2: Cellular Physiology Of The Brain Flashcards
What are the most abundant glial cells?
Astrocytes
What are the functions of astrocytes
Structural support
Form part of BBB
Removal of neurotransmitters
Providers nutrition for neurones
What are microglia?
Essentially macrophages of the brain that remove foreign material by phagocytosis
What is the major excitatory neurotransmitter and what receptors does it act on?
Glutamate
Acts on AMPA/ NMDA
What are the major inhibitory amino acids?
GABA and glycine
GABA is the main inhibitory neurotransmitter in the brain, glycine is the main inhibitory neurotransmitter in the spinal cord
What neurotransmitter is enhanced by benzodiazepines and barbiturates?
GABA
Hence they are used in anxiety, insomnia and epilepsy
What is the major excitatory neurotransmitter and what receptors does it act upon?
ACh
On nicotinic and muscarinic receptors
Degeneration of cholinergic neurones is associated with which condition?
Alzheimer’s disease
Hence why AChE inhibitors are used
What behaviours are the mesolimbical and mesocortical pathways involved in, and via which neurotransmitter?
Dopamine
Involved in reward, mood and arousal
What condition if associated with an excess of dopamine?
Schizophrenia
Hence antipsychotic inhibit dopamine receptors
What is the nigrostriatal pathway involved in, and via which neurotransmitter?
Motor control
Via dopamine
What condition is associated with a loss of dopaminergic neurones in the NG pathway?
Parkinson’s
What receptors does NA act on?
GPCRs
What condition is associated with a NA deficiency?
Depression
Why is L-DOPA for Parkinson’s also prescribed alongside carbidopa, and what is the action of this?
Carbidopa is a AADC (decarboxylase) inhibitor, so it reduces the peripheral conversion of L-DOPA to dopamine, and so reduces GI side effects
This enables the L-DOPA to cross the BBB so it can be converted to dopamine
