Functional and motor neuronal analysis of defensive siphon responses in {\it Aplysia californica}

One of the central goals of neuroscience research is to determine how networks of neurons control and modify behavior. One of the most influential model systems for this kind of analysis is the siphon and gill withdrawal reflex of the marine mollusc A. californica. In response to tactile stimulation, the siphon displays 3 different responses: (1) a posterior pointing and leveling (flaring) of the siphon in response to tail stimulation (the siphon T response), (2) constriction and anterior pointing to head stimulation (the siphon H response) and (3) constriction and withdrawal between the animal's parapodia (the siphon S response). The siphon S response is pseudoconditioned by a noxious tail stimulus to resemble the siphon T response. Behavioral and combined behavioral/intracellular studies were conducted to determine the motor neuronal control of these behaviors and to search for mechanisms of siphon response transformation following pseudoconditioning. The present studies have found that the flaring component of pseudoconditioned siphon S responses occurs during mantle pumping (MP) triggered by noxious tail stimulation. Siphon stimulation also triggers MP, as recorded in neurons of the Interneuron II pattern generator which commands MP. The 4 LF$\rm\sb{SB}$ siphon motor neurons (SMNs) were found necessary and sufficient for the siphon T response, while SMNs RD$\rm\sb S$ and LD$\rm\sb{S1}$ were found necessary and sufficient for the siphon H response. Following pseudoconditioning, there is an increase in the number of evoked spikes to the test stimulus for the LF$\rm\sb{SB}$ cells and a decreased number for RD$\rm\sb S.$ Siphon flaring occurring during the pseudoconditioned response correlates with increased LF$\rm\sb{SB}$ activity during triggered MP cycles. This suggests that psuedoconditioning is in part due to reconfiguration of the motor outputs of the Interneuron II network. These results suggest that these defensive responses are controlled and patterned by a well-defined, finite set of motor neurons and interneurons (Interneuron II) that are dedicated to specific behavioral functions, but also have parallel distributed properties. ^

Addressing teenage pregnancy in rural areas: A case study from Liberty County, Texas

This study explores the issue of teenage pregnancy in a case study of Liberty County, a rural area in Texas with no public health department. It also describes the decision-making process and barriers faced in the beginning phases of adopting a sexual education program, and sets forth an implementation plan for two school districts on disseminating an evidence-based, comprehensive curriculum. Methods include a review of epidemiological data surrounding teenage pregnancy on the national, state, and county level; a literature review of factors related to teenage pregnancy and past interventions implemented in a rural community; a policy review of past and current bills in Legislature; and an analysis of barriers and decision making in implementing an evidence based program through qualitative observations, discussions with community members during meetings, presentations, and discussions. Results of this study indicate that there is a lack of research conducted in rural areas in the field of teenage pregnancy prevention and sexual education programs. Barriers experienced in Liberty County are shown to be consistent in scientific literature such as funding, logistical issues, and problems approaching the School Board in adopting a comprehensive sexual education program. This study fills a large gap in the literature on rural adolescents and attempts to analyze the process of decision-making in a rural area related to adoption of sexual education programming. In order to relieve this health disparity, further research should focus on rural areas to gain insight on the attitudes and behaviors of rural adolescents and beliefs among community stakeholders.^