Long-Term Activity-Dependent Plasticity of Action Potential Propagation Delay and Amplitude in Cortical Networks

Background: The precise temporal control of neuronal action potentials is essential for regulating many brain functions. From the viewpoint of a neuron, the specific timings of afferent input from the action potentials of its synaptic partners determines whether or not and when that neuron will fire its own action potential. Tuning such input would provide a powerful mechanism to adjust neuron function and in turn, that of the brain. However, axonal plasticity of action potential timing is counter to conventional notions of stable propagation and to the dominant theories of activity-dependent plasticity focusing on synaptic efficacies. Methodology/Principal Findings: Here we show the occurrence of activity-dependent plasticity of action potentia

The autonomic nervous system

The autonomic nervous system innervates the visceral organs, the glands and the blood vessels. It regulates the internal environment, and it is largely responsible for maintaining normal bodily functions such as respiration, blood pressure and micturition. The peripheral autonomic nervous system consists of two parts, a thoracolumbar or sympathetic and a craniosacral or parasympathetic division, which usually have antagonistic effects (Sect. 12.2). The sympathetic system is organized to mobilize the body for activities, especially in stressful situations (Cannon’s fight or flight), whereas the parasympathetic system in particular stimulates the peristaltic and secretory activities of the gastrointestinal tract (also known as rest and digest response). The peripheral part of the autonomic nervous system includes neurons in the viscera and peripheral ganglia, which are innervated by the lateral horn of the spinal cord and certain brain stem nuclei. Neuronal plexuses in the gastrointestinal tract form the enteric nervous system, which is often viewed as the third component of the autonomic nervous system. Tonically active bulbar centres control vital functions such as blood pressure and respiration. The autonomic centres in the brain stem and spinal cord are reciprocally connected with the central autonomic network (Sect. 12.3), which includes the hypothalamus and several other forebrain (in particular the extended amygdala and the insula) and brain stem structures such as the periaqueductal grey and the parabrachial nucleus. This network is essential for the integration of autonomic, endocrine and somatomotor functions. The peripheral and central autonomic pathways may be affected by many diseases, which cause derangement of autonomic functions as exemplified in several Clinical Cases on disorders of the neural control of blood pressure, breathing and micturition. The English terms of the Terminologia Neuroanatomica are used throughout