David Potter - US grants

This proposal has arisen from a 9-year old study of transmitter choice in cultured sympathetic principal neurons of the rat. When developing in certin culture conditions, these neurons can be shifted from adrenergic to cholinergic status (a new form of neuronal plasticity). To study this transition in developing neurons, we devised a microculture method which permits the electrophysiologically-characterized transmitter status of a single neuron to be correlated directly with the fine structure of its endings or its immunoreactivity. With this method we found that during the transition, the neurons display adrenergic:cholinergic dual function, and that the transition can be followed directly by recording repeatedly from the same neuron over periods up to 45d. This method also revealed that some neurons secreted another transmitter, probably adenosine, with one of the amines. Neurons dissociated from adult ganglia also sometimes display adrenergic:cholinergic dual function. Parallel studies of primary sensory neurons and myenteric neurons are now well underway. Recently, several laboratories have reported tha sympathetic, sensory, and myenteric neurons of adult rats disply immunoreactivity for many active peptides (5 in sympathetic neurons alone); there is evidence for secretion of several, nd for amine:peptide dual function. This indicates that transmitter choice and its control are considerably more complex in these types of neurons than previously supposed. Since the culture methods mentioned above permits a direct study of synaptic functions, including multiple-transmitter status, which is often difficult in vivo, we have begun investigation of peptidergic functions in our cultures. We have preliminary evidence for Substance P-like and Avian Pancreatic Polypeptide-like immunoreactivity. In this proposal we request support for a systematic investigation of peptidergic functions in our cultured peripheral neurons. Our specific aims are: i) With conventional immunocytochemical methods to screen four types of cultured neurons (sympathetic, sensory, myenteric and parasympathetic) for peptides reported in vivo. ii) To co-culture the neurons with target cells sensitive to the peptides, in the novel microcultures, and to correlate peptidergic functon, fine structure and immunoreactivity in single neurons. iii) To investigate the control of expression of peptidergic functions as we have previously done with adrenergic:cholinergic functions. The long-term objective is to enlarge understanding of transmitter choice, a fundamental aspect of neuronal cell biology.

Recent work on sympathetic neurons indicates that their transmitter status is more complicated than the current textbook views; there is evidence for new transmitters, (e.g. purines, peptides), multiple-transmitter status, plasticity and graded expression. The long term objective is to investigate these complexities with a "microculture" method devised in this laboratory that permits an unusually direct study of each of these new complexities in single neurons co-cultured with appropriate target cells. Neurons dissociated from perinatal or adult ganglia of rats will be grown, one or a few at a time, on tiny islands of target cells (e.g. other neurons, cardiac or smooth myocytes); transmitter status is determined by stimulating the neuron and recording electrically from the neuron and its target cells, with use of appropriate drugs. The fine structure or immunocytochemistry can be then correlated directly with the function of this neuron. Specific aims: 1. With regard to the adrenergic-to-cholinergic transition, to investigate i) Retention of certain adrenergic properties. ii) Can the transition be reversed? iii) Are adult neurons back-labelled from a particular target tissue homogeneous in transmitter status and its transition(s)? iv) In a multiple-function neuron, is a single varicosity multiple in function? A single vesicle? 2. With regard to purinergic function(s) to invetigate i) The pharmacology of purinergic function; are there separate P1 and P2 -receptors? Uptake mechanism? ii) Investigate the storage mechanism(s) for secreted purine(s). Health relatedness. These new complexities of transmitter status are of general interest in neurobiology. A proper understanding of neuronal control of internal organs depends on an understanding of these complexities.

The long term goal of this project is to increase the numbers of active neuroscientist who are from minority groups currently underrepresented in the field. The following Specific Aims are to be accomplished: 1. To bring underrepresented minority neuroscientist and/or neuroscientists aspirants to an Annual Meeting of the Society For Neuroscience where they will be: a. Exposed to recent developments in neuroscience in particular; b. Socialized to mainstream science in general and neuroscience in particular; c. Presented with a broad array of research and career opportunities in neuroscience. 2. To provide formal instruction in professional development to a select group of underrepresented young minority neuroscientist and/or neuroscience aspirants.

[unreadable] DESCRIPTION (provided by applicant): [unreadable] Selected Native communities and schools have established a partnership with Harvard University (under the auspices of the Harvard University Native American Program and Harvard Medical School [HMS]) to create a pilot summer program, "Phase I: Opening the Pipeline for Native High Schools." The Program's major goals are to improve the opportunity for, (1) Native American high school students to engage in science education and pursue careers in the biomedical sciences at leading institutions and, (2) to provide training to their teachers in the content and pedagogical methods of biomedical sciences. The students and teachers will be housed in Cambridge and attend classes at HMS. The program, building upon earlier smaller programs, will consist of two three-week sessions, each accommodating 20 students and 4 teachers. The Native communities will determine the selection of the students, teachers and biomedical science topics. To address the first major goal, the program aims to familiarize students with life at a large urban university (demystify higher education); enhance the students' knowledge of biomedical science through lectures, similar to those they will encounter in college, and through Case-Based Learning (CBL), which demonstrates the relevance of science to real life problems; help students improve their learning skills; challenge students to think explicitly about their future plans, and to raise their sights; and encourage students' later attendance at Harvard Summer School. In addition, students will undertake individual projects, which they will present in a PowerPoint talk in a Final-Day Symposium, and will also devise and present a play. To address the second major goal the program aims to enhance teachers' knowledge base in biomedical science; train teachers in designing and implementing CBL in their classrooms; help teachers analyze their pedagogical methods and incorporate new ones. In addition, a Tribal Professional will attend for one week to lead discussions about the community impact of the specified health-related topic. [unreadable] [unreadable]

[unreadable] DESCRIPTION (provided by applicant): This Phase II application is a continuation of a 3-year Phase I SEPA entitled "Opening the Pipeline for Native High Schools". The major Broad Long-term Goal, from the outset, has been to increase the probability that students at high schools in four Native communities will pursue undergraduate and graduate training in biomedical sciences and medicine at leading institutions. Teams of ten students and two teacher-chaperones, picked by each of the four participating Native communities, attend the Native American High School Summer Program (NAHSSP) at Harvard for three summer weeks; two communities attend in June, two in July. The academic subject has been abuse of alcohol and cocaine or methamphetamine. Lectures, conference sections on basic neuroscience and the lecture material, and stepwise consideration of a multi-part case of multiple substance abuse discussed in small-group tutorials, were the major curricular elements. During the third week, the students produced a project for presentation in their home communities. The health relatedness of the project includes raising the educational expectations of the students, teachers, parents and communities; raising the understanding of students and teachers about the basic science and psychology of substance abuse and its consequences (an important issue in each community); and encouraging the students and teachers to be active in facilitating community change [substance abuse is not "normal"]. In the 03 summer (2007), a new, highly successful case, that described a teenage substance-dependent Fort Peck resident, was written collaboratively by teams from Fort Peck and Harvard Medical School. The Specific Aims of this Application are: Dissemination activities including: i) Aiding all four communities (the Fort Peck Reservation; the Hopi Reservation; a Native Hawaiian group and two Wampanoag communities on Cape Cod) to write medical cases that reflect their local contexts; ii) Encouraging the students to present these projects to various target groups at home; iii) Developing a website, at Harvard Medical School, that will post the curricular materials, describe the best practices of NAHSSP and host an interactive site for sharing information; iv) Hosting a symposium, at Harvard, of representatives of other Native communities and educational institutions to share needs and experiences. A goal of the dissemination activities is the formation of new community/university partnerships that will take useful elements of NAHSSP to build their own programs. Another aim is to develop more rigorous evaluation procedures appropriate for use in Native communities. [unreadable] [unreadable] This SEPA Phase II project ( 2 R25 RR020406-04) will improve the understanding of teams of Native high school students and high school teachers, in four Native communities, about the neuroscience and clinical psychology of drug abuse and alcoholism. These understandings will make the teams more interested and more effective in helping to reduce this serious problem. At the same time, the expectations of the students, their teachers, parents and communities with respect to undergraduate and graduate professional trainings will rise. [unreadable] [unreadable] [unreadable]