Mechanisms of Brain Arousal Flashcards
Disruptions in consciousness most often arise from lesions to what parts of the nervous system?
Brainstem
Midbrain
Hypothalamus
Synaptic convergence of sensory information onto what system alerts the brain that an event has happened?
Reticular activating system
PPT/LDT nuclei
What output pathway do the parabrachial nuclei utilize?
Ventral pathway
What NT is utilized in the period from coma => arousal/wakefulness?
EAA/Glutamate
ACh (RAS)
What output pathways are utlized by Pedunculopontine Tegmental(PPT)/Laterodorsal Tegmental(LDT) nuclei?
Dorsal and Ventral
What NT is utilized in the period from arousal to awareness? From what nucleus?
NE
Locus Coeruleus
The Locus Coeruleus receives input from what?
Paragigantocellularis N. (sensory)
Periaqueductal grey
Higher CNS centers (including cortex)
Activity of what nucleus can manifest on the EEG?
Locus Coeruleus
What are the functions of the noradrenergic system?
Startle and alerting response (manifested on EEG)
Sleep-wake
Behavioral vigilance
What is the primary output pathway for the serotonergic system?
Ventral (but utilizes both dorsal and ventral)
What NT is utilized in the period from awareness to alertness? From where?
Dopamine
Ventral Tegmental area
What is the state of cortical neurons in a persistent vegetative state?
Neurons are 10-30 millivolts hyperpolarized relative to their threshold
Where is neuronal loss manifested in a persistent vegetative state?
Rostral regions of pons/midbrain/thalamus
What state are thalamocortical neurons placed in during sleep?
Hyperpolarization (no excitation of cortex)
