A Culturally and Linguistically Appropriate Telephone Support Intervention for Diverse Family Caregivers of Persons With Dementia During the COVID-19 Pandemic.

Caregivers of persons with dementia (PWDs) were socially isolated with little support during the COVID-19 pandemic "Stay-At-Home" order in the United States. To enhance social and emotional connection for diverse caregivers, a culturally/linguistically appropriate telephone intervention provided compassionate listening, mindful breathing, and COVID-19 safety education. The study purpose was to understand caregiving challenges and to evaluate the intervention for caregivers during the early pandemic using a qualitative approach. Twenty-three caregivers participated in the intervention provided by bilingual research assistants for 3 months. Call logs were used to describe the caregivers' dialogue. Thematic analysis identified (a) the challenges, including fear of coronavirus disease, providing around-the-clock care, and forced isolation and negative emotions; and (b) caregivers' experience with the intervention, including connecting with the outside, relief from emotional stress, reliable COVID-19 information, and reinformed caregiving skills. Results suggest that the telephone support was of benefit to diverse caregivers of PWDs during the pandemic by promoting social connection and reducing emotional distress.

Relationships within MOMS Orange County care coordinated home visitation perinatal program.

PURPOSE: The study aimed to examine how registered nurses (RNs) and paraprofessional home visitors (PHVs) work together as a team to care for underserved perinatal women in a coordinated home visitation program. DESIGN AND METHODS: Qualitative methods were used to understand the perspectives of three RNs and twenty PHVs who worked at MOMS Orange County, a community-based perinatal health program. Individual one-on-one interviews were administered with the RNs and focus groups with the PHVs. Qualitative content analysis was conducted to synthesize themes. RESULTS: RNs perceived themselves as educators, mentors, and supervisors. PHVs thought of themselves as supporters, coaches, and advocates. Interdependence and proactive communication were favorable characteristics of the relationship in which RNs trained PHVs to provide health education. The positive interactions between RNs and PHVs appeared to enhance the client-healthcare provider connection. CONCLUSIONS: Our study is one of the first to describe relationships and communication patterns among the healthcare team in a coordinated home visitation program in the United States. Future studies should examine how additional members of the team, including clients and healthcare providers, view their experiences with a home visitation program.

Caregiving Experience of Dementia among Korean American Family Caregivers.

Dementia is a major public health problem affecting 5.5 million people in USA. This qualitative study explored the caregiving experience of Korean American (KA) families of persons with dementia (PWD). Adult KA caregivers of PWD (n = 18) were recruited for semi-structured interviews. Thematic analysis yielded four themes: challenges in finding resources, struggling with mental health issues, traveling the path of acceptance, and finding ways to survive. Due to the language barrier, most KA caregivers reported using Korean Internet for information on dementia and caregiving. Some traveled to South Korea seeking medical assistance for dementia (medical tourism). Importantly, some KA caregivers expressed suicidal thoughts and depression. Unexpectedly, familism prevented help seeking and possible relief from their difficulties. There is an urgent need to improve access to dementia care services and education for the KA community. Building a trusting relationship with healthcare providers is even more important for KA caregivers to address their mental health concerns.

Hispanic Mothers' Experiences with School-Based Emotional Health Curriculum and Perspectives of Their Own Mental Health Needs.

An Emotional Health Curriculum (EHC) was developed to promote positive mental health in primarily Hispanic elementary school-aged children. In order to further expand the EHC, the mothers' experiences with the curriculum were examined. Eighteen mothers participated in two focus groups. Mothers reported that they valued this curriculum as a preventive program. Importantly, all mothers wished to extend their involvement to not only assisting their child in completing the curriculum homework but also attending a proposed parenting program. This study provides preliminary evidence that mothers embraced the EHC as an accessible community mental health service for their children and sought greater involvement.

Emotional and Behavioral Health Needs in Elementary School Students in an Underserved Hispanic Community.

High rates of mental health problems in adolescents have been well documented; less is known about elementary school children in disadvantaged communities. We examined emotional and behavioral health needs in 202 third and fourth graders enrolled in a charter school in a largely Hispanic community. The child-reported Revised Child Anxiety and Depression Scale-25 and Teacher's Report Form were used to evaluate mental health needs as perceived by these children and their teachers. The prevalence of teacher-reported depression and child self-reported anxiety was 7.0% and 6.67%, respectively. Living in a single parent household was found to be a specific risk factor in that those children had higher rates of emotional and behavioral problems than children living with both parents. Evidence of higher depression and anxiety identified in this sample compared to national representative data suggests the need for development of culturally sensitive early prevention and intervention in this underserved community.

Effect of high-frequency chest wall oscillation versus chest physiotherapy on lung function after lung transplant.

PURPOSE: The aim of this study is to compare the effects of chest physiotherapy (CPT) and high-frequency chest wall oscillation (HFCWO) on lung function in lung transplant recipients. BACKGROUND: Chest physiotherapy and HFCWO are routinely used after lung transplant to attenuate dyspnea, increase expiratory flow, and improve secretion clearance. METHODS: In a two-group experimental, crossover design with repeated-measures, 45 lung transplant recipients (27 single, 18 bilateral; 64% male; mean age, 57 years) were randomized to receive CPT at 10:00 AM and 2:00 PM followed by HFCWO at 6:00 PM and 10:00 PM (n=22) or vice versa (n=23) on postoperative day 3. Dyspnea (modified Borg score), Spo2/FiO2, and peak expiratory flow (PEF) were measured pre-treatment and post-treatment. Data were analyzed using chi-square tests, t tests, and linear mixed effects models. RESULTS: There was no statistically significant treatment effect for dyspnea or PEF in patients who received HFCWO versus CPT. However, there was a significant treatment effect on the Spo2/FiO2 ratio (p<0.0001). CONCLUSIONS: Preliminary results suggest that lung function (measured by Spo2/FiO2) improves with HFWCO after lung transplantation. Although dyspnea and PEF did not differ significantly between treatment types, HFCWO may be an effective, feasible alternative to CPT.

Longitudinal changes in objective sleep parameters during pregnancy.

BACKGROUND: Sleep disturbances are associated with adverse perinatal outcomes. Thus, it is necessary to understand the continuous patterns of sleep during pregnancy and how moderators such as maternal age and pre-pregnancy body mass index impact sleep. OBJECTIVE: This study aimed to examine the continuous changes in sleep parameters objectively (i.e. sleep stages, total sleep time, and awake time) in pregnant women and to describe the impact of maternal age and/or pre-pregnancy body mass index as moderators of these objective sleep parameters. DESIGN: This was a longitudinal observational design. METHODS: Seventeen women with a singleton pregnancy participated in this study. Mixed model repeated measures were used to describe weekly patterns, while aggregated changes describe these three pregnancy periods (10-19, 20-29, and 30-39 gestational weeks). RESULTS: For the weekly patterns, we found significantly decreased deep (1.26 ± 0.18 min/week, p < 0.001), light (0.72 ± 0.37 min/week, p = 0.05), and total sleep time (1.56 ± 0.47 min/week, p < 0.001) as well as increased awake time (1.32 ± 0.34 min/week, p < 0.001). For the aggregated changes, we found similar patterns to weekly changes. Women (⩾30 years) had an even greater decrease in deep sleep (1.50 ± 0.22 min/week, p < 0.001) than those younger (0.84 ± 0.29 min/week, p = 0.04). Women who were both overweight/obese and ⩾30 years experienced an increase in rapid eye movement sleep (0.84 ± 0.31 min/week, p = 0.008), but those of normal weight (<30 years) did not. CONCLUSION: This study appears to be the first to describe continuous changes in sleep parameters during pregnancy at home. Our study provides preliminary evidence that sleep parameters could be potential non-invasive physiological markers predicting perinatal outcomes.

Brain Changes Linked to Cognitive Symptomatology in Homeless Youth.

Youth impacted by homelessness experience diminished cognition due to a variety of reasons including mental health symptoms, alcohol and substance use, and adverse childhood experiences. However, the status of specific brain regions which could impact important cognitive functions in homeless youth remains unclear. In this pilot comparative and correlational study, a series of demographic, psychological, cognitive assessments, and brain magnetic resonance imaging were performed in 10 male youth experiencing homelessness and 9 age-matched healthy male controls (age range: 18-25 years). Participants experiencing homelessness had significantly decreased regional brain gray matter tissue in comparison to the controls. Moreover, there were strong inverse correlations between the brain regions classically associated with executive decision-making (prefrontal cortices), depression (insular lobes), and conflict resolution (anterior cingulate), and the level of the symptoms detected by their questionnaires.

Grit Levels of Graduate Nursing Students: Why Grit Is Needed in Nursing.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has created a need for nurses who are perseverant and passionate, the definition of grit. This study examined grit levels in Master in Nursing (MSN) and Doctor of Nursing Practice (DNP) students. METHOD: MSN and DNP students were surveyed using the Grit-S scale, which is composed of two parts: Grit-CI (consistency of interest) and Grit-PE (perseverance of effort). RESULTS: Overall, graduate nursing students had high levels of grit as measured by the Grit-S (M = 3.9, SD = 0.5). Perseverance was higher for both MSN and DNP students than passion (M = 4.2, SD = 0.5 vs. M = 3.6, SD = 0.7). There was no difference in Grit-S levels related to program type. CONCLUSION: Graduate nursing students had high levels of grit. With the challenges faced by nursing professionals during the COVID-19 pandemic, nurses with high grit levels may avoid burnout and persevere though challenges. [J Nurs Educ. 2022;61(4):197-200.].

A Micro-Level Analysis of Physiological Responses to COVID-19: Continuous Monitoring of Pregnant Women in California.

Continuous monitoring of perinatal women in a descriptive case study allowed us the opportunity to examine the time during which the COVID-19 infection led to physiological changes in two low-income pregnant women. An important component of this study was the use of a wearable sensor device, the Oura ring, to monitor and record vital physiological parameters during sleep. Two women in their second and third trimesters, respectively, were selected based on a positive COVID-19 diagnosis. Both women were tested using the polymerase chain reaction method to confirm the presence of the virus during which time we were able to collect these physiological data. In both cases, we observed 3-6 days of peak physiological changes in resting heart rate (HR), heart rate variability (HRV), and respiratory rate (RR), as well as sleep surrounding the onset of COVID-19 symptoms. The pregnant woman in her third trimester showed a significant increase in resting HR (p = 0.006) and RR (p = 0.048), and a significant decrease in HRV (p = 0.027) and deep sleep duration (p = 0.029). She reported experiencing moderate COVID-19 symptoms and did not require hospitalization. At 38 weeks of gestation, she had a normal delivery and gave birth to a healthy infant. The participant in her second trimester showed similar physiological changes during the 3-day peak period. Importantly, these changes appeared to return to the pre-peak levels. Common symptoms reported by both cases included loss of smell and nasal congestion, with one losing her sense of taste. Results suggest the potential to use the changes in cardiorespiratory responses and sleep for real-time monitoring of health and well-being during pregnancy.

Exercise and Stress in At-Risk Women during Pregnancy and Postpartum.

PURPOSE: We aimed to understand the relationship between exercise and stress among socioeconomically at-risk women who participated in a home visitation service during pregnancy and postpartum. METHODS: A mixed-methods design was used to support and supplement quantitative data using qualitative data. Convenience sampling was used to collect data from at-risk women via questionnaires and follow-up interviews. The Perceived Stress Scale was used to assess stress. Frequency and duration of exercise were assessed based on the American College of Obstetricians and Gynecologists exercise guidelines. Regression analyses examined the association between stress and exercise controlling for covariates. Content analysis was used to understand women's stress management experiences. RESULTS: N = 114 women completed the questionnaire and a subgroup of 11 received follow-up interviews. Greater frequency of exercise was significantly associated with lower levels of stress. Approximately one-third of women reported experiencing significant stress. Talking to their husband or partner was the most used and exercise was the least used coping strategy. Many women recognized the importance of managing stress and benefits of exercise, but were hindered by barriers such as feeling tired, preventing them from exercising. CLINICAL IMPLICATIONS: A personalized and safe exercise program has the potential to be a low-cost stress management strategy for women during pregnancy and postpartum.

A Technology-Based Pregnancy Health and Wellness Intervention (Two Happy Hearts): Case Study.

BACKGROUND: The physical and emotional well-being of women is critical for healthy pregnancy and birth outcomes. The Two Happy Hearts intervention is a personalized mind-body program coached by community health workers that includes monitoring and reflecting on personal health, as well as practicing stress management strategies such as mindful breathing and movement. OBJECTIVE: The aims of this study are to (1) test the daily use of a wearable device to objectively measure physical and emotional well-being along with subjective assessments during pregnancy, and (2) explore the user's engagement with the Two Happy Hearts intervention prototype, as well as understand their experiences with various intervention components. METHODS: A case study with a mixed design was used. We recruited a 29-year-old woman at 33 weeks of gestation with a singleton pregnancy. She had no medical complications or physical restrictions, and she was enrolled in the Medi-Cal public health insurance plan. The participant engaged in the Two Happy Hearts intervention prototype from her third trimester until delivery. The Oura smart ring was used to continuously monitor objective physical and emotional states, such as resting heart rate, resting heart rate variability, sleep, and physical activity. In addition, the participant self-reported her physical and emotional health using the Two Happy Hearts mobile app-based 24-hour recall surveys (sleep quality and level of physical activity) and ecological momentary assessment (positive and negative emotions), as well as the Perceived Stress Scale, Center for Epidemiologic Studies Depression Scale, and State-Trait Anxiety Inventory. Engagement with the Two Happy Hearts intervention was recorded via both the smart ring and phone app, and user experiences were collected via Research Electronic Data Capture satisfaction surveys. Objective data from the Oura ring and subjective data on physical and emotional health were described. Regression plots and Pearson correlations between the objective and subjective data were presented, and content analysis was performed for the qualitative data. RESULTS: Decreased resting heart rate was significantly correlated with increased heart rate variability (r=-0.92, P<.001). We found significant associations between self-reported responses and Oura ring measures: (1) positive emotions and heart rate variability (r=0.54, P<.001), (2) sleep quality and sleep score (r=0.52, P<.001), and (3) physical activity and step count (r=0.77, P<.001). In addition, deep sleep appeared to increase as light and rapid eye movement sleep decreased. The psychological measures of stress, depression, and anxiety appeared to decrease from baseline to post intervention. Furthermore, the participant had a high completion rate of the components of the Two Happy Hearts intervention prototype and shared several positive experiences, such as an increased self-efficacy and a normal delivery. CONCLUSIONS: The Two Happy Hearts intervention prototype shows promise for potential use by underserved pregnant women.

Hypothalamic--pituitary-- adrenal axis dysregulation in women with irritable bowel syndrome in response to acute physical stress.

Irritable bowel syndrome (IBS) supports the concept of a dysregulated hypothalamic-pituitary-adrenal (HPA) axis. This study investigates the neuroendocrine and psychological responses to the acute physical stress of a lumbar puncture (LP) in women with diarrhea-predominant IBS by assessing central and peripheral HPA activity and affective measures. Blood samples have been collected at baseline and immediately post- and 1 hr following LP from 13 women with IBS and 13 controls. Plasma adrenocorticotropic hormone (ACTH), cortisol, epinephrine, and norepinephrine levels are analyzed. A single measure of cerebrospinal fluid (CSF) concentrations of corticotropin-releasing factor (CRF(CSF)) and norepinephrine(CSF) is noted. Affective assessments are used to rate anxiety and depression with the Hospital Anxiety and Depression Scale (HADS) and acute mood state is rated using the Stress Symptom Rating questionnaire (stress, anxiety, anger, arousal). The women with IBS display blunted ACTH and cortisol responses to the LP along with a profile of affective responsiveness suggestive of chronic psychosocial stress, although no CRF(CSF) differences between groups are observed.

Predictors of Timely Prenatal Care Initiation and Adequate Utilization in a Sample of Late Adolescent Texas Latinas.

INTRODUCTION: Little is known of late adolescent Texas Latinas' prenatal care perceptions or how these perceptions predict timely prenatal care initiation or adequate utilization. Hence, the purpose of this study is to describe and compare these perceptions between participants with timely versus late prenatal care initiation and adequate, intermediate, and inadequate prenatal care utilization; and to determine predictors of timely prenatal care initiation and adequate utilization. METHODS: Fifty-four postpartum Latinas were recruited through social media. Eligibility criteria were 18 to 21 years old, Texas-born, primiparous, uncomplicated pregnancy/delivery, and English literate. Prenatal care perceptions were measured with the Revised Better Babies Survey and Access Barriers to Care Index. RESULTS: Participants had favorable views of prenatal care benefits; however, not living with the baby's father predicted inadequate prenatal care, Wald χ2(1) = 4.93, p = .026. Perceived benefits of timely and adequate prenatal care predicted timely prenatal care initiation, χ2(1) = 7.47, p = .006. Self-reported depression during pregnancy predicted timely entry into prenatal care, χ2(1) = 4.73, p = .03. CONCLUSION: Participants' positive prenatal care perceptions did not predict adequate prenatal care utilization, indicating that barriers serve as powerful obstacles in late adolescent Texas Latinas.

A Transmedia Storytelling Intervention With Interactive Elements to Benefit Latinas' Mental Health: Feasibility, Acceptability, and Efficacy.

BACKGROUND: Latinos report higher rates of depression and anxiety than US whites but are less likely to receive care. Transmedia storytelling interventions accessible on the Internet via smartphones, tablets, and computers hold promise for reducing reluctance to explore or get help for symptoms because they are private, convenient, and can reach large numbers of people, including Latinas with mental health needs. OBJECTIVE: The purpose of this study was to examine the feasibility, acceptability, and preliminary efficacy of a mental health transmedia intervention for Latinas with elevated symptoms of depression, anxiety, or both. METHODS: A total of 28 symptomatic English-speaking Latina women aged 21 to 48 years participated in a 6-week study using a within-group design. All aspects of the study were completed via telephone or Internet. Participants used their personal devices to engage the Web-based transmedia intervention (in English) that included story-based videos, a data-informed psychotherapeutic video, an interactive video sequence, and a blog written from the point of view of one of the characters with links to mental health resources. Perceived confidence to get help and perceived importance for seeking immediate help were both measured using single-item questions. Participants completed surveys at baseline (via telephone) and 1 and 6 weeks after media engagement that measured various factors, including depression (Patient Health Questionnaire; PHQ-9 and PHQ-8) and anxiety (Generalized Anxiety Disorder scale; GAD-7). A telephone interview was conducted within 72 hours of media engagement. Action taken or intentions to get help (single-item question) and talking about the videos with others (single-item question) were measured 1 and 6 weeks after media engagement. Repeated measures analysis of variance was used to assess change in depression (PHQ-8) and anxiety (GAD-7) before transmedia engagement and 1 and 6 weeks after. Spearman correlations evaluated the association of confidence and importance of getting help with action taken, anxiety, and depression. RESULTS: All 28 Latinas (English speakers) who engaged with the transmedia remained in the 6-week study. Within 1 week of transmedia engagement, 39% of women took action to get help, and 82% discussed the media with others. Symptoms of depression (F2,54=9.0, P<.001) and anxiety (F2,54=18.7, P<.001) significantly reduced across time. Higher levels of confidence were significantly associated with actions taken at 1 (P=.005) and 6 weeks (P=.04), and higher levels of importance were significantly associated with actions taken at 1 (P=.009) and 6 weeks (P=.003). Higher levels of confidence were associated with lower levels of depression (P=.04) and anxiety (P=.01) at 6 weeks. CONCLUSIONS: Preliminary findings indicate a culturally tailored mental health transmedia intervention is a feasible approach that holds promise for engaging large numbers of symptomatic English-speaking Latina women to begin the process of seeking help, as well as decreasing symptoms of anxiety and depression.

Feasibility of an emotional health curriculum for elementary school students in an underserved Hispanic community.

PROBLEM: Hispanic children have greater mental health challenges but fewer received mental health services than other ethnic groups. A classroom-based Emotional Health Curriculum (EHC) was developed to address mental health disparities in an underserved Hispanic community. METHODS: A quasi-experimental design with one group pre- and post-intervention was used to test the feasibility of an 8-week EHC for one hundred 3rd and 4th grade children in a dual-immersion Spanish-English elementary school. Limited efficacy was measured by changes in depression and anxiety scores reported by children and teachers. Acceptance was evaluated by a child-reported satisfaction survey and a focus group in which the four teachers shared their experiences. Implementation was measured by participation, retention, and fidelity rates. FINDINGS: The child-reported depression and anxiety and teacher-reported depression were significantly decreased in at-risk children with the effect size ranging from 0.60 to 1.16 (ps < 0.05). The majority of children (89.7%) enjoyed the EHC and teachers observed that children had acquired skills to manage their emotional distress. The participation, retention, and fidelity rates were 98%, 94%, and 99.13%, respectively. CONCLUSIONS: The results provide promising evidence that the EHC has the potential to improve depression and anxiety symptoms in at-risk children.

Heightened cocaine and food self-administration in female rats with neonatal isolation experience.

Previously, we demonstrated that the early life stress of neonatal isolation facilitates acquisition of cocaine and food self-administration in adult female rats. We now test whether it enhances responding for these reinforcers after operant performance is established. Adult female rats were derived from litters that were either subjected to neonatal isolation (1 h/day isolation; postnatal days 2-9) or were nonhandled and assigned to one of two experiments. In Experiment 1, female rats well trained to self-administer cocaine were tested under a fixed-ratio 3 (FR3) schedule with several cocaine doses (0.0625-1.0 mg/kg/infusion) and under a progressive-ratio (PR) schedule (0, 0.5, and 1.0 mg/kg/infusion cocaine). In Experiment 2, female rats well trained to respond for food reinforcers under an FR15 schedule were tested under two PR schedules. Results show that neonatal isolation enhanced responding for cocaine under both schedules of reinforcement and increased responding for food under a PR schedule of reinforcement. These data extend our previous acquisition study in female rats to show that neonatal isolation enhances responding under maintenance conditions. These enduring behavioral changes may relate to the ability of neonatal isolation to increase striatal dopamine responses to psychostimulants, effects we showed previously in infant and juvenile rats. Neuropsychopharmacology (2006) 31, 70-76. doi:10.1038/sj.npp.1300779; published online 1 June 2005.

Neonatal isolation alters estrous cycle effects on ventral striatal extracellular monoamine levels.

We demonstrated that neonatal isolation (ISO) enhances cocaine self-administration in male and female adult rats and alters ventral striatal extracellular levels of serotonin (5-HT) and dopamine (DA) basally or in response to psychostimulants in infant rats. Now, we examine basal 5-HT, DA, and norepinephrine (NE) levels in nucleus accumbens (NAc) using in vivo microdialysis in adult male and female rats with or without ISO experience. NAc shows estrous cycle-dependent effects as do behavioral responses to cocaine. Because our prior work showed ISO eliminated estrous-cycle effects on behavior, we now test separate groups of females in proestrus, estrus, or diestrus stages. Litters were assigned to the ISO (1-h isolation; postnatal days 2-9) or non-handled (NH) condition. During adulthood (postnatal day 70-90), microdialysis probes were implanted and aimed at NAc core. Ten samples were collected over 150-min and measures of 5-HT, DA, and NE were analyzed via HPLC. ISO did not affect 5-HT levels in males. However, ISO modified estrous stage effects on 5-HT. The pattern of 5-HT levels in NH females (higher in diestrus and proestrus vs. estrus) was reversed in ISO females. DA levels were unaffected by ISO, similar to our findings at other ages, and did not differ by gender or estrous stage. None of these factors affected NE levels. Because 5-HT modulates DA and levels of both transmitters are increased by cocaine, this neurochemical effect of ISO may contribute to the ability of ISO to alter the behavioral responses to cocaine as we showed previously.

Neonatal isolation alters the estrous cycle interactions on the acute behavioral effects of cocaine.

We demonstrated that neonatal isolation (ISO) increases acquisition of cocaine self-administration and alters psychostimulant-induced ventral striatal dopamine and serotonin levels in female rats. Both dopamine and serotonin modulate the behavioral effects of cocaine and these effects can vary across estrous stages. We now test whether ISO modifies the manner in which estrous stage affects the acute behavioral responses to cocaine. Litters were assigned to ISO (1 h/day isolation; post-natal days 2-9) or non-handled (NH) conditions. In Experiment 1, the ability of cocaine (0.3-30 mg/kg; IP) to disrupt schedule-controlled responding for food was assessed in proestrus, estrus, and diestrus stages. Diestrus and proestrus NH females showed increased response rates at low cocaine doses and decreased rates at higher doses relative to baseline. In contrast, estrus NH females showed decreased responding across all doses. ISO eliminated this estrous stage distinction; only decreased responding to high cocaine doses were seen. Yet, estrous cyclicity during food restriction (Experiment 2) did not differ by group. To confirm this ISO effect, proestrus or estrus rats were administered cocaine (0, 5, 10 mg/kg; IP) and activity monitored in Experiment 3. Locomotor activity differed by estrous stage in NH but not ISO rats. Cocaine plasma levels (Experiment 4) at the time of peak behavioral activity did not differ by group or estrous stage. Results extend prior studies to show estrous stage alters the behavioral effects of cocaine. Neonatal isolation eliminates these effects perhaps reflecting alterations in accumbens monoamine levels or the effects of estrogen on this system.

Neonatal isolation enhances maintenance but not reinstatement of cocaine self-administration in adult male rats.

RATIONALE: Previously, we demonstrated that neonatal isolation increases acquisition of cocaine self-administration in adult male rats. OBJECTIVE: Now we examine whether neonatal isolation enhances maintenance and cocaine-induced reinstatement of extinguished self-administration behavior. To test the specificity of the effect, a separate study examined maintenance of food responding. METHODS: Litters were subjected to neonatal isolation (individual isolation; 1 h/day; postnatal days 2-9) or were non-handled. In experiment 1, adult male rats trained to self-administer cocaine (0.5 mg/kg per infusion; fixed-ratio 3 or FR3) were tested under fixed and progressive ratio (PR) schedules with different cocaine doses (0.125-1.0 mg/kg per infusion). After cocaine self-administration was extinguished, cocaine (0.5 or 2 mg/kg)-induced reinstatement of responding was assessed. In experiment 2, responding for food under an FR15 and two PR schedules were assessed in separate groups of neonatally isolated and non-handled male rats. RESULTS: Neonatally isolated rats responded for low cocaine doses at higher rates and infused more cocaine relative to non-handled rats under both FR and PR schedules. However, there are no group differences in cocaine-induced reinstatement or in responding for food under the PR schedules. However, neonatally isolated rats lever pressed for food at lower rates under the FR schedule. CONCLUSIONS: Together with our previous studies, the results of the present study suggest that the early life stress of neonatal isolation enhances cocaine-taking (acquisition and maintenance) at lower doses but does not alter drug-induced cocaine-seeking (reinstatement) behavior.