Stefan M Brudzynski
Brock University, Canada
Scientific Tracks Abstracts: J Neurol Neurophysiol
Functions of the reticular activating system are fundamental for the maintenance of the state of wakefulness, consciousness, and vigilance. Evidence has cumulated suggesting that the activating system contains a group of several reticular systems that are specialized in many aspects of arousal. This talk will be focused on emotional arousal and will present two specialized emotional arousal systems that are working in parallel with the cognitive arousal system. In animals, emotional arousal is overtly signaled by an emission of state-specific vocalizations that allow for qualitative and quantitative studies of the emotional process. Laboratory rat represents the best studied mammalian species and rat ultrasonic vocalizations have been studied in depths over the last 20 years. They can be divided into two main categories of calls expressing negative or positive emotional arousal and state. The valence-specific vocalizations are labeled for simplicity according to their usual sound frequency as 22 kHz vocalizations expressing aversive (negative) states as anxiety, discomfort, and displeasure, while 50 kHz vocalizations expressing appetitive (positive) hedonic states as the reward or its anticipation, and play the joy. Based on the studies of brain control of ultrasonic vocalization emission, two arousal systems will be presented: (a) the ascending mesolimbic cholinergic system for aversive arousal and (b) the ascending mesolimbic dopaminergic system for appetitive arousal. These two ascending systems originate from tegmentum and their activity is based on two different neurotransmitters. The positive emotional state is induced by the release of dopamine while the negative emotional state is induced by the release of acetylcholine. These transmitters are released in vast subcortical limbic regions and are not targeted at the neocortex as the cognitive arousal system is. Functions of these two tegmental systems are extremely fast and seem to depend on the functionally antagonistic relationship between them that allows for the development of positive or negative emotional arousal but not both these states together. Results of these studies are relevant to neuropsychiatry and understanding of emotional states, their disturbances, and their relationship to cognitive functions of the brain.
Stefan M Brudzynski, PhD, D.Sc., is a neurophysiologist, neuroscientist, and biopsychologist, presently Professor of Psychology and Neuroscience at Brock University, St. Catharines, ON, Canada. He is a former Director of the Centre of Neuroscience and the recipient of the prestigious Lifetime Achievement Award from the International Behavioral Neuroscience Society for his contribution to the field of Behavioral Neuroscience. His main research interest is in the neural substrate of animal behavior, Neuropsychopharmacology, animal vocal communication, and particularly, central control of ultrasonic vocalization and communication in rodents. His current research is focused on the vocal expression of emotional states and brain systems for emotional arousal. He is editor of two fundamental handbooks on neural control of vocalization, Handbook of Mammalian Vocalization – An Integrative Neuroscience Approach (2010), and Handbook of Ultrasonic Vocalization – A Window into the Emotional Brain (2018).
E-mail: sbrudzynski@brocku.ca
