Consciousness and memory 💘 Flashcards
Reticular activating system nuclei
Locus coeruleus
Raphe nuclei
Ventral regimental area
Chokinergic nuclei
Locus coerulus
Located in pons
Hypoactivity associated with depression destruction obliterates rem sleep
Neurotransmitter used is noradrenaline
Raphe nuclei
Located in midline of midbrain pons medulla
Active during waking state
Neurotransmitter is serotonin
Ventral tegmental area
I’m ventral region of midbrain Modulates frontal activity Reinforces pleasurable sensations Implicates in drug addiction Neurotransmitter is dopamine
Cholinergic nuclei
One set in basal forebrain other in dorsolateral pontine Active during arousal Contribute to synaptic plasticity Involved in learning and memory Damage causes dementia Neurotransmitter is ach
Other areas involved in consciousness and sleep
Anterior hypothalamus damage associated with insomnia neurotransmitter GABA
Posterior hypothalamus damage associated with too light sleep neurotransmitter histamine
When awake
ACH system active sensory thalamus facilitated reticular nucleus inhibited, cortical neurons active EEG desynchronous
ALL OPPOSITE WHEN ASLEEP
Two main types of sleep
Synchronized/ non rem EEG waves slow and synchronized
Low frequency
Desynchronised rem high frequency abolition of muscle tone and associated with dreams
Memory stores
Sensory stores (kept in visual neurones)
Short term store
Long term store
Dependencies
Context dependency The environmental conditions in which you learn the info, state dependency which is the feeling the same as when you learn it and
mood dependency eg is recalling sad information when you’re feeling sad
Amnesia
Long term memory impairment
Childhood memory fine
Memories become less dependent on hippocampus and more reliant on neocortex for consolidation
Non declarative memory (motor) and semantic information (factual knowledge) is preserved
Semantic dementia
Damaged in the cortical store
the progressive loss of conceptual knowledge and can’t recognize objects things that remain intact include memory for recent events phonology visual spatial skills nonverbal reasoning
need damage to both sides of hippocampus for amnesia
there’s a reverse temporal gradient which is impaired repository of distant events as well as facts
Ltm stores
Hippocampus does episodic memory unique episodes involving places people as an objects and is damaged in amnesia
Anterior temporal lobe contains semantic memory similarities between experiences to form concepts and it’s damaged in SD
Over what time span are short term memories stored
A few seconds but can be longer with rehearsal
What type of encoding provides most distinctive cues for recall of info
Semantic memory
Two types of neurotransmitters
Small molecule: clear core vesicles for fast signalling
Lathe neuropeptides: dense vesicles and slower signalling. Modify ongoing synaptic function
Glutamate
Formed from glutamine via glutaminase
Has three Ionotrpic receptors which are AMPA, NMDA, kainate. Entry of na in AMPA receptor depolarize cell causing magnesium Ion to be ejected opening NMDA receptor channel Calcium flows in and activates secondary messages
GABA
Glutamate converted into gaba bia glutamate decarboxylase
GABA transaminase converts it back into glutamate
Gaba has five subunits
Epilepsy
Uncontrolled excitation in the brain imbalance between exciting and inhibitory neurotransmitters
treatments include diazepam which enhances gabas inhibition.
Sodium valproate which increases GABA content in brain
Glycine
Acts mainly in brainstem and Ispinal cord
associated with general motor and somatosensory systems and there’s a major spinal cord inhibitory neurotransmitter
it’s ionotropic receptor which is linked to chloride channels
defects can be implicated in hyperplexia
serine is converted into glycine via SHMT and glycine can be converted into carbon dioxide and ammonia
Tetanus blocks glycine so overactivation
Renshaw cell
Controls activity of motor neuron and requires glycine
Tyrosine and other biogenic amines
Tyrosine>dopa>dopamine> noradrenaline> adrenaline
These are catecholamines all contain catechol group all contain tyrosine hydroxylase
Serotonin
Synthesized from tryptophan
Aka 5ht
Reuptake into presynaptic mediated by SERT
Seven types of receptors mostly metabotropic
Neuro modulators
Modify post or pre synaptic responses
Dopamine
Dopamine receptors classified as d1 like and are positively coupled to adenylate Cyclase via gs (synthesis) protein (d1&5)
Or classified as d2 like and negatively coupled to ac via gi (inhibition) protein (d234)
Dopamine removed by MAO or COMT
