Neurobiology and Neurochemistry of Cognition Flashcards
(23 cards)
Range of domains included within the idea of cognition?
Memory - short-term, semantic, working, long-term, procedural
Consciousness
Problem solving, calculation
Attention and concentration
Receptive and expressive language
Emotion
Perception
Judgement
Spatial awareness
Metacognition
Functions of the frontal lobe?
Frontal assoc. area
Motor cortex
Speech
Functions of the parietal lobe?
Somatosensory assoc. area
Somatosensory cortex
Speech
Taste
Reading
Functions of the temporal lobe?
Auditory assoc. area
Hearing
Smell
Functions of the occipital lobe?
Visual assoc. area
Vision
Function and location of Broca’s area?
Located in the frontal lobe and responsible for motor movements required to produce speech
Symptoms and signs of a deficit in Broca’s area?
Broca’s aphasia, AKA expressive apashia
Comprehension of speech is intact but patient partially loses the ability to produce language
Speech include important content words but excludes function works, that only have grammatical significance (AKA telegraphic speech)
Patients have effortful, non-fluent speech and often appear frustrated
Function and location of Wernicke’s area?
Located in the temporal lobe and is inv. in the comprehension or understanding of written and spoken language
Symptoms and signs of a deficit in Broca’s area?
Receptive, fluent aphasia - the patient is able to fluently connect words but they lack meaning
Patients do not appear frustrated with creating speech
Order of memory input?
Environmental input is first in sensory memory (shortest term memory); must pay attention to the info for it to be transferred into short-term memory
Short-term memory - can hold but not manipulate info for a time in the order of seconds; can store 7 +/- 2 items in here and can recall for up to 1 minute
With rehearsal, items can enter long-term memory; with retrieval, items in long-term memory can be brought back into short-term memory
Types of long-term memory?
Explicit (declarative) memory:
• Semantic memory - factual info with no personal experience, context, when info assoc. with it
• Episodic memory - experiences and specific events that occur during our lives
Implicit (procedural) memory - unconscious memory of skills and how to do things that we have practiced and repeated many times in our lives, e.g: tying a shoelace
What is dementia?
Progressive, irreversible, global decline in cognition that is significant enough to affect a patient’s daily functioning
Most common cause of dementia?
Alzheimer’s disease
NOTE - vascular dementia is the 2nd most common cause
Pathology of Alzheimer’s disease?
Formation of extracellular amyloid plaques (insoluble, misfolded protein), which are assoc. with inflammation
AND
Formation of intracellular neurofibrillary tangles
Which NT is important for memory?
Acetylcholine; their are various cholinergic projection pathways in the brain:
• Striatal interneurones for motor control
• Nucleus basalic of Meynert for attention / arousal
• Medial septal nucleus for learning and memory
• Brain stem nuclei
Mechanism of action of acetylcholinesterase inhibitors?
Boost cholinergic transmission but DO NOT treat the underlying pathological process
E.g: Dozepezil, Galantamine, Rivastigmine
What is memantine?
Licensed to treat moderate-severe Alzheimer’s disease
It is a low affinity voltage-dependent non-competitive antagonist of NMDA receptors; it may preferentially inhibit excessive NMDA receptor activation, which is assoc. with excitotoxicity, sparing normal function
It is also a weak antagonist at other amine receptors
What is vascular dementia?
AKA multi-infarct dementia
Typically caused by a series of strokes that have not been detected
Follows a gradual or STEP-WISE PROGRESSION and patients have a labile affect
What is Lewy body dementia?
Lewy bodies are clumps of α-synuclein and ubiquitin
Treatment for Lewy body dementia?
Cholinesterase inhibitors
DO NOT USE anti-psychotics
NOTE - avoid dopamine agonists, even if the patient develops Parkinsonism, as it worsens their mental state
What is frontotemporal dementia (FTD)?
Tends to occur at a younger age and inv. 3 syndromes, with most patients developing a mixture of these:
• Behavioural change
• Progressive non-fluent aphasia
• Semantic dementia
What is Wernicke’s encephalopathy?
Due to thiamine deficiency, 3 classical features occur, although only a few patients have all of them:
• Ophthalmoplegia
• Confusion
• Ataxia
Other signs and symptoms are: • Visual impairment • Hearing impairment • Reduced conscious level • Hypothermia • Lactic acidosis • Circulatory changes
It may occur alongside Korsakoff syndrome (AKA Wernicke-Korsakoff syndrome)
So remember to replace thiamine as prophylaxis
Causes of brain damage with alcohol misuse?
Wernicke’s encephalopathy
Korsakoff syndrome
Myelin sheath degradation
Neuroinflammation
Falls, leading to a subdural haematoma
