Neurophysiological Research Supporting the Investigation of Adaptive Network Architectures.

Effects of neutral modulators were studied in single cortical neurons that undergo adaptations that support learned behavior. Ionic conductances were measured directly, in vivo, using single electrode voltage clamp techniques. After extracellular application of acetylcholine and intracellular application of cyclic GMP dependent protein kinase decreases in a fast outward membrane current were found. These modulatory agents are thought to regulate simple forms of learning in cortical cells. Other experiments studied effects of cyclic AMP and cyclic GMP on neuronal properties and identified regions of the hypothalamus, when stimulated, increased rates of acquisition of simple learned behavior. Single units of the motor cortex and their adaptive properties were studied before and after rapid conditioning and extinction of conditioned motor responses. The results provide insights into the design and operation of elements that serve adaptive neural networks within the brain needed for some forms of learning.