Dynamic shifts in corticostriatal expression patterns of the immediate early genes Homer 1a and Zif268 during early and late phases of instrumental training

Adaptive motor actions require prior knowledge of instrumental contingencies. With practice, these actions can become highly automatic in nature. However, the molecular and anatomical substrates mediating these related forms of learning are not understood. In the present study, we used in situ hybridization to measure the mRNA levels of two immediate early genes (IEGs) in an instrumental paradigm where rats learned to lever-press for food. We report that after three training sessions, Homer 1a and Zif268 (an effector and regulatory IEG, respectively) were significantly induced within an extensive corticostriatal network relative to untrained controls. With extended training (23 sessions), however, a shift in the expression patterns of the two genes was evident. Expression of Homer 1a (official symbol Homer1) decreased significantly in frontal and cingulate cortices, whereas striatal expression was generally maintained. Interestingly, Homer 1a expression markedly increased with extensive training in the ventrolateral region of the striatum (VLS) relative to early learners, suggesting that plasticity in the VLS is required for the efficient production of the learned behavior or in habit formation. Zif268 (official symbol Egr1) expression generally decreased with extensive training; however, these changes were not significant. These results demonstrate for the first time, on a molecular level, a dynamic shift in the contribution of corticostriatal systems mediating the early acquisition and consolidation of goal-directed responses to those engaged after extensive training.     

Suicidality in African American men: the roles of southern residence, religiosity, and social support

The rise in suicide by African Americans in the United States is directly attributable to the dramatic, nearly three-fold increase in suicide rates of African American males. Gibbs (1997) hypothesized high social support, religiosity, and southern residence are protective factors against suicidality for Black people. This hypothesis was tested among 5,125 participants from the National Comorbidity Survey; 299 were African American males. In this study we hypothesized that there would be significantly lower suicidality in the South, and social support and religiosity would mediate this relationship. Our results indicate that Southern region is indeed a significant predictor of suicidal symptoms in African American men, such that suicidal symptoms were lower in the South, but religiosity and social support did not account for this effect. Other potential mediators were also examined.     

AMPA/kainate, NMDA, and dopamine D1 receptor function in the nucleus accumbens core: a context-limited role in the encoding and consolidation of instrumental memory

Neural integration of glutamate- and dopamine-coded signals within the nucleus accumbens (NAc) is a fundamental process governing cellular plasticity underlying reward-related learning. Intra-NAc core blockade of NMDA or D1 receptors in rats impairs instrumental learning (lever-pressing for sugar pellets), but it is not known during which phase of learning (acquisition or consolidation) these receptors are recruited, nor is it known what role AMPA/kainate receptors have in these processes. Here we show that pre-trial intra-NAc core administration of the NMDA, AMPA/KA, and D1 receptor antagonists AP-5 (1 microg/0.5 microL), LY293558 (0.01 or 0.1 microg/0.5 microL), and SCH23390 (1 microg/0.5 microL), respectively, impaired acquisition of a lever-pressing response, whereas post-trial administration left memory consolidation unaffected. An analysis of the microstructure of behavior while rats were under the influence of these drugs revealed that glutamatergic and dopaminergic signals contribute differentially to critical aspects of the initial, randomly emitted behaviors that enable reinforcement learning. Thus, glutamate and dopamine receptors are activated in a time-limited fashion-only being required while the animals are actively engaged in the learning context.     

Psychological Reactions to the Drunk Driver: Associations With Intervention and Their Success1

Research on psychological factors in helping behavior has been undertaken primarily in laboratory settings. Although this work has been instrumental in identifying psychological factors that influence helping, their role in naturally occurring helping behavior, such as informal drunk-driving intervention, is largely unknown. College students (N= 192) completed a questionnaire that assessed 11 possible reactions to the drunk driving situation, types of interventions, and their success. Over half of the students (55%, N= 10) reported having intervened to prevent someone from driving drunk. Using structural modeling, we examined the effect of various emotions and affective and cognitive reactions on the frequency and success of different types of informal drunk-driving intervention. Different reactions to the drunk driving situation influenced the number, type, and success of interventions used.     

Traumatization of group leaders in their work with displaced persons

Displaced persons are a special, threatened group of people, participants in this war, who were suddenly forced to abandon their homes. The majority of them were, overnight, left without anything they had, some even without their closest family. They all have one thing in common: they have all lost so much. Work with such people is directed toward overcoming their feelings of loss and abandonment and preventing psychical decompensation. Groups of displaced persons temporarily sheltered in the Rijeka region have been observed to be markedly regressed, with increased sensitivity, a low degree of tolerance, great demands on society and strongly expressed projective tendencies. Therapists suffer personal traumatization in working with displaced persons. This paper describes the reactions and feelings of group leaders caused by manifestations of group dynamics in different phases of exile.     

Developing community alternatives to group home placement for SED special education students in the Ventura County System of Care

Interagency planning and resource development were used to improve available services for severely emotionally disturbed special education students who were in or at-risk of being placed in residential care. Augmented local school-based and regional day treatment services were financed by a Ventura County Social Services Agency trust fund and delivered cooperatively by the County Mental Health Agency and local education agencies. Revenues generated by the new service positions were planned to restore the trust fund. Outcomes following service implementation included: (a) an average reduction of 3.5 youths in the expected number of youths in group home placement per month; (b) a total reduction of $290,011 in the expected annual cost of placement; and (c) generation of $281,238 in Medi-Cal revenue by the school-based and day treatment components of the system of care. The implications of these outcomes are discussed in terms of existing trends in numbers of identified seriously emotionally disturbed students and their service needs and the processes that were involved in planning and implementing the service augmentation.     

Informal Drunk Driving Intervention: Psychosocial Correlates Among Young Adult Women and Men1

Based on experimental research on helping and survey findings on drunk driving intervention, we selected 28 variables for study that might relate to informal intervention in a drunk driving situation. We tested six hypotheses by categorizing the 28 variables into personal (12), relationship (4), situational (5), and individual response (7) aspects. Bivariate correlations and multivariate logistic regression analyses were performed between these 28 predictor variables and intervention for 303 college students (192 females and 111 males). Three personal, one relationship, three situational, and four individual responses in situation variables were correlated significantly with intervention. Four significant predictors emerged in the stepwise logistic regression equation: knowing the driver well; having a conversation that encouraged the respondent to intervene; perceiving the driver as needing help; and the respondent's feeling able to intervene. All hypotheses received at least some confirmation in these results, but noteworthy discrepancies from expectations emphasize the need to appreciate differences between studies of helping behavior in the laboratory and this natural form of helping behavior.     

Structural and experiential factors in newborns’ preference for speech sounds

It is well established that newborns prefer some sounds over others. It is widely believed that these preferences reflect past experience, either prenatally or in the immediate postnatal environment. However, it is also possible that structural factors are involved. The frequency of occurrence of different sounds in the languages of the world may provide evidence of such structural factors. If structural factors are important, and if frequency of occurrence of sounds in the world’s languages reflects structural factors, then we might expect newborn preference for sounds to reflect their frequency across languages. In this study, newborns were presented with two cv pairs consisting of a trilled /r/ and a bunched /r/ followed by the vowel //. The newborns were either of English‐speaking or Spanish‐speaking origin. The bunched /r/ occurs in American English and is not frequent in the languages of the world. It does not occur in Spanish. The trilled /r/ occurs in Spanish and is a frequent consonant in the languages of the world. It does not occur in American English. Results showed that newborns of both linguistic backgrounds preferred to listen to the trilled /r/. It is hypothesized that the frequency of occurrence of a sound in the languages of the world may reflect structurally based ease of production and ease of perception, the latter leading to the newborn preference.     

Less exploring by mouth occurs in newborns of depressed mothers

Twenty‐four newborns (M age = 12 days) of depressed and nondepressed mothers were assessed for oral perception of a nubby and smooth texture. Both groups of newborns discriminated between these textures and showed a sucking preference for the smooth texture. However, the newborns of depressed mothers spent 50% less time orally exploring the stimuli, one‐third less time exploring the more novel nubby texture, and 59% less time mouthing the smooth texture. Newborns of depressed mothers may have biological differences that affect their emotional arousal and emotional regulation (e.g., capacity for self‐soothing). © 2000 Michigan Association for Infant Mental Health.