Prenatal Hypoxia Ischemia Increases Male Rat Sexual Behavior.

Research consistently indicates an association between prenatal hypoxia-ischemia (HI) and mortality and chronic neurological diseases in newborns. HI can cause permanent effects, including mental retardation, motor impairment, learning disabilities, epilepsy, and cerebral palsy. Moreover, little is known about the relationship between HI and sexual behavior. The aims of this study are to examine whether HI is associated with changes in sexual behavior. HI was induced by clamping the uterine arteries of pregnant rats. The arteries were clamped for 45 minutes on the 18th day of gestation (HI group). Shams received laparotomy and anesthesia only. Pups were born at term. At 90 days of age, sexual behavior was evaluated. Statistical analysis was performed using two-way analysis of variance and post hoc Bonferonni correction. The main outcome measures of sexual response were standard sexual behavior, homosexual behavior, and sexual attempt on nonreceptive females. The stimulatory effect of HI on male rat sexual behavior has been shown in various experimental models; these animals showed reduced mount, intromission and ejaculation latencies; increased copulatory efficiency; and homosexual mounting. Additionally, there was an increase in fighting in trying to mount an unreceptive female. Our results indicate that HI had a long-term effect on sexual behavior despite exhibiting motor skill impairment. Accordingly, injuries during the fetal period may cause behavioral problems in adulthood.

Ferraz MM ，Sab IM ，Silva MA ，Santos DA ，Ferraz MR ... -  《-》

Double perinatal stress reduces the sexual response of adult female Wistar rats.

Early-life stress affects physiological development and produces changes in various aspects of emotional behavior. We sought to examine the effects of double perinatal stress (DPS)-a combination of prenatal systemic hypoxic-ischemic (HI) insults and repeated early maternal separation-on the estrus cycle and sexual behavior of adult rats. HI was induced by clamping the uterine arteries of pregnant rats for 45 minutes on the 18th day of gestation (HI group). Sham control animals received laparotomy and anesthesia only. Pups were born at term. Maternal separation was performed from postnatal day 1 (P1) (P0 = day of birth) to P15. At P90, the sexual response of females in estrus was evaluated. Statistical analysis was performed using 2-way analysis of variance followed by Tukey's test. We considered the estrous cycle and sexual behavior of female rats submitted to DPS, as well as the influence of female behavior on the sexual response of male rats. Rats submitted to DPS showed a reduction in the lordosis quotient and in the lordosis rate, suggesting a reduction in female sexual receptivity. DPS female rats showed a reduction in the number of hops and darts and in the genital exploration time rate, suggesting a reduction in sexual proceptivity. In addition, males that interacted with DPS females showed a reduction in the number of ejaculations and in copulatory efficiency. Developing a deeper understanding of perinatal factors that affect adult female sexual response will allow for more effective interventions to prevent and treat such changes. On the other hand, the analysis of the sexual response allows assessing the quality of life and the general state of health. The development of animal models to investigate the environmental factors that interfere in the female sexual response may allow researchers to propose and test new therapeutic strategies. On the other hand, care must be exercised when interpreting animal data and extrapolating these results to estimate the possible effects of perinatal stressors on the human sexual response. Our results revealed that females subjected to DPS showed long-term effects on sexual behavior. In conclusion, managing stressors in prenatal life and early postnatal life can prevent problems in adult sexual life and improve overall health.

Ferraz MR ，Cavalheira MA ，Macena de Santana AO ，Barboza VN ，da Silva Nântua M ，Santos LN ，Pereira S ... -  《-》

Complex pattern of interaction between in utero hypoxia-ischemia and intra-amniotic inflammation disrupts brain development and motor function.

Jantzie LL ，Corbett CJ ，Berglass J ，Firl DJ ，Flores J ，Mannix R ，Robinson S ... -  《Journal of Neuroinflammation》

Neonatal erythropoietin mitigates impaired gait, social interaction and diffusion tensor imaging abnormalities in a rat model of prenatal brain injury.

Children who are born preterm are at risk for encephalopathy of prematurity, a leading cause of cerebral palsy, cognitive delay and behavioral disorders. Current interventions are limited and none have been shown to reverse cognitive and behavioral impairments, a primary determinant of poor quality of life for these children. Moreover, the mechanisms of perinatal brain injury that result in functional deficits and imaging abnormalities in the mature brain are poorly defined, limiting the potential to target interventions to those who may benefit most. To determine whether impairments are reversible after a prenatal insult, we investigated a spectrum of functional deficits and diffusion tensor imaging (DTI) abnormalities in young adult animals. We hypothesized that prenatal transient systemic hypoxia-ischemia (TSHI) would induce multiple functional deficits concomitant with reduced microstructural white and gray matter integrity, and tested whether these abnormalities could be ameliorated using postnatal erythropoietin (EPO), an emerging neurorestorative intervention. On embryonic day 18 uterine arteries were transiently occluded for 60min via laparotomy. Shams underwent anesthesia and laparotomy for 60min. Pups were born and TSHI pups were randomized to receive EPO or vehicle via intraperitoneal injection on postnatal days 1 to 5. Gait, social interaction, olfaction and open field testing was performed from postnatal day 25-35 before brains underwent ex vivo DTI to measure fractional anisotropy, axial diffusivity and radial diffusivity. Prenatal TSHI injury causes hyperactivity, impaired gait and poor social interaction in young adult rats that mimic the spectrum of deficits observed in children born preterm. Collectively, these data show for the first time in a model of encephalopathy of prematurity that postnatal EPO treatment mitigates impairments in social interaction, in addition to gait deficits. EPO also normalizes TSHI-induced microstructural abnormalities in fractional anisotropy and radial diffusivity in multiple regions, consistent with improved structural integrity and recovery of myelination. Taken together, these results show behavioral and memory deficits from perinatal brain injury are reversible. Furthermore, resolution of DTI abnormalities may predict responsiveness to emerging interventions, and serve as a biomarker of CNS injury and recovery.

Robinson S ，Corbett CJ ，Winer JL ，Chan LAS ，Maxwell JR ，Anstine CV ，Yellowhair TR ，Andrews NA ，Yang Y ，Sillerud LO ，Jantzie LL ... -  《-》

Dissociation in the Effects of Induced Neonatal Hypoxia-Ischemia on Rapid Auditory Processing and Spatial Working Memory in Male Rats.

Infants born prematurely are at risk for cardiovascular events causing hypoxia-ischemia (HI; reduced blood and oxygen to the brain). HI in turn can cause neuropathology, though patterns of damage are sometimes diffuse and often highly variable (with clinical heterogeneity further magnified by rapid development). As a result, though HI injury is associated with long-term behavioral and cognitive impairments in general, pathology indices for specific infants can provide only limited insight into individual prognosis. The current paper addresses this important clinical issue using a rat model that simulates unilateral HI in a late preterm infant coupled with long-term behavioral evaluation in two processing domains - auditory discrimination and spatial learning/memory. We examined the following: (1) whether deficits on one task would predict deficits on the other (suggesting that subjects with more severe injury perform worse across all cognitive domains) or (2) whether domain-specific outcomes among HI-injured subjects would be uncorrelated (suggesting differential damage to orthogonal neural systems). All animals (sham and HI) received initial auditory testing and were assigned to additional auditory testing (group A) or spatial maze testing (group B). This allowed within-task (group A) and between-task (group B) correlation. Anatomic measures of cortical, hippocampal and ventricular volume (indexing HI damage) were also obtained and correlated against behavioral measures. Results showed that auditory discrimination in the juvenile period was not correlated with spatial working memory in adulthood (group B) in either sham or HI rats. Conversely, early auditory processing performance for group A HI animals significantly predicted auditory deficits in adulthood (p = 0.05; no correlation in shams). Anatomic data also revealed significant relationships between the volumes of different brain areas within both HI and shams, but anatomic measures did not correlate with any behavioral measure in the HI group (though we saw a hippocampal/spatial correlation in shams, in the expected direction). Overall, current data provide an impetus to enhance tools for characterizing individual HI-related pathology in neonates, which could provide more accurate individual prognoses within specific cognitive/behavioral domains and thus improved patient-specific early interventions.

Smith AL ，Alexander M ，Chrobak JJ ，Rosenkrantz TS ，Fitch RH ... -  《-》