Does puberty mark a transition in sensitive periods for plasticity in the associative neocortex?

Postnatal brain development is studded with sensitive periods during which experience dependent plasticity is enhanced. This enables rapid learning from environmental inputs and reorganization of cortical circuits that matches behavior with environmental contingencies. Significant headway has been achieved in characterizing and understanding sensitive period biology in primary sensory cortices, but relatively little is known about sensitive period biology in associative neocortex. One possible mediator is the onset of puberty, which marks the transition to adolescence, when animals shift their behavior toward gaining independence and exploring their social world. Puberty onset correlates with reduced behavioral plasticity in some domains and enhanced plasticity in others, and therefore may drive the transition from juvenile to adolescent brain function. Pubertal onset is also occurring earlier in developed nations, particularly in unserved populations, and earlier puberty is associated with vulnerability for substance use, depression and anxiety. In the present article we review the evidence that supports a causal role for puberty in developmental changes in the function and neurobiology of the associative neocortex. We also propose a model for how pubertal hormones may regulate sensitive period plasticity in associative neocortex. We conclude that the evidence suggests puberty onset may play a causal role in some aspects of associative neocortical development, but that further research that manipulates puberty and measures gonadal hormones is required. We argue that further work of this kind is urgently needed to determine how earlier puberty may negatively impact human health and learning potential. This article is part of a Special Issue entitled SI: Adolescent plasticity.

Adolescent development of inhibition as a function of SES and gender: Converging evidence from behavior and fMRI

The ability to adaptively inhibit responses to tempting/distracting stimuli in the pursuit of goals is an essential set of skills necessary for adult competence and wellbeing. These inhibitory capacities develop throughout childhood, with growing evidence of important maturational changes occurring in adolescence. There also has been intense interest in the role of social adversity on the development of executive function, including inhibitory control. We hypothesized that the onset of adolescence could be a time of particular opportunity/vulnerability in the development of inhibition due to the large degree of maturational changes in neural systems involved in regulatory control. We investigated this hypothesis in a longitudinal study of adolescents by examining the impact of socioeconomic status (SES) on the maturation of inhibition and concurrent brain function. Furthermore, we examined gender as a potential moderator of this relationship, given evidence of gender-specificity in the developmental pathways of inhibition as well as sex differences in adolescent development. Results reveal that lower SES is associated with worse behavioral inhibition over time and a concurrent increase in anterior cingulate (ACC) activation, but only in girls. We also found that lower SES girls exhibited decreased ACC ↔ dorsolateral prefrontal cortex (dlPFC) coupling over time. Our findings suggest that female adolescents with lower SES appear to develop less efficient inhibitory processing in dlPFC, requiring greater and relatively unsuccessful compensatory recruitment of ACC. In summary, the present study provides a novel window into the neural mechanisms by which the influence of SES on inhibition may be transmitted during adolescence.

Crisis communication: an inequalities perspective on the 2010 Boston water crisis

OBJECTIVE

Although the field of crisis risk communication has generated substantial research, the interaction between social determinants, communication processes, and behavioral compliance has been less well studied. With the goal of better understanding these interactions, this report examines how social determinants influenced communications and behavioral compliance during the 2010 Boston, Massachusetts, water crisis.

METHODS

An online survey was conducted to assess Boston residents' knowledge, beliefs, attitudes, mass and interpersonal communication, and preventive behaviors on emergency preparedness topics dealing with the water crisis. Of a total sample of 726 respondents, approximately one-third (n = 267) reported having been affected by the water crisis. Only data from affected participants were analyzed.

RESULTS

Following an order to boil water, 87.5% of respondents refrained from drinking unboiled tap water. These behaviors and other cognitive and attitudinal factors, however, were not uniform across population subgroups. All communication and behavioral compliance variables varied across sociodemographic factors.

CONCLUSIONS

Crisis communication, in conjunction with other public health preparedness fields, is central to reducing the negative impact of sudden hazards. Emergency scenarios such as the Boston water crisis serve as unique opportunities to understand how effectively crisis messages are conveyed to and received by different segments of the population.

Message formats and their influence on perceived risks of tobacco use: a pilot formative research project in India

In India, tobacco kills 900,000 people every year though the burden of tobacco is faced disproportionately in poorer states such as Bihar. Teachers may be a particularly influential group in setting norms around tobacco use in the Indian context. However, tobacco use among teachers remains high and perceptions of tobacco-related health risks are unexplored. To qualitatively explore perceptions about tobacco use among teachers in Bihar and to examine how risk information may be communicated through a variety of message formats, 12 messages on tobacco health risks varying in formats were tested in focus groups with teachers from Bihar. Participants stated that teachers were already aware of tobacco-related health risks. To further increase awareness of these risks, the inclusion of evidence-based facts in messages was recommended. Communicating risk information using negative emotions had a great appeal to teachers and was deemed most effective for increasing risk perception. Messages using narratives of teachers' personal accounts of quitting tobacco were deemed effective for increasing knowledge about the benefits of quitting. To conclude, messages using evidence-based information, possibly with negative emotions, testimonials with role models and those messages emphasizing self-efficacy in the format of narratives appear to appeal to teachers in Bihar.

Class, race, ethnicity and information needs in post-treatment cancer patients

OBJECTIVE

Health information-seeking behaviors (HISBs) are associated with active participation in cancer care decisions which, in turn, may positively impact health outcomes. The goal of this study was to develop a taxonomy of topics for which post-treatment cancer patients sought information, and to explore HISB patterns by sociodemographic factors and cancer type.

METHODS

We examined how health information seeking is associated with social determinants in a survey of 521 post-treatment cancer patients.

RESULTS

Four major topics of interest were found: disease/treatment, self-care management, health services, and work/finance. Assessment of the relationship between social determinants and these four topics showed associations for (1) HISBs on disease/treatment topics decreased with age and increased with education; (2) HISBs on self-care management increased with education and varied by cancer type; (3) HISBs on health services increased with education; and (4) HISBs on work/finance decreased with age and wealth, but increased with debt.

CONCLUSION

These results demonstrate one pathway through which social determinants may drive communication inequalities, which may result in increased disparities in health outcomes.

PRACTICE IMPLICATIONS

Further exploration of the relationship between social determinants and information-seeking among post-treatment cancer patients may contribute to the development of strategies to reduce health disparities.

Socioeconomic status, demographics, beliefs and A(H1N1) vaccine uptake in the United States

Early vaccination against influenza viruses is a cost-effective solution to prevent contagion and reduce influenza-related morbidity and mortality. In the face of pandemic viruses, such as the A(H1N1), adequate rates of vaccine uptake play a critical role in containing the spread and effects of the disease. In order to understand the reasons underlying the relatively low 2009-2010 A(H1N1) vaccination rates, we conducted an online survey of 1569 respondents drawn from a nationally representative sample of United States (U.S.) adults age 18, and older. Because prior research suggests that vaccination rates are especially low among some U.S. population subgroups, we oversampled participants from minority ethnic/racial groups and those living under the Federal Poverty Level. Our results show that A(H1N1) vaccine uptake is associated with sociodemographic factors, A(H1N1)-related beliefs and seasonal vaccination. That is, A(H1N1) vaccination is strongly associated with age, urbanicity, perceiving the A(H1N1) vaccine as safe and seasonal flu vaccine uptake. Perceptions of safety and season flu vaccination show the strongest associations with A(H1N1) uptake. The reasons people gave to decline vaccination varied by respondents' sociodemographic group. For example, Black participants were the most likely ethnic/racial group to reported having tried to get the vaccine but found it unavailable. Together, these findings suggest some clear pointers towards strategic public health communication efforts calling for communication campaigns towards audiences segmented by social class, race/ethnicity and beliefs, often what advertisers call "psychodemographics".

Socioeconomic status, demographics, beliefs and A(H1N1) vaccine uptake in the United States

Early vaccination against influenza viruses is a cost-effective solution to prevent contagion and reduce influenza-related morbidity and mortality. In the face of pandemic viruses, such as the A(H1N1), adequate rates of vaccine uptake play a critical role in containing the spread and effects of the disease. In order to understand the reasons underlying the relatively low 2009-2010 A(H1N1) vaccination rates, we conducted an online survey of 1569 respondents drawn from a nationally representative sample of United States (U.S.) adults age 18, and older. Because prior research suggests that vaccination rates are especially low among some U.S. population subgroups, we oversampled participants from minority ethnic/racial groups and those living under the Federal Poverty Level. Our results show that A(H1N1) vaccine uptake is associated with sociodemographic factors, A(H1N1)-related beliefs and seasonal vaccination. That is, A(H1N1) vaccination is strongly associated with age, urbanicity, perceiving the A(H1N1) vaccine as safe and seasonal flu vaccine uptake. Perceptions of safety and season flu vaccination show the strongest associations with A(H1N1) uptake. The reasons people gave to decline vaccination varied by respondents' sociodemographic group. For example, Black participants were the most likely ethnic/racial group to reported having tried to get the vaccine but found it unavailable. Together, these findings suggest some clear pointers towards strategic public health communication efforts calling for communication campaigns towards audiences segmented by social class, race/ethnicity and beliefs, often what advertisers call "psychodemographics".

Measuring Pavlovian fear with conditioned freezing and conditioned suppression reveals different roles for the basolateral amygdala

In Pavlovian fear conditioning, pairing a neutral cue with aversive foot shock endows a cue with fear-eliciting properties. Studies of Pavlovian fear conditioning measuring freezing have demonstrated the basolateral amygdala (BLA) to be critical to both fear learning and memory. The nucleus accumbens core (NAc), while not important to freezing, is important to the enhancement of instrumental responding by cues paired with food reward. In the present study we investigated the role of the BLA and the NAc in another property of fear cues, the ability to suppress instrumental responding for food rewards (conditioned suppression). Sham, BLA and NAc-lesioned rats received a fear discrimination procedure in which one visual cue (CS+) predicted foot shock while a second cue (CS-) did not. Conditioning took place over a baseline of instrumental responding, allowing for concurrent measure of freezing and instrumental suppression. NAc lesions left fear conditioning fully intact. BLA lesions impaired acquisition and discrimination of fear when assessed with conditioned freezing. However, BLA lesions only altered fear acquisition and left discrimination completely intact when assessed with conditioned suppression. These findings suggest a critical role for the BLA in fear when assessed with conditioned freezing but a diminished role when assessed with conditioned suppression.

The basolateral amygdala mediates the effects of cues associated with meal interruption on feeding behavior

Considerable evidence shows that environmental cues that signal food delivery when rats are food-deprived can substantially potentiate feeding later when rats are food-sated. Similarly, cues associated with meal interruption, food removal or impending food scarcity may also induce increased eating. For example, after learning the association between a discrete "interruption" stimulus and the unexpected termination of food trials, sated rats show enhanced food consumption when exposed to that stimulus. In Experiment 1, unlike sham-lesioned controls, rats with bilateral excitotoxic lesions of the basolateral amygdala (BLA) failed to display such cue-potentiated feeding. In Experiment 2, potentiation of feeding by an interruption signal was found to be food-specific. That is, a stimulus that signaled interruption of trials with one food but not trials with a second food later only facilitated consumption of the first food. These studies extend our knowledge of the psychological and neural processes underlying cue-induced feeding. Understanding these mechanisms may contribute our understanding of the etiology and treatment of binge eating disorders.

Effects of cues associated with meal interruption on feeding behavior

Food consumption is controlled by both internal and external factors. Environmental signals associated with food may prepare an animal to forage, consume and digest more effectively. Furthermore, environmental cues that provide information about food availability enable animals to make predictions about future food resources and act upon that knowledge in appropriate fashion. For example, when exposed to a cue that signals the presence of food, animals can eat beyond their present needs to cope with predicted future famine. Interestingly, cues previously paired with meal interruption have a similar effect. In two experiments, food-deprived rats learned to associate one conditioned stimulus (CS+) with delivery of a food unconditioned stimulus (US), and another stimulus (IS) with an unexpected termination of CS-US trials. Subsequently, both CS+ and IS enhanced consumption of the US food by sated rats. The results of Experiment 2 indicated that IS's ability to potentiate feeding of sated rats in test depended more on its accompanying CS+ termination in training than on its signaling reductions in US frequency. These experiments may provide a novel animal model of binge-like behaviors in sated rats induced by external cues paired with meal interruption.

Reinforcer-specificity of appetitive and consummatory behavior of rats after Pavlovian conditioning with food reinforcers

We examined the reinforcer-specificity of Pavlovian conditioning in the control of appetitive and consummatory behaviors in Pavlovian-to-instrumental transfer, cue-potentiated eating, and devaluation procedures. Rats received pairings of one conditioned stimulus with sucrose and another conditioned stimulus with maltodextrin. In Experiment 1, rats were also trained to earn sucrose for one instrumental response and maltodextrin for another. In a transfer test, the Pavlovian cues enhanced the rate of instrumental responding more when the food reinforcer predicted by the instrumental response and the Pavlovian cue were consistent than when they were inconsistent, but both cues enhanced both responses. In Experiment 2, sated rats' consumption of each food was potentiated in the presence of a cue for that food, but not in the presence of a cue for the other food. In Experiment 3, one food was devalued by pairing it with lithium chloride, prior to testing food consumption and food-cup directed behaviors. The food cues selectively controlled food-cup related behaviors, regardless of the presence of the devalued or nondevalued foods in the food cup. Together, these results are consistent with the view that conditioned cues modulate appetitive and consummatory behaviors with increasing levels of specificity. The closer an action comes to ingestion, the more it is controlled by sensory properties conveyed by learned cues. These data are discussed in the context of allostatic regulation of food foraging and intake.