is discussed.

Reproductive biology of the fanray, Platyrhina sinensis (Batoidea: Platyrhinidae) in Ariake Bay, Japan

The reproductive biology of the fanray, Platyrhina sinensis, was examined in Ariake Bay, Japan, from May 2002 until December 2006. Females reached sexual maturity at a larger size than males [total length (TL) at 50% sexual maturity: male, 393 mm; female, 421 mm]. The present data support a distinct annual reproductive cycle for P. sinensis. The gonadosomatic index (GSI) for mature males showed a clear seasonal trend, declining from August to November. Histological observations showed that mature sperm in the testes occurred from August to November when monthly GSI declined. Concomitantly, pre-ovulatory ova were observed in females collected from August to November. These data indicate that mating, ovulation and fertilization occurred from August to November. Near-term embryos, neonates and recent post-partum females also occurred from August to November. Additionally, all post-partum females possessed large pre-ovulatory ova. Parturition occurred from August to November followed immediately by mating, ovulation and fertilization. Mature females become pregnant every year, and the gestation period is almost 1 year. Fertilized uterine eggs without macroscopic embryonic development were present throughout the annual reproductive cycle, indicating that P. sinensis utilizes embryonic diapause as its reproductive strategy. Both reproductive tracts of females were functional, and fecundity ranged from 1 to 12 with a mean of 6.0, increasing with TL.

CARACTERIZAÇÃO DE UMA PESCARIA DE PEQUENA ESCALA EM UMA ÁREA DE IMPORTÂNCIA ECOLÓGICA PARA ELASMOBRÂNQUIOS, NO RECREIO DOS BANDEIRANTES, RIO DE JANEIRO

A pesca de pequena escala sustenta milhões de pessoas em todo o mundo e opera principalmente na zonacosteira. Esta região é utilizada por muitas espécies de Elasmobrânquios como área de alimentação, reprodução, parto e/ou crescimento. A APREBAN é um grupo de pescadores urbanos de pequena escala que atua na costa do Rio de Janeiro (RJ), principalmente em torno da isóbata de 30 m, empregando redes-de-espera de dimensões e malhas variáveis. Durante dois anos de acompanhamento dos desembarques, registrou-se 1.617 Elasmobrânquios de 27 espécies, incluindo nove ameaçadas de extinção. Diversos estágios de maturação foram observados incluindo neonatos e fêmeas grávidas ou pós-parto de oito espécies, além de Squatina spp. Esta região mostrou-se uma área de importância ecológica para Elasmobrânquios, com especial destaque para Rhizoprionodon spp. Sphyrna spp., Squatina spp., Rhinobatos horkeliie Carcharhinus spp. Recomenda-se um monitoramento mais abrangente da costa do Estado do Rio de Janeiro a fim de melhor caracterizar o usodos habitats costeiros pelos Elasmobrânquios e as formas de interação com a pesca de pequena escala.

Exposure to pups influences the strength of maternal motivation in virgin female rats

Following repeated exposure to foster pups, virgin female rats acquire and eventually express a full spectrum of maternal caretaking behaviors directed toward pups. Though these behaviors are vigorous, these females are reportedly less motivated to seek out and interact with pups (i.e. maternally motivated) than parturient females during early postpartum. The present study systematically assesses how the length of pup-exposure and nature of interactions between the female-pup dyad affect maternal motivation in the virgin female rat. Virgin females were exposed to young pups consistently (24 h/day) across a prolonged period (21 days), briefly (1 h/day) across a relatively brief period (7 days), or distally (pups inaccessible in mesh bag). During final pup-exposure days, females were conditioned and tested for their preference for a pup-associated chamber (e.g. maternal motivation) using conditioned place preference. Early postpartum females provided a comparison group. Fully maternal behavior only emerged in females given prolonged pup-exposure; this behavior improved significantly over time and was maximally expressed for a duration equivalent to early postpartum. Females given brief pup-exposure expressed only emergent maternal behaviors initiated by pups; distal pup-exposure evoked pup-avoidance. Virgin females given prolonged or brief pup-exposure expressed substantial pup-associated chamber preference, with more females preferring the pup-associated chamber following longer pup-exposures in a subtle stepwise relationship. Maternal motivation was strikingly similar in prolonged pup-exposure virgin and early postpartum females. Females given distal pup-exposure completely lacked maternal motivation. Maternal behavior did not predict chamber preference. Results suggest that pup-exposure, regardless of length, is sufficient to support strong maternal motivation, whereas parity is not required.

Incentive salience of cocaine across the postpartum period of the female rat

RATIONALE-OBJECTIVES: Our prior conditioned place preference (CPP) work demonstrates that late (day16) postpartum female rats consistently prefer cocaine- over pup-associated chambers, whereas far fewer early postpartum (day8) females prefer the cocaine-associated chamber. The present study examines early and late postpartum females' preference for a cocaine-associated chamber when contrasted with a chamber associated with saline (rather than pups). Postpartum females were tested for conditioned preference for chambers associated with cocaine (10 mg/kg subcutaneous (SC) or 0.5, 5, 10, or 20 mg/kg intraperitoneal (IP) injections) versus saline; preferences of virgin female and male rats for select cocaine stimuli (10mg/kg SC or IP) were also tested. Locomotion was recorded during CPP conditioning and testing. Early and late postpartum females expressed strikingly similar preference for the cocaine-associated chamber across all administration routes and doses. IP cocaine produced an orderly, inverted U-shaped dose-preference curve, with preference peaking at the 5 mg/kg dose (83% of females). While many postpartum females preferred 10mg/kg cocaine administered either SC or IP, both virgin females and males expressed strong aversion to SC cocaine and, while virgin females strongly preferred IP cocaine, males remained relatively indifferent. Across 10mg/kg IP cocaine-conditioning sessions, locomotor sensitization occurred exclusively in cocaine- but not saline-preferring postpartum females. Locomotor rate was lower in preferred versus nonpreferred chambers at CPP test. Early and late postpartum females may be equally and uniquely susceptible to sampling and/or abuse of modestly salient doses of cocaine (10mg/kg SC; 5mg/kg IP) compared to virgin females and/or males.