Colin Saldanha - US grants

DESCRIPTION (Provided by applicant): Steroid provision to neural pathways is achieved via endocrine pathways, but also paracrine and autocrine mechanisms within the brain itself. These modes of delivery underlie the considerable influence of steroids like estrogen on vertebrate brain and behavior, including that of songbirds. Using a novel antibody, we have discovered that estrogen can be provided to specific telencephalic neurons via synaptic innervation in the zebra finch (Taeniopygia guttata). This "synaptocrine" mechanism involves the transport of aromatase to synaptic terminals far from their source. This action combines the long-range characteristic of endocrine events with the targeted specificity of axonal innervation. Presynaptic aromatization could dramatically alter the steroidal milieu in the synaptic cleft, thus altering synaptic function. Recent findings that show the rapid modulation of aromatase activity by ionophores and estrogen receptor at post-synaptic densities strongly suggest that presynaptic aromatization is functional. In zebra finches and canaries (Serinus canarius), we will confirm the expression of synaptic aromatase using radioenzymatic assays and immuno-electron microscopy. Second, we will test the differential regulation of synaptosomal and microsomal aromatase, and the association of synaptic aromatization with singing behavior. Finally, we will establish the interaction of synaptic aromatase with estrogen- and androgen receptors using double-label confocal and electron microscopy. Presently, although synaptic aromatase has been documented in several species, including humans, nothing is known about its regulation and function. These studies will describe a mechanism that couples electrical and hormonal signaling, possibly revealing a fundamental and novel characteristic of neuroendocrine function.

A direct and tangible contribution of any scientific discovery or science-education lies in the creation of a springboard to success for the future generation of scientists. A resilient principle of the Society for Behavioral Neuroendocrinology (SBN) is our commitment to trainees. We see our trainees as the future of the field and thus; recruiting and welcoming them into, encouraging their participation in, rewarding their input to, and nurturing their continued inclusion among the SBN are all inherently critical aspects of the SBN mission. The SBN Education Committee will use NSF funds to stimulate, maintain, nurture, and reward the participation of post-doctoral fellows, graduate and undergraduate students at the 15th and 16th annual SBN meetings. In keeping with our commitment to recruit, retain, and reward trainees, funds will be used for: (1) Travel Awards. This allows trainees to present their work in a supportive environment and gain exposure to the breadth and depth of the field. (2) Career Development Workshops. Workshops are offered at each meeting to educate trainees on important career development topics and retain trainees in the sciences. (3) Mentor-Mentee Lunches. One-on-one discussions with senior mentors help trainees gain insight into the research enterprise, create new relationships, and find strong mentors. (4) Trainee Poster Competition. The competition an educational experience for all and it also provides an opportunity to encourage and reward success at each level, and, (5) the Young Investigator?s Symposium. Outstanding senior graduate students or post-docs are chosen to present talks in a dedicated symposium at the meeting. This format recognizes the accomplishments of such trainees, facilitates their movement into more advanced positions, and motivates younger scientists. The trainee events at the SBN meeting will play a key role in the attraction, retention, and reward of the brightest and best-trained transdisciplinary scientists.

With this award from the Major Research Instrumentation (MRI) and Chemistry Research Instrumentation and Facilities (CRIF) programs Professor Shouzhong Zou from American University and colleagues Colin Saldanha, Matthew Hartings and Douglas Fox have acquired an analytical transmission electron microscope (TEM). A TEM propels a beam of electrons at a thin sample. The electrons interact with the material to produce an image of the substance much as an optical microscope. However, the magnification is typically better than with optical microscopes. The microscope is used in a broad area of fields from materials research, to chemistry and biology to medicine. The microscopic knowledge gleamed from the TEM images can help understand the properties of the material and perhaps improve them. At American University the TEM is used to advance a number of research projects and it also impacts undergraduate research training and it is used in lecture and laboratory courses. It is also used in outreach activities to local institutions such as the University of the District of Columbia and Montgomery College to further enhance research and student training.

The proposal is aimed at enhancing research and education at all levels, especially in areas such as (a) revealing structure-catalytic activity relationships of catalysts for fuel cell reactions, carbon dioxide to organic fuel conversion and gas sensing, (b) understanding formation mechanisms and exploring structure-function properties of polymer-nanocomand organic ligand-stabilized noble metal nanoparticles, (c) developing advanced functional materials for water purification and disease detection, (d) understanding the expression and regulation of synaptic aromatase that synthesizes estrogens, (e) exploring structural modifications of retina associated with ambient light conditions and (f) revealing the reproductive system structure of decapod crustaceans.