Context-dependent activation of a social behavior brain network associates with learned vocal production.

In zebra finches, an avian brain network for vocal control undergoes context-dependent patterning of song-dependent activation. Previous studies in zebra finches also implicate the importance of dopaminergic input in producing context-appropriate singing behavior. In mice, it has been shown that oxytocinergic neurons originated in the paraventricular nucleus of the hypothalamus (PVN) synapse directly onto dopamine neurons in the ventral tegmental area (VTA), implicating the necessity of oxytocin signaling from the PVN for producing a context-appropriate song. Both avian and non-avian axonal tract-tracing studies indicate high levels of PVN innervation by the social behavior network. Here, we hypothesize that the motivation for PVN oxytocin neurons to trigger dopamine release originates in the social behavior network, a highly conserved and interconnected collection of six regions implicated in various social and homeostatic behaviors. We found that expression of the neuronal activity marker EGR1 was not strongly correlated with song production in any of the regions of the social behavior network. However, when EGR1 expression levels were normalized to the singing rate, we found significantly higher levels of expression in the social behavior network regions except the medial preoptic area during a social female-directed singing context compared to a non-social undirected singing context. Our results suggest neuronal activity within the male zebra finch social behavior network influences the synaptic release of oxytocin from PVN onto dopaminergic projection neurons in the VTA, which in turn signals to the vocal control network to allow for context-appropriate song production.

Context-dependent activation of a social behavior brain network during learned vocal production.

Neural activation in brain regions for vocal control is social context dependent. This context-dependent brain activation reflects social context-appropriate vocal behavior but has unresolved mechanisms. Studies of non-vocal social behaviors in multiple organisms suggest a functional role for several evolutionarily conserved and highly interconnected brain regions. Here, we use neural activity-dependent gene expression to evaluate the functional connectivity of this social behavior network within zebra finches in non-social and social singing contexts. We found that activity in one social behavior network region, the medial preoptic area (POM), was strongly associated with the amount of non-social undirected singing in zebra finches. In addition, in all regions of the social behavior network and the paraventricular nucleus (PVN), a higher percentage of EGR1 expression was observed during a social female-directed singing context compared to a non-social undirected singing context. Furthermore, we observed distinct patterns of significantly correlated activity between regions of the social behavior network during non-social undirected and social female-directed singing. Our results suggest that non-social vs. social contexts differentially activate this social behavior network and PVN. Moreover, neuronal activity within this social behavior network, PVN, and POM may alter context-appropriate vocal production.

Searching for the self: an identity control theory approach to triggers of occupational exploration.

Identity control theory researchers have found evidence for two processes of identity development (identity defense and identity change) and have theorized a third process (identity exploration). College students (N = 123) self-rated as high or low in occupational identity certainty and importance received self-discrepant feedback to induce identity disturbance, and dependent measures of identity defense, identity change, and identity exploration were obtained. As predicted, high certainty about identity standards led to identity defense, while low certainty led to identity change. Although an interaction between certainty and importance was hypothesized to predict identity exploration, results showed that the two operated independently. Low certainty predicted exploration of additional occupational areas, whereas high importance predicted exploration of self, environment, and additional occupational areas.

Evaluating an inclusive trauma system using linked population-based data.

BACKGROUND: Federal and professional programs require "inclusive" trauma systems. We wished to evaluate an inclusive trauma system using administrative data combined from multiple sources. METHODS: Ambulance reports, outpatient/inpatient discharge data, and/or death certificates were obtained for persons with injury diagnoses who received hospital services and/or died in Maine during 1998 to 2000. Records were unduplicated and joined using probabilistic record-linkage software. Case outcomes, determined from one or more linked records, included place of hospitalization, discharge status, and 30-day mortality. RESULTS: Per 100,000 population annually, 11,100 injured persons were treated and released, 573 were admitted, and 51.3 died. Trauma centers received 37.0% of major cases directly and another 15.4% in transfer; 51.4% of injury deaths occurred without medical intervention, 21.2% occurred in trauma centers, 20.4% occurred in other hospitals, and 7.0% occurred after discharge from a hospital. Database queries produced comparative hospital statistics and identification of questionable outcomes. CONCLUSION: Record linkage allows inexpensive description of an inclusive trauma system and may contribute to quality improvement.