Craviso: CNS Neurotransmission Flashcards
T/F: Average neuron forms ~ 1000 synaptic connections and receives even more
True
What is the activity of a neuron dependent on?
the ratio of excitatory to inhibitory inputs to that neuron
What are the small molecules involved in CNS functioning?
serotonin norepi dopamine ACh histamine
neurotransmitter; sleep, arousal, mood, appetite
serotonin
neurotransmitter; mood, arousal, appetite
norepi
neurotransmitter; movement (motor control), behavior, mood, perception
dopamine
neurotransmitter; arousal, cognition (memory and learning)
ACh
neurotransmitter; wakefulness, equilibrium
histamine
Excitatory amino acid neurotransmitter
glutamate (glutamic acid)
Inhibitory amino acid neurotransmitters
GABA
glycine
Neuropeptides involved in pain transmission
methionine
leucine enkephalin
substance P
Endocannabinoids involved in memory, cognition, and pain perception
anandamide
2-arachidonylglycerol
**post-synaptic neurons make endocannabinoids and they are retrograde NTs
Pattern of neuronal connectivity: Transmission is highly sequential and interconnected neurons are related to each other in a hierarchical fashion - e.g., primary sensory and motor pathways
Pain transmission!
long-hierarchical (relay)
Pattern of neuronal connectivity:
Neurons from a single anatomical location extend multiple, divergent connections to target cells outside the region in which the neurons originate
non-hierarchical, projecting
ex: serotonin, norepi, dopamine, ACh, 5HT
Where do serotonin neurons project from?
raphe nucleus
Functions of 5HT (serotonin)
sleep, arousal, mood behavioral changes hallucinations feeding behavior vomiting
Where do norepinephrine neurons project from?
locus coeruleus
Functions of norepinephrine
arousal and mood (frontal cortex)
appetite (hypothalamus)
cardiovascular control
Where do dopamine neurons project from?
midbrain
striatum
hypothalamus
Functions of dopamine
mood behavioral changes motor control (nigrostriatal pathway) neuroendocrine function vomiting
Where do ACh neurons project from?
forebrain and brainstem
Functions of ACh
arousal
learning and memory (think of Alzheimer’s disease)
motor control (nigrostriatal pathway)
The effects of cholinergic neurons can be via (blank) (GPCR) receptors or (blank) (ionotropic) receptors located presynaptically
muscarinic; nicotinic
Where do histamine neurons project from?
hypothalamus
Functions of histamine
arousal and wakefulness
equilibrium
effects on synthesis, storage, release, reuptake and/or degradation of neurotransmitters; agonist or antagonist activity at nerve terminal autoreceptors
pre-synaptic mechanisms by which neurotransmitters are modulated
receptor agonist, antagonist or modulatory activity; degradation of neurotransmitters
post-synaptic mechanisms by which neurotransmitters are modulated
**ACh is inactivated by degradation