neural networks and neural transmission Flashcards
the peripheral nervous sytems uses 2 principle neurotransmitters which are?
The PNS uses 2 principle neurotransmitters - ACh and NE
The CNS uses over 12 neurotransmitters which are to name a few?
The CNS uses >12 neurotransmitters ACh, NE, 5-HT, DA, Glu, GABA, …
what is a neurotransmitter and what is a neuromodulator?
Neurotransmitter
Dictionary: a substance released from the axon terminal of a presynaptic neuron on excitation, which diffuses across the synaptic cleft to either excite or inhibit the target cell.
Receptor linked ion channel-mediated EPSP or IPSP (AMPAR, GABAAR)
Lasts for only a few milliseconds
Receptor linked second messenger pathways can affect ion channels (Adenosine A1R, mGluR)
Neuromodulator
Dictionary: a substance that alters nerve impulse transmission.
Alters activity by acting on a receptor distant from release site
Lasts from milliseconds to 1 second (or longer)
A slow signal ‘modulates’ other fast NT signals on same neuron
Affects many sites/neurons
what are the steps in neurotransmission?
DNA / RNA / protein synthesis
axo-plasmic transport
neurotransmitter synthesis and storage
action potential (tetrodotoxin)
Membrane depol. opens Ca2+ channels
neurotransmitter release
neurotransmitter receptor coupling
neurotransmitter removal
- reuptake - metabolismwhat is norepinephrin neurotransmission involved in?
the reticular activating system: basic arousal, alertness, wakefulness, insomnia
the limbic system: anxiety, depression, appropriateness
central responses to stress
Both NE and E in the pons-medulla affect cardiovascular control
the hypothalamus: feeding, thermoregulation
what is the locus coeruleus (LC)?
The Locus Coeruleus (LC) is a pontine nucleus containing the sole source of noradrenergic neurons innervating the cerebral cortex
less than 10% of LC projection neurons in the cortex form conventional synapses (pre and post-synapse; Cohen et al. 1997)
what is dopamine involved in?
neurotransmission is involved in:
the extrapyramidal motor system: Parkinson’s disease (PD)
the limbic system: psychosis, anxiety, depression
the hypothalamus: reward/pleasure, pituitary secretion, thermoregulation
the chemoreceptive trigger zone: emesis
what is serotonin neurotransmission involved in?
the limbic system: psychosis, anxiety, depression
the hypothalamus: thermoregulation, pituitary secretion
Helps shape cortical circuits
what is acetylcholine neurotransmission involved in?
the limbic system: emotions, memory
the extrapyramidal motor system: Parkinson’s disease
Helps shape neural circuits
what is histamine neurotransmission involved in?
reticular activating system: arousal
what is glutamic acid (glutamate) and gamma amino butyric acid (GABA) neurotransmission involved in?
GLUTAMIC ACID (Glutamate)
Neurotransmission is involved in:
the limbic system: learning, memory
everywhere: main excitatory neurotransmitter, epilepsy
neurodegeneration if excessive (excitotoxicity)
4 glutamate receptors have been identified
NMDA / AMPA / Kainate / mGlu
over-stimulation of the NMDA receptor produces a massive increase in intracellular calcium which ends up killing the neuron
GAMMA AMINO BUTYRIC ACID (GABA)
Neurotransmission is involved in:
the extrapyramidal motor system: Parkinson’s disease and Huntington’s disease
the limbic system: psychosis, anxiety, depression
everywhere: main inhibitory neurotransmitter, epilepsy
what is substance P and endorphin/enkephalin/dynorphin neurotransmission involved in?
substance P
the spinal cord: pain
the thalamus: pain
capsaicin in chili peppers stimulates substance P receptors giving Mexican food its kick
ENDORPHIN / ENKEPHALIN / DYNORPHIN
the limbic system: emotions, memory, stress adaptation, addiction
the spinal cord: analgesia
the thalamus: analgesia
