University:
Western Sydney University
Course:
MEDI 2003 | Clinical Sciences 2
Academic year:

2024
Views:

317

Pages:

4
Author:

Mariam A. A.

Brain modulatory systems ● ● ● ● Modulate brain activity based on different features Reticular activating system is a network of neurons in the brainstem that controls the necessary functions to keep us alive Reticular formation are nuclei deep within the brainstem which influence the survival systems → motor control, cardiovascular control, pain modulation, sleep, habituation - There are between 9 - 100 nuclei in the diencephalon and brainstem - Underlying basic sensory systems throughout the body (inputs and outputs) Under control of the hypothalamus Brain modulatory systems ● Adrenergics - ‘Adrenaline rush’ and being really alert - Flight or fight response - Andergenic neurons are located in the locus coeruleus (near the pons) - Have an excitatory effect on different systems in the brain (help you escape, more alert) ● Dopaminergics - Based in the midbrain and partially into the pons - SN and VTA are regions of the brainstem that contain dopaminergic neurons - Substantia Nigra = motor/habits (not conscious, things that you don’t need to think about) - Ventral Tegmental Area = reward (feeling happy because of doing a behaviour ● Serotonergics - Role in positive mood/feelings and cognition - Serotonin release = positive mood = effect on cognition (able to concentrate more) - Sit in the midline of the brain stem in a region called the Raphe Nuclei ● Acetylcholinergic - Nucleus at the top of the pons (PN - Pedunculopontine nucleus) - Can see the orange arrows concentrated in the thalamus and hypothalamus - Attention and arousal - Memory/sustained attention and remembering things - REM sleep - Important for mental wellbeing - Psychosis if you don’t have enough REM sleep (thoughts and emotions are impaired) - Renews brain activity for the next day ● Histaminergic - Role in alertness, feeding and motivation - Histamines are inflammatory agents - Important for staying awake - Released from the tuberomammillary (in the hypothalamus) but affects the brain stem - Timing throughout the day (hunger at different times)