Laboratory of Neuropsychoecoendochemistry
Postdocs, graduate students, undergraduates and research associates working in the Summers' lab
Recent work from the Summers' lab
Animal Models used by the Summers' lab
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The Laboratory of Neuropsychoecoendochemistry
Cliff H. Summers
Russ E. Carpenter
David H. Arendt
Justin P. Smith
Don't forget to visit the labs of our colleagues Ken Renner, Gina Forster and Pat Ronan

The name of our lab is a bit silly, our little joke, but it does say something about who we are and what we do:

Neurochemistry - the beginning and the end of the name, and often the thing we measure and interpret in our work. It also describes the tools of what we do: HPLC, microdialysis, chronoamperometry, immunohistochemistry

Neuropsycho - the first two parts of the word, and the real reason we are interested: how does the nervous system create behavior, and how are those behaviors modified by stress. We are paticularly interested in the influence of social behavior, learning and aggression on stress responses, and the reciprocal of stress on the behaviors.

eco - we are at heart a comparative lab, and very interested in the evolution of the mechanisms we study, and how they are influenced by the life history and ecology of the animal (see animal models). We think this is equally important for preclinical models of human stress and psychological disorders.

Neuroendo - we are also interested in the influence of endocrine systems, and neuroactive peptides and steriods on behavior and stress responsiveness.

Symposia Organized
Society for Integrative and Comparative Biology Symposium:

Stress - Is it More than a Disease?
A Comparative Look at Stress and Adaptation
Room: Churchill-Haines 178, 178A
Phone: (605) 677-6177
mailing address:
Cliff H. Summers
Department of Biology
University of South Dakota
Vermillion, SD 57069

Animal models

Anolis carolinensis (the green anole)

Anoles are uniquely suited to studying stress. Mechanisms of variability among individual neural and endocrine stress responses are the focus of our laboratory and the reason for choosing Anolis. There are differing reactions to stress among individuals of any species, but in A. carolinensis these differences are visible by means of a postorbital patch of skin which darkens. We are interested in elucidating the mechanisms by which experience modulates the responsiveness of neural and hormonal stress responses, and the eyspot gives us a visible marker for the timing of these events. These studies include measuring behaviorally stimulated changes in biogenic amines by HPLC using microdialysis and brain punch microdissection, using social aggression and dominance to stimulate neuroendocrine stress responses. This is meaningful because the eyespot provides predictive information on different responsiveness and social outcome. That is, the winner of an aggressive interactions during the establishment of dominance is foretold by the celerity of eyespot darkening: Winners/dominant males have darkening first. This reliable chromatic change makes Anolis carolinensis especially well suited to study differences in neuroendocrine responsiveness between individuals. Anoles are also interesting with respect to the relationships between stress, biological rhythms, and reproduction.

Eleutherodactylus coqui

This frog is a directly developing amphibian. As such, it is different from most other frogs which have a larval, or tadpole, stage, but similar to most other vertebrates. Because direct development has evolved recently in this taxon, coqui are a useful comparison for neural development with metamorphosing species.

Onchorhyncus mykiss (rainbow trout)

Like anoles, salmonid fishes are excellent models for testing the roles of neuroendocrine factors on social stress, and vice versa. Trout are used for the infamous Carpenter Escape Maze experiments.

Pimephales promelas

The fathead minnow is a useful model for studying the toxic effects of ammonia on central monoamines. Other animal models may employ some type of hepatic failure or shunt, which may confound the effects of ammonia on monoamines. Ammonia is a major concern for aquaculture and it appears that monomines can serve as a biomarker because they are depeleted in a concentration dependent manner. Further studies on a larger scale with other fish species will determine if this will be a useful marker.

Rat

This is the most well studied, and best understood neurobiological model. Much of our comparative work using other models is compared to the rat. Rats are used for the infamous Arendt Escape Maze experiments.