Structure and functions of cells of the nervous system Chapter 2 Localization of brain functions: System approach Gall Brocka, Wenicke Brain functions: The neuron approach Neuron is the basic computational unit: Input - synapse. Analysis integrate and fire. Output synapse. 12/11/06 Brain and basic functions: The reflexes Communication between neurons Arousal system wakes up the rest of the brain Integration of sensory modalities to a common concept ConvergenceConvergence Divergence How neurons decode the signal? The brain contains a network of ~ interconnected neurons. In every small volume of cortex, thousands of spikes are emitted each millisecond. What is the information contained in such spatio-temporal pattern of pulses? What is the code used by the neurons to transmit that information? How might other neurons decode the signal? Coding in the CNS Integration in the neuron Measuring the potential of a neuron Stimulation and recording of a neuron Action potential Relative concentration of ions inside and outside of the neurons Sodium-potassium pump Ion movements during action potential Membrane permeability during action potential Conductance of action potential Coding in the CNS Decremental conduction Saltatory conduction Synaptic variations Details of the synapse EM of a synapse Release of neurotransmitter Recycling of the membrane Ionotropic receptors Metabotropic receptors Ionic movement during postsynaptic potentials Reuptake of the neurotransmitter END