Developmental regulation of GABAergic gene expression in forebrain cholinergic neurons.

Acetylcholine and GABA are often co-released, including from VIP-expressing neurons of the cortex, cortically-projecting neurons of the globus pallidus externus and basal forebrain, and hippocampal-projecting neurons of the medial septum. The co-release of the functionally antagonistic neurotransmitters GABA and acetylcholine (ACh) greatly expands the possible functional effects of cholinergic neurons and provides an additional exogenous source of inhibition to the cortex. Transgene expression suggests that nearly all forebrain cholinergic neurons in mice at some point in development express Slc32a1, which encodes the vesicular GABA transporter (VGAT). To determine the degree of co-expression of GABA and Ach handling proteins, we measured expression in adult mice of Slc32a1, Gad1 and Gad2 (which encode GAD67 and GAD65, respectively, the GABA synthetic enzymes) in cholinergic neurons using fluorescent in situ hybridization. We found that only a subset of cholinergic neurons express the necessary machinery for GABA release at a single time in adult mice. This suggests that GABA co-release from cholinergic neurons is dynamic and potentially developmentally regulated. By measuring expression of Slc32a1, Gad1, Gad2, and Chat in the basal forebrain and medial septum in mice from post-natal day 0 to 28, we noted abundant yet variable expressions of GABAergic markers across early development, which are subsequently downregulated in adulthood. This is in contrast with the forebrain-projecting pedunculopontine nucleus, which showed no evidence of co-expression of GABAergic genes. These results suggest that expression of GABA signaling machinery in the cortically-projecting cholinergic system peaks during early development before settling at a non-zero level that is maintained through adulthood.

Oral health curricula in physician assistant programs: a survey of physician assistant program directors.

PURPOSE: a review of the medical literature indicates that physician assistants (PAs) are not educationally prepared for oral health issues. The purpose of this study was to evaluate the status of oral health curricula and the knowledge and skills taught within PA curricula. METHODS: a survey examining oral health curricula in PA education was distributed electronically to the directors of all 142 accredited PA programs in the United States. The survey focused on aspects of oral health that programs currently teach and aspects that merit future inclusion. The survey data were analyzed using SPSS version 17. RESULTS: eighty-three of the 142 PA program directors (58.4%) responded to the survey. Over 74% believed that dental disease prevention should be addressed in PA education, yet only 21% of programs actually did so. Most respondents (94.7%) also agreed that PAs should routinely assess and screen for early signs of dental disease and counsel patients on preventing dental problems. Currently, over half of PA programs teach examination of children's teeth for cavities (55.6%), dedicating on average 3.6 hours toward oral health education. Most respondents (more than 90%) expressed a desire to implement an oral health module in their programs. On average, program directors felt that 5.3 hours should be dedicated to oral health. CONCLUSION: many PA program directors believe that PA programs are responsible for educating students about oral health; however, most PA program directors report a lack of oral health education within their curricula.