Flashcards in 7.6 Neuromodulatory Transmitter Systems Deck (21)
What is a neuromodulator?
Substance of transmitters which modulate the efficacy of synaptic transmission but cannot produce firing alone
Mainly act via metabotropic receptors
What are the catecholamines?
Dopamine and noradrenaline
What is the biosynthesis of catceholamines?
Tyrosine (tyrosine decarboxylase) - L-DOPA (amino acid decarboxylase) - Dopamine (dopamine B hydroxylase) - Noradrenaline (phenylethanolamine-N-methyltransferase) Adrenaline
Which molecule in the biosynthesis of catecholamines can cross the BBB?
What breaks down catecholamines?
MAO and COMT
Where are the dopamine nuclei found and where do thy project to? and which diseases are implicated in each?
Substantia nigra - project to the striatum of the basal ganglia and facilitate the initiation of movement - PARKINSONS
Ventral tegmental area: innervate the forebrain which includes the pre-frontal cx and parts of the limbic system - SCHIZOPHRENIA
Where does the noradrenergic system start and project to?
Starts in the locus coeruleus and the reticular formation and projects to many parts of the cortex including the cerebellum, thalamus, neocortx, hypothalamus, amygdala and hippocampus
What is the transduction and function of the NA system?
Transduction is via adrenergic receptors
Function: attention and vigilance and phasic changes in levels of attention
What drug acts on the NA system?
What are the ionotropic and metabotropic receptors for serotonin?
Metabo: 5-HT 1,2 and 4-7
What does serotonin need to be made?
Where are serotonin neurons located and where do they project to
Locates in the raphe nucleus (caudate and rostral) with very dense and profuse innervation
What is the function of the serotonin system?
Aggression and impulsivity
Anxiety and depression
Descending pain control
What drugs exert their effects through the 5-HT system?
What is the iono and metabotropic receptors for ACh?
Iono: pentamer of 2a, Ib, Igamma, 1 delta subunis
Where are ACh neurons found and where do they project to?
Basal forebrain: nucleus basils and septal nuclei
- hippocampus and all neocortex
- thalamus and part of forebrain
What is the function of the cholinergic system?
Learning and memory - alzheimers
Arousal and sleep/wake cycle
What drug acts on the cholinergic pathway?
What is the receptor for orexin/hypocretin?
Metabotropic - OXIR1 and 2 which is coupled via Gq to IP3 pathway
How is orexin/hypocretin broken down?
internalised as receptor/transmitter