Dr. John H. Byrne
The University of Texas Health Science Center at Houston
McGovern Medical School
Department of Neurobiology and Anatomy
The research interests of this laboratory are the neuronal and molecular mechanisms underlying learning and memory. The marine mollusc Aplysia californica is being used as a model system to study mechanisms of implicit (nondeclarative) memory associated with simple forms of learning such as habituation, sensitization, classical or Pavlovian conditioning and operant conditioning.
A variety of molecular, biochemical, biophysical, electrophysiological, imaging, and computer simulation techniques are used to analyze the properties of the neural circuits and individual neurons. For example, with intracellular recording techniques we have found that simple forms of learning involve changes in synaptic transmission at existing synaptic connections. We have also determined that these changes are induced by the elevation of intracellular second messengers such as cAMP and DAG, which appear to act by modulating specific membrane channels and other cellular processes such as those associated with the machinery for transmitter release. We are now investigating how these processes are modulated both in the short-term of minutes by covalent modifications and in the long-term of days by growth factors and cAMP-induction of new gene transcription and protein synthesis. siRNA techniques are used to test the role of specific genes in memory and to knock down specific proteins to model neurological disorders. The empirical analyses are complemented with realistic mathematical modeling in order to determine whether the observed processes and their interactions are sufficient to explain the behavior of the system. We are also using these models to determine optimal training protocols to enhance normal memory and rescue memory deficits associated with neurological disorders.