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