Pathways of emotion - from cortex to peripheral organsOctober 07, 2003Walking down a dark alley late at night is enough to give anyone the heebie-jeebies. Your heart starts racing, your palms get clammy and you get ready to run. Now researchers from Boston University have unravelled the neural pathways that transmit information about your surroundings to your organs, enabling them to respond appropriately. The research, to be published on Friday in BMC Neuroscience, has shown that neurons originating in high-order brain structures transmit signals about the environment relatively directly to low-order structures in the spinal cord. There is just one structure in the middle - the hypothalamus. The pathway then connects to autonomic nerves, which originate in the spinal cord, to regulate organ function. Helen Barbas, the research team leader, says: "The existence of these pathways has implications for several psychological conditions. For example, these pathways may be excessively active in anxiety, post-traumatic stress, and obsessive-compulsive disorder - conditions in which the emotional experience is extreme relative to the situation. Similarly, these pathways may be abnormally inactive in psychopathic individuals, who lack appropriate emotional responses." Other research in humans has implicated the prefrontal cortex in these conditions. When this area is damaged, patients lack emotional propriety and do not show the changes in heart rate and the skin responses that normally accompany emotional arousal. To map the neural pathways the researchers injected two different tracer molecules into the prefrontal cortex and the spinal cord. These molecules travel along the nerve axons, and the neurons can be seen as coloured structures through the microscope - the axons of the neurons originating in the cortex were red and the neurons that terminated in the spinal cord were blue. Both blue and red structures could be seen close together in the hypothalamus, specifically in those areas that are involved in the control of peripheral organs. This finding suggested that prefrontal cortex neurons could interact with neurons in the hypothalamus that send messages to the spinal cord. The team then used electron microscopy to look at nerve endings in the hypothalamus. They saw that neurons from one area of the prefrontal cortex terminated in large 'boutons' in the hypothalamus. The appearance of these boutons suggested that the prefrontal neurons have an excitatory effect on the neurons in the hypothalamus. Barbas said, "By combining two independent approaches to label multiple pathways simultaneously, we have demonstrated that the prefrontal cortex has relatively direct access to central autonomic structures. This evidence suggests that high-level prefrontal areas can rapidly influence autonomic areas in complex emotional situations". | |||||||||||||||||||||
|
Related Neurons Current Events and Neurons News Articles Study sheds light on causes of HIV dementia A new study led by researchers at Albert Einstein College of Medicine of Yeshiva University has clarified how two major variants of HIV differ in their ability to cause neurologic complications. Cold Spring Harbor Protocols features tissue culture methods for immune cells and neurons The complexity of vital organ systems makes them difficult to study in living organisms. Tissue culture methods for specific cell types allow researchers to break these systems down into component parts that can be readily manipulated and observed. Claudin 11 stops the leaks in neuronal myelin sheaths Devaux and Gow demonstrate how a tight junction protein called claudin 11 makes the neuronal myelin sheath a snug fit. Adult brain neurons can remodel connections Overturning a century of prevailing thought, scientists are finding that neurons in the adult brain can remodel their connections. New research helps explain genetics of Parkinson's disease A new study by Narendra et al. suggests that Parkin, the product of the Parkinson's disease-related gene Park2, prompts neuronal survival by clearing the cell of its damaged mitochondria. Memory mission explores new territory in neuroscience Astrophysicists peer into the far corners of deep space for dark matter, but for neuroscientists at the Queensland Brain Institute (QBI) exploring the unknown is much closer to home. A good ear: Rats identify specific sounds in noisy environments A study conducted on hundreds of rats could help us understand how the brain identifies specific sounds in a noisy environment. In the war against diseases, nerve cells need their armor In a new study, researchers at the Montreal Neurological Institute (MNI), McGill University, and the Université de Montréal have discovered an essential mechanism for the maintenance of the normal structure of myelin, the protective covering that insulates and supports nerve cells (neurons). Protein can nurture or devastate brain cells, depending on its 'friends,' researchers find Researchers at UT Southwestern Medical Center have uncovered new insights into the "Dr. Jekyll and Mr. Hyde" nature of a protein that stimulates stem-cell maturation in the brain but, paradoxically, can also lead to nerve-cell damage. Pivotal Emory study focuses on teens at risk for psychosis Emory University in Atlanta is playing a key role in the largest, most comprehensive study ever funded by the National Institute of Mental Health (NIMH) of adolescents and young adults at risk for developing a psychotic disorder. More Neurons Current Events and Neurons News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||