BSC 215 CNS
what are g-proteins
enzymes associated with metabotropic receptors and they activate a metabolic pathway that ends in the formation of a second messenger
neuropeptide y
function in feeding behaviors
what neurotransmitters have largely inhibitory effects
glycine and GABA
neuropeptides
group of neurotransmitters that have a wide variety of effects within the nervous system
dopamine
helps to coordinate movement, involved in emotion and motivation
what is histamine synthesized from
histidine
norepinephrine
influences functions such as heart rate, blood pressure, and digestion
neuronal pools
interneurons within the CNS
spatial summation
involves the simultaneous release of neurotransmitters from the axon terminals of multiple presynaptic neurons
what are the classes of neurotransmitter receptors
ionotropic and metabotropic
serotonin
mood regulation and is a common treatment for depression
inhibitory postsynaptic potential
moving the membrane of the postsynaptic neuron further away from threshold
the patterns of synaptic connection between neuronal pools
neural circuit
degradation
neurotransmitters are degraded by enzymatic reactions in the synaptic cleft
reuptake
neurotransmitters are taken back into the presynaptic neuron
diffusion and absorption
neurotransmitters diffuse away from the synaptic cleft and are returned to the presynaptic neuron
what are the 3 catecholamines
norepinephrine, epinephrine, and dopamine
electrical synapse
occurs between cells that are electrically coupled via gap junctions
temporal summation
occurs when neurotransmitter is released repeatedly from the axon terminal of a single presynaptic neuron
histamine
regulation of arousal and attention, mediator of allergic responses
functions of biogenic amines
regulation of homeostasis and cognition
substance p
released from type C sensory afferent fibers that carry information about pain and temperautre
what are the 3 neuropeptides
substance p, opioids, neuropeptide y
what are the two main features of an electrical synapse
synaptic transmission is directional and synaptic transmission is nearly instantaneous
synaptic transmission is nearly instantaneous
the delay between depolarization of the presynaptic neuron and change in potential of the postsynaptic neuron is less than 0.1ms
postsynaptic neuron
the neuron that is receiving the message from its dendrite, cell body, or axon
presynaptic neuron
the neuron that is sending the message from its axon terminal
what neurotransmitters have largely excitatory effects
acetylcholine, epinephrine, norepinephrine, dopamine, sero- tonin, histamine, and glutamate
summation
adding the input from several postsynaptic potentials to affect the membrane potential at the trigger zone
class of five neurotransmitters synthesized from amino acids
biogenic amines (monoamines)
antihistamines
block histamine receptors
excitatory postsynaptic potential
brings membrane of postsynaptic neuron closer to threshold
how is synaptic transmission terminated
by eliminating neuron-transmitter from the synaptic cleft
what are second messengers
can cause some kinds of ion channels to open and others to close
3 of the biogenic amines form a subgroup called
catecholamines
illegal drugs (dopamine)
cocaine and amphetamine
what are the 3 ways synaptic transmission can be terminated
diffusion and absorption, degradation, and reuptake
2 types of neural circuits
diverging and converging
synaptic transmission is bidirectional
either neuron may act as the presynaptic or the postsynaptic neuron and that current may flow in either direction between the two cells
opioids
elicit pain relief, nervous system depressants
3 opioids
endorphins, enkephalins, dynorphins
synaptic transmission
the transfer of chemical or electrical signals between neurons at a synapse
what is serotonin synthesized from
tryptophan
what amino acid are catecholamines synthesized from
tyrosine
what is the role of calcium ions in a chemical synapse
when an action potential reaches the presynaptic terminal, voltage-gated calcium ion channels open and calcium ions enter, the influx of calcium ions causes synaptic vesicles to release neurotransmitter into the synaptic cleft
epinephrine
widely used as a hormone by the endocrine system