Neuro Revision

1. Neuro Revision Emily Hodgson

2. Limbic System

4. Cingulate gyrus Fornix Ant. Nucleus of thalamus Mamillary bodies Parahippocampal gryus Hippocampus Entorrhinal cortex R G Tunstall 2014

5. Limbic system • Convenient way of describing anatomically interconnected nuclei and cortical structures • Most nuclei control functions necessary for self and species preservation • Autonomic and endocrine function, particularly in response to emotional stimuli • Motivation and reinforcing behaviours • Memory • Olfactory connections – more important in other species

6. Hippocampus • Hippocampus is involved in memory (formation & recall) & is located in the inferior temporal lobe • Important role in turning short term into long term memory • Connecting emotions, sounds and smells to memories • Anterograde amnesia – no new memory formation. Able to recall long term memories • Also involved in navigation and spatial orientation • L. Memories involving language • R. Memories involving spatial/visuo-spatial tasks

7. Anterograde Amnesia

8. Retrograde amnesia • Loss of memory/ unable to recall events occurring before the accident/event etc • Usually damage to brain other than the hippocampus

9. Different types of memory • Short term - <1hr • Long term • Declarative/explicit – recall of fact/event/knowledge (takes effort) • Implicit/procedural – learned skills (writing, motor, language)

10. Korsakoff’s psychosis • Part of Wernicke-Korsakoff syndrome (Wernicke encephalopathy normally first) • Mamillary and anterior thalamic damage due to thiamine (B1) deficiency • Memory loss • Difficulty acquiring new information or skills • Change in personality • Confabulation – invents events to fill the gaps in memory

11. Cingulate gyrus • Regulate emotion and pain • Directly drive body’s conscious response to unpleasant experiences • Fear and prediction (and avoidance) of negative consequences – important feature of memory • Autonomic area – cardiorespiratory and digestion • Bladder control • Visual searching

12. Cingulate gyrus • Anterior lesions: • Autonomic dysregulation • Emotional disturbances • Posterior lesions: • Memory/cognitive dysfuction

13. Amygdala • Multiple inputs/activators: • Visual & Auditory • Sensory from body • Solitary tract • Olfactory & Limbic system • Hypothalamus

14. Multiple Outputs: • Hypothalamus • Hippocampus • Multiple areas of cortex

15. Controls multiple emotions, responses and systems • Brings about reactions of: • Fear • Anger • Behavioural emotions • Sweating, flight, fright, confrontation, mating • Impulsivity • Sexual behaviour & emotions

16. Stimulation can: • Increase HR & BP • Reduce saliva • Increase GI motility • Cause irritability • Startle easily • Increase muscle tension • Cause pupil dilation

17. Septal nuclei – pleasure • Nucleus accumbens – • Dopamine activated reward centre • Intense sense of well being • Amphetamine and cocaine activate

18. Hypothalamus • Primary output for limbic system • Sexual function, endocrine function, behaviour and autonomic control • Inputs from most of the body (olfaction, viscera, retina) • Internal sensors for temp, osmolality, glucose and sodium conc, hormones

19. Eyes (Visual Fields)