Dbx1 Precursor Cells Are a Source of Inspiratory XII Premotoneurons.

All behaviors require coordinated activation of motoneurons from central command and premotor networks. The genetic identities of premotoneurons providing behaviorally relevant excitation to any pool of respiratory motoneurons remain unknown. Recently, we established in vitro that Dbx1-derived pre-Bo¨ tzinger complex neurons are critical for rhythm generation and that a subpopulation serves a premotor function (Wang et al., 2014). Here, we further show that a subpopulation of Dbx1-derived intermediate reticular (IRt) neurons are rhythmically active during inspiration and project to the hypoglossal (XII) nucleus that contains motoneurons important for maintaining airway patency. Laser ablation of Dbx1 IRt neurons, 57% of which are glutamatergic, decreased ipsilateral inspiratory motor output without affecting frequency. We conclude that a subset of Dbx1 IRt neurons is a source of premotor excitatory drive, contributing to the inspiratory behavior of XII motoneurons, as well as a key component of the airway control network whose dysfunction contributes to sleep apnea

Intense Synaptic Activity Enhances Temporal Resolution in Spinal Motoneurons

In neurons, spike timing is determined by integration of synaptic potentials in delicate concert with intrinsic properties. Although the integration time is functionally crucial, it remains elusive during network activity. While mechanisms of rapid processing are well documented in sensory systems, agility in motor systems has received little attention. Here we analyze how intense synaptic activity affects integration time in spinal motoneurons during functional motor activity and report a 10-fold decrease. As a result, action potentials can only be predicted from the membrane potential within 10 ms of their occurrence and detected for less than 10 ms after their occurrence. Being shorter than the average inter-spike interval, the AHP has little effect on integration time and spike timing, which instead is entirely determined by fluctuations in membrane potential caused by the barrage of inhibitory and excitatory synaptic activity. By shortening the effective integration time, this intense synaptic input may serve to facilitate the generation of rapid changes in movements

Simulation Review

PSYCHE-PATHS, $2.98, KMS Industries, Inc., Scientific Games Division, Ann Arbor, Michigan. 1968. Available through book and game sellers. During the week from October 16 to October 23, 1970, Julia Shea's sixth-grade class at Wylie Middle School in Dexter, Michigan, played Psyche-paths. The week prior, 4 of these students had been among the 27 from Wylie who had competed in an Equations tournament in nearby Ann Arbor, and they had won. Mrs. Shea's students are sophisticated game players. All of them have access to chess, Equations, Probe, On-Sets, Eurocard, Nim, Perquacky, and Clue, as well as games they create whenever their regular assignments are finished. They play for fun and they play to learn, and we wanted their reaction to Psyche-paths.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68407/2/10.1177_003755007122009.pd

Rhetorical motives of identity, consubstantiality, and hierarchy: An analysis of community college program documents

The dissertation focuses on three academic programs at Tarrant County College, Northeast Campus, specifically the documents used to create and sustain these programs. The purpose of this study includes the following: first, to identify the terminology specific to each program and/or the documents used within the program; second and third to determine how the terminology creates identity and community for the Community College student and for the college; finally, to determine the rhetorical aspects of kairos, ethos, logos , and pathos of the documents as they apply to the communication between the community college and the students they address. The methodology employed for this research was based on Kenneth Burke's theory of motives in which a careful understanding of word selection, document design and purpose, and target audience is key in analyzing motive and function of the documents in question. Primary archival documents for the Cornerstone Program were used as well as handouts, brochures, and the TCC mission statement to conduct a rhetorical analysis of content and design in order to understand the identity and hierarchy established between the college and the student population. The conclusions of this dissertation suggest that the discourse between administrative documents and public documents is not always clear. Purpose and audience must occasionally be inferred. Further studies should be done quantitatively to determine the effectiveness of the documents for student success. Data is being collected for the Cornerstone and ACCESS programs at TCC and other programs like them at other colleges regarding student success. Data, however, is linked to student success and numbers of attrition and retention but not on how the program literature is influential in the outcomes. Further research needs to be conducted in this area to understand the impact on student success of the discourse between the community groups. At the time of this study, the ACCESS program is just beginning and documents are being generated as the program progresses. Likewise, as the Cornerstone program continues to evolve to address student needs, more artifacts are being generated. Therefore, a final suggestion is to monitor these artifacts in relationship to the original intent of the programs as they pertain to the changing needs and demographics of the student populations they target to ensure that the dialogue reflects the needs and goals of both administration and students alike. Surveys, interviews, and program data collection will be necessary to adequately determine the effectiveness of the TCC programs studied