A significant fraction of infants born to mothers taking selective serotonin reuptake inhibitors (SSRIs) during late pregnancy display clear signs of antidepressant withdrawal indicating that these drugs can penetrate fetal brain in utero at biologically significant levels. Previous studies in rodents have demonstrated that early exposure to some antidepressants can result in persistent abnormalities in adult behavior and indices of monoaminergic activity. Here, we show that chronic neonatal (postnatal days 8-21) exposure to citalopram (5 mg/kg, twice daily, s.c.), a potent and highly selective SSRI, results in profound reductions in both the rate-limiting serotonin synthetic enzyme (tryptophan hydroxylase) in dorsal raphe and in serotonin transporter expression in cortex that persist into adulthood. Furthermore, neonatal exposure to citalopram produces selective changes in behavior in adult rats including increased locomotor activity and decreased sexual behavior similar to that previously reported for antidepressants that are nonselective monoamine transport inhibitors. These data indicate that the previously reported neurobehavioral effects of antidepressants are a consequence of their effects on the serotonin transporter. Moreover, these data argue that exposure to SSRIs at an early age can disrupt the normal maturation of the serotonin system and alter serotonin-dependent neuronal processes. It is not known whether this effect of SSRIs is paralleled in humans; however, these data suggest that in utero, exposure to SSRIs may have unforeseen long-term neurobehavioral consequences.

Steroidogenic factor 1 (SF-1) is an orphan nuclear receptor that serves as an essential regulator of many hormone-induced genes in the vertebrate endocrine system. The apparent absence of a SF-1 ligand prompted speculation that this receptor is regulated by alternative mechanisms involving signal transduction pathways. Here we show that maximal SF-1-mediated transcription and interaction with general nuclear receptor cofactors depends on phosphorylation of a single serine residue (Ser-203) located in a major activation domain (AF-1) of the protein. Moreover, phosphorylation-dependent SF-1 activation is likely mediated by the mitogen-activated protein kinase (MAPK) signaling pathway. We propose that this single modification of SF-1 and the subsequent recruitment of nuclear receptor cofactors couple extracellular signals to steroid and peptide hormone synthesis, thereby maintaining dynamic homeostatic responses in stress and reproduction.

Serotonin (5-HT) plays a key role in early brain development, and manipulation of 5-HT levels during this period can have lasting neurobiological and behavioral consequences. It is unclear how perinatal exposure to drugs, such as selective serotonin reuptake inhibitors (SSRIs), impacts cortical neural network function and what mechanism(s) may elicit the disruption of normal neuronal connections/interactions. In this article, we report on cortical wiring organization after pre-and postnatal exposure to the SSRI citalopram. We show that manipulation of 5-HT during early development in both in vitro and in vivo models disturbs characteristic chemoarchitectural and electrophysiological brain features, including changes in raphe and callosal connections, sensory processing, and myelin sheath formation. Also, drug-exposed rat pups exhibit neophobia and disrupted juvenile play behavior. These findings indicate that 5-HT homeostasis is required for proper brain maturation and that fetal/infant exposure to SSRIs should be examined in humans, particularly those with developmental dysfunction, such as autism.S erotonin (5-HT) has long been postulated to play a trophic role in brain morphogenesis, including cell proliferation, migration, and differentiation. It is also known to be one of the first neurotransmitters to appear in the central nervous system (1, 2). An obvious question that can be raised relates to whether perinatal exposure to antidepressants, such as selective serotonin reuptake inhibitors (SSRIs), can affect cortical circuit development and function. Perhaps one of the most intriguing previous findings related to 5-HT and early cortical organization was the observation from immunohistochemical and 5-HT transporter (SERT) binding studies that, at postnatal days 2-14 (P2-P14), rodent primary sensory cortex (notably layer IV of visual, auditory, and somatosensory areas) is transiently innervated by aggregates of fine grainlooking 5-HT-containing processes (3)(4)(5). Surprisingly, it became clear that, in early brain development, 5-HT is taken up into glutamatergic thalamocortical terminals (6, 7) and used in combination with the 5-HT 1B receptor on layer IV afferents (8). At present, the functional implication of such transient 5-HT expression and targeting, namely the primary sensory thalamocortical afferents during early development, remains unknown.5-HT and Abnormal Brain Development. Interestingly, manipulations of rodent brain 5-HT levels during early development, either through increases (produced in SERT or monoamine oxidase knockout mice) or decreases (produced by parachlorophenylalanine or other treatments), have been shown to produce the downstream effect of interfering with the formation of the whisker (barrel) representation in the primary somatosensory cortex and promoting aggressive and/or anxiety-related behaviors (9-14). Furthermore, early-life modification of 5-HT levels has been shown to cause overreaction to auditory or tactile sensory stimulation (15) and abnormal response properties of cor...

Cognitive decline is a virtually universal aspect of the aging process. However, its neurophysiological basis remains poorly understood. We describe here more than 20 age-related cortical processing deficits in the primary auditory cortex of aging versus young rats that appear to be strongly contributed to by altered cortical inhibition. Consistent with these changes, we recorded in old rats a decrease in parvalbuminlabeled inhibitory cortical neurons. Furthermore, old rats were slower to master a simple behavior, with learning progressions marked by more false-positive responses. We then examined the effect of intensive auditory training on the primary auditory cortex in these aged rats by using an oddball discrimination task. Following training, we found a nearly complete reversal of the majority of previously observed functional and structural cortical impairments. These findings suggest that age-related cognitive decline is a tightly regulated plastic process, and demonstrate that most of these age-related changes are, by their fundamental nature, reversible. aging | cognitive decline | plasticity | inhibition | parvalbumin P erceptual and cognitive decline are near-universal aspects of normal aging (1, 2). Such deficits cannot be explained solely by a dysfunction of peripheral sensory organs and frequently translate to slowed perceptual processing and difficulty in accurately identifying stimuli under challenging (e.g., noisy, time-limited, attentionally demanding) conditions (3, 4). In the human auditory system, psychophysical and electroencephalography experiments have examined aspects of cognitive decline by using oddball detection paradigms, successive-signal masking studies, speech-in-noise studies, and compressed speech (5-7), among other strategies. These studies have shown that degraded signal salience, defective sensory adaptation and a slowing of sensory processing contribute to the deterioration of a wide range of perceptual and cognitive processes recorded in aged populations (3,(8)(9)(10). Animal models have been instrumental in defining the cellular and molecular basis of agerelated perceptual impairments. In rats, significant alterations in inhibitory function in various subcortical nuclei and the auditory cortex have been linked to abnormal temporal and spectral processing (11)(12)(13)(14). Interestingly, although these changes are often described as progressive plastic compensations secondary to a combination of slow peripheral deafferentation and chemical or molecular insults (11,15), the possibility that age-related changes might be by their plastic nature largely reversible has seldom been explored or proposed (16). Compelling evidence that these agerelated functional alterations can be prevented to some extent by sensory enrichment (9, 17) or even dietary improvements (15) certainly supports this concept. During adulthood, after the closure of developmental plasticity windows, attention-demanding intensive training strategies remain one of the most powerful means of directing plastic re...

IMPORTANCE Pay for performance is intended to align incentives to promote high-quality care, but results have been contradictory.OBJECTIVE To test the effect of explicit financial incentives to reward guidelinerecommended hypertension care. DESIGN, SETTING, AND PARTICIPANTSCluster randomized trial of 12 Veterans Affairs outpatient clinics with 5 performance periods and a 12-month washout that enrolled 83 primary care physicians and 42 nonphysician personnel (eg, nurses, pharmacists).INTERVENTIONS Physician-level (individual) incentives, practice-level incentives, both, or none. Intervention participants received up to 5 payments every 4 months; all participants could access feedback reports.MAIN OUTCOMES AND MEASURES Among a random sample, number of patients achieving guideline-recommended blood pressure thresholds or receiving an appropriate response to uncontrolled blood pressure, number of patients prescribed guideline-recommended medications, and number who developed hypotension.

Increasing numbers of students with autism are being educated in mainstream schools. However, outcomes for students with autism are poor when compared to typical students and students with other developmental disabilities. In order to better understand facilitators and barriers to success at school for students with autism, research into the attitudes of key stakeholders, educators, parents, people with autism, to inclusion in mainstream schools for students with autism, was reviewed. Key themes emerging included attitudes to inclusion, the characteristics of autism and social communication in particular and interaction with the school environment, and consequent student problem behaviour. Level of knowledge and understanding of school staff emerged as the primary issue with all stakeholders identifying the need for more training. Other support needs identified included the need for structural support, resources and funding. Parents, in particular, identified the need for a collaborative approach to the education process. The findings highlight the need to translate theory into practice to increase capacity in schools to provide effective educational programmes for students with autism.

Our previous studies have shown that neonatal exposure to lipopolysaccharide (LPS) resulted in motor dysfunction and dopaminergic neuronal injury in the juvenile rat brain. To further examine whether neonatal LPS exposure has persisting effects in adult rats, motor behaviors were examined from postnatal day 7 (P7) to P70 and brain injury was determined in P70 rats following an intracerebral injection of LPS (1 mg/kg) in P5 Sprague-Dawley male rats. Although neonatal LPS exposure resulted in hyperactivity in locomotion and stereotyped tasks, and other disturbances of motor behaviors, the impaired motor functions were spontaneously recovered by P70. On the other hand, neonatal LPS-induced injury to the dopaminergic system such as the loss of dendrites and reduced tyrosine hydroxylase immunoreactivity in the substantia nigra persisted in P70 rats. Neonatal LPS exposure also resulted in sustained inflammatory responses in the P70 rat brain, as indicated by an increased number of activated microglia and elevation of interleukin-1β and interleukin-6 content in the rat brain. In addition, when challenged with methamphetamine (METH, 0.5 mg/kg) subcutaneously, rats with neonatal LPS exposure had significantly increased responses in METH-induced locomotion and stereotypy behaviors as compared to those without LPS exposure. These results indicate that although neonatal LPSinduced neurobehavioral impairment is spontaneously recoverable, the LPS exposure-induced persistent injury to the dopaminergic system and the chronic inflammation may represent the existence of silent neurotoxicity. Our data further suggest that the compromised dendritic mitochondrial function might contribute, at least partially, to the silent neurotoxicity.

Converging lines of evidence show that a sizable subset of autism-spectrum disorders (ASDs) is characterized by increased blood levels of serotonin (5-hydroxytryptamine, 5-HT), yet the mechanistic link between these two phenomena remains unclear. The enzymatic degradation of brain 5-HT is mainly mediated by monoamine oxidase (MAO)A and, in the absence of this enzyme, by its cognate isoenzyme MAOB. MAOA and A/B knockout (KO) mice display high 5-HT levels, particularly during early developmental stages. Here we show that both mutant lines exhibit numerous behavioural hallmarks of ASDs, such as social and communication impairments, perseverative and stereotypical responses, behavioural inflexibility, as well as subtle tactile and motor deficits. Furthermore, both MAOA and A/B KO mice displayed neuropathological alterations reminiscent of typical ASD features, including reduced thickness of the corpus callosum, increased dendritic arborization of pyramidal neurons in the prefrontal cortex and disrupted microarchitecture of the cerebellum. The severity of repetitive responses and neuropathological aberrances was generally greater in MAOA/B KO animals. These findings suggest that the neurochemical imbalances induced by MAOAdeficiency (either by itself or in conjunction with lack of MAOB) may result in an array of abnormalities similar to those observed in ASDs. Thus, MAOA and A/B KO mice may afford valuable models to help elucidate the neurobiological bases of these disorders and related neurodevelopmental problems.