Nancy L. Wayne - US grants

DESCRIPTION: (adapted from Applicant's Abstract) The long-term objective is to understand neural control of hormone secretion and its impact on reproductive physiology and behavior using the marine mollusk Aplysia californica as an animal model. Because of their simple nervous system and large neurons, Aplysia have been widely used for biophysical, cellular and molecular investigations of the neuroendocrine cells (called bag cells) that control ovulation and egg-laying behavior. However, there has been little work on the processes that regulate hormone secretion from these cells. The proposed work will use bag cells and their secretion of egg-laying hormone (ELH) to identify cellular mechanisms that regulate dynamic changes in hormone secretion. The specific aims are to determine: whether patterns of bag-cell electrical afterdischarge and ELH secretion are similar between in vivo and in vitro preparations; and to determine the role of the diacylglycerol (DAG), calcium and cAMP in regulating ELH secretion.

It has long been suggested that stress, especially chronic stress, can alter the way in which our bodies normally function. Stress (both physiological and psychological) alters various immune functions, which could potentially be an important factor in linking chronic stress to a variety of physiological abnormalities. More recently, scientists have become interested in the interactions between stress, the immune system, and the brain. There is a growing body of evidence that stress can stimulate chemical secretions from immune cells (these chemicals are called cytokines), and that these cytokines can in turn alter specific brain functions. This POWRE award will investigate the relationship among immune, neuroendocrine and brain function. This project is particularly suited for a POWRE award because it will allow exploratory work to determine the feasibility of a new line of inquiry for Dr. Wayne. The purpose of the proposed work is to investigate the effects of cytokines on the function of a subset of cells from the brain - neuroendocrine cells that are responsible for secreting a hormone that controls reproductive behavior. An animal model with a simple nervous system, the marine mollusk Aplysia, will be used. The rationale for using Aplysia in the proposed studies is that, unlike with most higher organisms, their neuroendocrine cells can be easily identified in living tissue. That means that we are able to monitor the physiological response of these brain cells to cytokines; we can measure changes in both their electrical and secretory activities in response to chemicals that are secreted by stress-activated immune cells. Furthermore, marine invertebrates have a primitive immune system that is functionally analogous to that of mammals, including cytokines and stress-related hormones that appear to be structurally similar to their mammalian counterparts. The objective of this proposal is to develop the reproductive neuroendocrine cells of Aplysia as a model system to understand the effects of cytokines, and in particular interleukins and neurotrophins, on membrane excitability and downstream neuroendocrine cell functions by addressing the following specific aims: 1) determine the effects of interleukins and neurotrophins on neuroendocrine-membrane excitability and hormone secretion, and 2) determine the effects of interleukins and neurotrophins on hormone mRNA levels and hormone biosynthesis in Aplysia neuroendocrine cells.

This three-day conference will provide a forum for in-depth dialogue on innovative research in the area of Neural Control of Behavior. The first two days will be devoted to a symposium that will be open to the scientific community. There will be four sessions: Neurosecretion Over Different Time Domains; Genetic Dissection of Behavior; Local Protein Synthesis During Neuronal Plasticity and Regeneration; and Learning and Memory: New Directions. The speakers will discuss a wide spectrum of species (use of invertebrates to mammals) and experimental approaches (from molecular and cellular to behavioral levels of analyses). The third day of the meeting will be devoted to a workshop among only the speakers, where they will explore ways in which information discussed during the symposium can be used to take their respective research areas in new directions. This conference aims to: Bring together researchers who are asking similar questions, but are using different species and different experimental approaches; Promote the use of simple systems for addressing complex biological problems; Promote interaction between junior scientists - women in particular - and established investigators and leaders in the field. The speakers use modern, cutting-edge technologies for addressing problems in the area of Neural Control of Behavior. By bringing together these researchers, and giving them a forum for discussing their work, the message can be effectively spread that these modern techniques are being used with great success in a wide variety of animal systems. This conference will provide an important interdisciplinary communications-mechanism for advancements in the neuroscience community.

[unreadable] DESCRIPTION (provided by applicant): The broad objective of the conference is to provide a forum for in-depth dialogue in the area of Neural Control of Behavior, with the goal of coming up with ways that investigators can take their research in new directions. The specific aims to meet this goal are the following: Bring together researchers who are asking similar questions in the area of Neural Control of Behavior, but are using different model systems (from worm to fly, to bird, to mammal) and different experimental approaches (from molecular genetics, to cellular and systems physiology, to behavior); Promote the use of simple model systems for addressing complex biological problems in the field of Neural Control of Behavior; Promote interaction between junior scientists - women in particular- and established investigators and leaders in the field; Provide a high-quality educational forum, in an intimate setting, that is conducive for in-depth discussion and learning. [unreadable] The meeting will take place over the course of 3 days. The conference begins with a keynote lecture by Dr. Thomas Insel, Director of the NIMH. The first two days will be devoted to a symposium that will be open to the general scientific community (est. 150 registrants). There will be a total of four sessions with 5 speakers per session: (1) Neurobiological Basis of Social Behavior; (2) Fear and Anxiety; (3) Sleeping and Dreaming; (4) The Aging Brain. The speakers represent a balance of model system (use of invertebrate, lower vertebrate, and mammal) and experimental approach (use of molecular, cellular, systems, and behavioral levels of analyses), career level and gender. The third day of the meeting will be devoted to an intimate workshop of the speakers and conference participants (est. 30 participants). The aim of the workshop is to discuss strengths of the different model systems and experimental approaches discussed during the symposium, and come up with ways that we can use that information to take our respective research areas in new directions. The speakers at this meeting use modern, cutting-edge technologies for addressing problems in the area of Neural Control of Behavior. By bringing together these researchers, and giving them a forum for discussing their experimental approaches, the message can be effectively spread that these modern techniques can (and are) being used with great success in a wide variety of model systems. This will provide an important interdisciplinary communications-mechanism for advancements in the basic-science biomedical community. [unreadable] [unreadable]

This Conference on the Neural Control of Behavior will be held at UCLA. It addresses technical innovations that are now being applied to unconventional model organisms. Participants in this program possess expertise in behavioral neuroscience, neuroendocrinology, endocrinology, animal behavior, and developmental biology. The conference will engage both senior and junior ranked scientists and students in discussions regarding ways that investigators can take their research in new directions. Travel funds will allow participants to attend the meeting.
The impact of this will extend to numerous fields of study, as mentioned above. In addition, the meeting will foster scientific education by training graduate and undergraduate students to participate in comparative biological research armed with a clear understanding of novel sophisticated technology placed in the framework of behavioral questions. Assessment tools will be utilized to develop strategies for organizing next years meeting..

PI: Nancy Lynne Wayne
NSF SGER proposal #031407
Title: "Role of CREB in regulating neuropeptide synthesis"

Neuropeptides are responsible for controlling different aspects of physiology and behavior including body growth, eating, drinking, sex, etc. The broad goal of this proposal is to understand cellular mechanisms controlling synthesis of a neuropeptide hormone using neurons that control reproduction in the mollusk Aplysia. Earlier studies from this laboratory showed that electrical excitation of the reproductive neuroendocrine bag-cell neurons (BCNs) led to large amounts of secretion of the neuropeptide egg laying hormone (ELH). The releasable amount of ELH was replenished by upregulating ELH synthesis at the expense of most other proteins in the BCNs. It was revealed that electrical excitation of the BCNs stimulated a novel protein-synthetic pathway involving a special code on ELH mRNA called an internal ribosomal entry site (IRES). This is similar to how viruses control protein synthesis in cells following infection, and was not thought to play a physiological role in cellular systems. The aim of the proposed studies is to understand how stimulation of the BCNs activates the IRES on ELH mRNA. Based on earlier work, it is hypothesized that the cyclic AMP second messenger pathway (via cyclic AMP response-element binding protein, or CREB) is playing an important role in mediating the effects of electrical excitation on IRES activation, leading to upregulation of ELH synthesis. To test this hypothesis, expression of CREB will be obstructed by RNA inhibition, and the effects on electrical excitation of ELH synthesis and IRES activation will be documented. This experiment uses a combination of molecular, biochemical, electrophysiological, and optical imaging techniques. It is expected that inhibition of CREB will prevent electrical activation of the IRES and subsequent upregulation of ELH synthesis. This work is at the forefront of a completely new way of thinking about the way that cellular systems can regulate synthesis of proteins

Neurohormones are responsible for controlling different aspects of physiology and behavior including body growth, eating, drinking, and sex and reproduction. The broad goal of this project is to understand cellular mechanisms controlling synthesis of a neuropeptide hormone using neurons that control reproduction in the mollusk Aplysia. Earlier studies from the PI's laboratory showed that electrical excitation of the reproductive neuroendocrine bag-cell neurons (BCNs) led to large amounts of secretion of the neuropeptide egg-laying hormone (ELH). It was revealed that electrical excitation upregulates ELH synthesis to replenish releasable stores of hormone by both sodium- and calcium-dependent pathways that are independent from both ELH secretion and action potential firing. Furthermore, a novel protein-synthetic pathway involving a special code on ELH mRNA called an internal ribosomal entry site (IRES) plays an important role in mediating the effects of electrical excitation on upregulating specifically ELH synthesis, at the expense of non-essential proteins in the cell. This is similar to how viruses control protein synthesis in cells following infection, and was not thought to play a physiological role in cellular systems. The aim of this project is to understand the mechanistic links between membrane electrical excitation, sodium/calcium ion fluxes into the bag cell neurons, IRES activation on ELH mRNA, and ELH synthesis. Experiments will utilize electrophysiological monitoring of membrane electrical excitability and optical imaging of intracellular calcium concentrations in response to treatments that alter sodium/calcium flux, biochemical measurement of ELH synthesis, and a combination of molecular biological tools and optical imaging to monitor IRES activation in living bag cell neurons in the intact Aplysia nervous tissue. The outcome from the proposed experiments will lead to entirely novel conclusions regarding the control of specific protein synthesis in cells. This project provides excellent training opportunities for graduate and undergraduate students embarking on cutting-edge studies using an integrative experimental approach

This three-day conference will provide a forum for in-depth dialogue on
innovative research in the area of Neural Control of Behavior. The first
two days will be devoted to a symposium that will be open to the scientific
community. There will be four sessions: (1) Neurobiological Basis of Social
Behavior; (2) Fear and Anxiety; (3) Sleeping and Dreaming; (4) The Aging
Brain. The speakers represent a balance of species used (invertebrates to
mammals), experimental approaches used (from molecular and cellular to
behavioral levels of analyses), gender, and career level. The third day of
the meeting will be devoted to a workshop of speakers and invited conference
participants, where they will explore ways in which information discussed
during the symposium can be used to take their respective research areas in
new directions. This conference aims to: Bring together researchers who are
asking similar questions, but are using different species and different
experimental approaches; Promote the use of simple systems for addressing
complex biological problems; Promote interaction between junior scientists -
women in particular - and established investigators and leaders in the
field; Provide a high-quality educational forum, in an intimate setting,
that is conducive for in-depth discussion and learning between trainees and
more senior researchers. A Meet-the-Speaker luncheon is aimed specifically
at trainees, giving them the unique opportunity to interact with
internationally recognized experts in an intimate setting. A Poster Session
also gives trainees and more senior researchers the opportunity to highlight
and discuss their own work. The speakers use modern, cutting-edge
technologies for addressing problems in the area of Neural Control of
Behavior. By bringing together these researchers, and giving them a forum
for discussing their work, the message can be effectively spread that these
modern techniques are being used with great success in a wide variety of
animal systems. This conference will provide an important interdisciplinary
communications-mechanism for advancements in the neuroscience community.